Double Jointed?<\/h1>\r\n<\/div>\r\nIs this woman double jointed? No, there is actually no such thing \u2014 at least as far as humans are concerned. However, some people, like the woman pictured in Figure 11.6.1, are much more flexible than others, generally because they have looser ligaments. Physicians call this condition joint hypermobility. Regardless of what it\u2019s called, the feats of people with highly mobile joints can be quite impressive.\r\n\r\nWhat Are Joints?<\/h1>\r\n<\/div>\r\n[pb_glossary id=\"3949\"]Joints<\/strong>\u00a0[\/pb_glossary]are locations at which\u00a0bones\u00a0of the skeleton connect with one another. A joint is also called an articulation. The majority of joints are structured in such a way that they allow movement. However, not all joints allow movement. Of joints that\u00a0do<\/em>\u00a0allow movement, the extent and direction of the movements they allow also vary.\r\n\r\nClassification\u00a0of Joints<\/h1>\r\n<\/div>\r\nJoints can be classified structurally or functionally. The structural\u00a0classification\u00a0of joints depends on the manner in which the\u00a0bones\u00a0connect to each other. The functional classification of joints depends on the nature of the movement the joints allow. There is significant overlap between the two types of classifications, because function depends largely on structure.\r\nStructural Classification of Joints<\/h2>\r\nThe structural classification of joints is based on the type of tissue that binds the\u00a0bones\u00a0to each other at the joint. There are three types of joints in the structural classification: fibrous, cartilaginous, and synovial joints.\r\n\r\n \t- [pb_glossary id=\"4084\"]Fibrous joints[\/pb_glossary]<\/strong> are joints in which bones are joined by dense connective tissue that is rich in collagen fibres. These joints are also called sutures. The joints between bones of the cranium are fibrous joints.<\/li>\r\n \t
- [pb_glossary id=\"4085\"]Cartilaginous joints[\/pb_glossary]<\/strong>\u00a0are joints in which bones are joined by cartilage. The joints between most of the vertebrae in the spine are cartilaginous joints.<\/li>\r\n \t
- [pb_glossary id=\"4086\"]Synovial joints[\/pb_glossary]<\/strong> are characterized by a fluid-filled space (called a synovial cavity) between the bones of the joints. You can see a drawing of a typical synovial joint in Figure 11.6.2. The cavity is enclosed by a membrane and filled with a fluid (called synovial fluid) that provides extra cushioning to the ends of the bones. Cartilage covers the articulating surfaces of the two bones, but the bones are actually held together by ligaments. The knee is a synovial joint.<\/li>\r\n<\/ol>\r\n[caption id=\"attachment_4087\" align=\"aligncenter\" width=\"483\"]
![\"11.6.2](\"https:\/\/pressbooks.ccconline.org\/acchumanbio\/wp-content\/uploads\/sites\/152\/2023\/10\/Synovial_Joints-2.jpg\")
Figure 11.6.2 A typical synovial joint is represented by this diagram.<\/em>[\/caption]\r\nFunctional Classification of Joints<\/h2>\r\nThe functional classification of joints is based on the type and degree of movement that they allow. There are three types of joints in the functional classification: immovable, partly movable, and movable joints.\r\n\r\n \t- [pb_glossary id=\"4088\"]Immovable joints[\/pb_glossary]<\/strong>\u00a0allow little or no movement at the joint. Most immovable joints are fibrous joints. Besides the bones of the cranium, immovable joints include joints between the tibia and fibula in the lower leg, and between the radius and ulna in the lower arm.<\/li>\r\n \t
- [pb_glossary id=\"4090\"]Partly movable joints[\/pb_glossary]<\/strong>\u00a0permit slight movement. Most partly movable joints are cartilaginous joints. Besides the joints between vertebrae, they include the joints between the ribs and sternum (breast bone).<\/li>\r\n \t
- [pb_glossary id=\"5641\"]Movable joints[\/pb_glossary]<\/strong>\u00a0allow bones to move freely. All movable joints are synovial joints. Besides the knee, they include the shoulder, hip, and elbow. Movable joints are the most common type of joints in the body.<\/li>\r\n<\/ol>\r\n
Types of Movable Joints<\/h2>\r\nMovable joints can be classified further according to the type of movement they allow. There are six classes of movable joints: pivot, hinge, saddle, plane, condyloid, and ball-and-socket joints. An example of each class \u2014 as well as the type of movement it allows \u2014 is shown in Figure 11.6.3.\r\n\r\n\r\n[caption id=\"attachment_4099\" align=\"aligncenter\" width=\"985\"]![\"11.6.3](\"https:\/\/pressbooks.ccconline.org\/acchumanbio\/wp-content\/uploads\/sites\/152\/2023\/10\/Types_of_Synovial_Joints-2.jpg\")
Figure 11.6.3 This diagram shows the six classes of movable joints in the human body. All of these joints are synovial joints.<\/em>[\/caption]\r\n\r\n<\/div>\r\n\r\n \t- A\u00a0[pb_glossary id=\"4093\"]ball-and-socket joint[\/pb_glossary]<\/strong> allows the greatest range of movement of any movable joint. It allows forward and backward motion, as well as upward and downward movement. It also allows rotation in a circle. The hip and shoulder are the only two ball-and-socket joints in the human body.<\/li>\r\n \t
- A\u00a0[pb_glossary id=\"4094\"]pivot joint[\/pb_glossary]<\/strong>\u00a0allows one bone to rotate around another. An example of a pivot joint is the joint between the first two vertebrae in the spine. This joint allows the head to rotate from left to right and back again.<\/li>\r\n \t
- A\u00a0[pb_glossary id=\"4096\"]hinge joint[\/pb_glossary]<\/strong>\u00a0allows back and forth movement like the hinge of a door. An example of a hinge joint is the elbow. This joint allows the arm to bend back and forth.<\/li>\r\n \t
- A\u00a0[pb_glossary id=\"4098\"]saddle joint[\/pb_glossary]<\/strong>\u00a0allows two different types of movement. An example of a saddle joint is the joint between the first metacarpal bone in the hand and one of the carpal bones in the wrist. This joint allows the thumb to move toward and away from the index finger, and also to cross over the palm toward the little finger.<\/li>\r\n \t
- A\u00a0[pb_glossary id=\"4100\"]plane joint[\/pb_glossary]<\/strong>\u00a0(also called a gliding joint) allows two bones\u00a0to\u00a0glide over one another. The joints between the tarsals in the ankles and between the carpals in the wrists are mainly gliding joints. In the wrist, this type of joint allows the hand to bend upward at the wrist, and also to wave from side to side while the lower arm is held steady.<\/li>\r\n \t
- A\u00a0[pb_glossary id=\"5483\"]condyloid joint[\/pb_glossary]<\/strong>\u00a0is one in which an oval-shaped head on one bone moves in an elliptical cavity in another bone, allowing movement in all directions, except rotation around an axis. The joint between the radius in the lower arm and carpal bones of the wrist is a condyloid joint, as is the joint at the\u00a0base\u00a0of the index finger.<\/li>\r\n<\/ul>\r\n\r\n
Feature: My\u00a0Human Body<\/h1>\r\n<\/div>\r\nOf all the parts of the\u00a0skeletal system, the joints are generally the most fragile and subject to damage. If the cartilage that cushions bones at joints wears away, it does not grow back. Eventually, all of the cartilage may wear away. This causes [pb_glossary id=\"4102\"]osteoarthritis[\/pb_glossary], which can be both painful and debilitating. In serious cases of osteoarthritis<\/a>, people may lose the ability to climb stairs, walk long distances, perform routine daily activities, or participate in activities they love, such as gardening or playing sports. If you protect your joints, you can reduce your chances of joint damage, pain, and disability. If you already have joint damage, it is equally important to protect your joints and limit further damage. Follow these five tips:\r\n\r\n \t- Maintain a normal, healthy<\/strong>\u00a0<\/strong>weight.<\/strong>\u00a0The\u00a0more you weigh, the more force you exert on your joints. When you walk, each knee has to bear a force equal to as much as\u00a0six times<\/em>\u00a0your body\u00a0weight. If a person weighs 200 pounds, each knee bears more than half a ton of weight with every step. Seven in ten knee replacement surgeries for osteoarthritis can be attributed to\u00a0obesity.<\/li>\r\n \t
- Avoid too much high-impact<\/strong>\u00a0<\/strong>exercise.<\/strong>\u00a0Examples of high-impact activities include volleyball, basketball, and tennis. These activities generally involve running or jumping on hard surfaces, which puts tremendous stress on weight-bearing joints, especially the knees. Replace some or all of your high-impact activities with low-impact activities, such as biking, swimming, yoga, or lifting light weights.<\/li>\r\n \t
- Reduce your risk of injury.<\/strong>\u00a0Don\u2019t be a weekend warrior, sitting at a desk all week and then crowding all your physical activity into two days. Get involved in a regular, daily\u00a0exercise\u00a0routine that keeps your body fit and your\u00a0muscles\u00a0toned. Building up muscles will make your joints more stable, allowing stress to spread across them. Be sure to do some stretching every day to keep the muscles around joints flexible and less prone to injury.<\/li>\r\n \t
- Distribute work over your body, and use your largest, strongest joints.<\/strong>\u00a0Use your shoulder, elbow, and wrist to lift heavy objects \u2014 not just your fingers. Hold small items in the palm of your hand, rather than by the fingers. Carry heavy items in a backpack, rather than in your hands. Hold weighty objects close to your body, instead of at arms\u2019 length. Lift with your hips and knees, not your back.<\/li>\r\n \t
- Respect pain.<\/strong>\u00a0If it hurts, stop doing it. Take a break from the activity \u2014 at least until the pain stops. Try to use joints only to the point of mild fatigue, not pain.<\/li>\r\n<\/ol>\r\n\r\n
\r\n11.6 Summary<\/span><\/h1>\r\n<\/header>\r\n\r\n\r\n \t- [pb_glossary id=\"3949\"]Joints[\/pb_glossary]\u00a0are\u00a0spots\u00a0at which [pb_glossary id=\"5913\"]bones[\/pb_glossary]\u00a0of the skeleton connect with one another. A joint is also called an articulation.<\/li>\r\n \t
- Joints can be classified structurally or functionally, and there is significant overlap between the two types of classifications.<\/li>\r\n \t
- The structural classification of joints depends on the type of tissue that binds the bones to each other at the joint. There are three types of joints in the structural classification: [pb_glossary id=\"4084\"]fibrous[\/pb_glossary], [pb_glossary id=\"4085\"]cartilaginous[\/pb_glossary], and [pb_glossary id=\"4086\"]synovial joints[\/pb_glossary].<\/li>\r\n \t
- The functional classification of joints is based on the type and degree of movement that they allow. There are three types of joints in the functional classification: [pb_glossary id=\"4088\"]immovable[\/pb_glossary], [pb_glossary id=\"4090\"]partly movable[\/pb_glossary], and [pb_glossary id=\"5641\"]movable joints[\/pb_glossary].<\/li>\r\n \t
- Movable joints can be classified further according to the type of movement they allow. There are six classes of movable joints: [pb_glossary id=\"4094\"]pivot[\/pb_glossary], [pb_glossary id=\"4096\"]hinge[\/pb_glossary], [pb_glossary id=\"4098\"]saddle[\/pb_glossary], [pb_glossary id=\"4100\"]plane[\/pb_glossary], [pb_glossary id=\"5483\"]condyloid[\/pb_glossary], and [pb_glossary id=\"4093\"]ball-and-socket joints[\/pb_glossary].<\/li>\r\n<\/ul>\r\n<\/div>\r\n<\/div>\r\n
\r\n11.6 Review Questions<\/span><\/h1>\r\n<\/header>\r\n\r\n\r\n \t- What are joints?<\/li>\r\n \t
- What are two ways that joints are commonly classified?<\/li>\r\n \t
- [h5p id=\"597\"]<\/li>\r\n \t
- How are joints classified structurally?<\/li>\r\n \t
- Describe the functional classification of joints.<\/li>\r\n \t
- How are movable joints classified?<\/li>\r\n \t
- Name the six classes of movable joints. Describe how they move and give an example of each.<\/li>\r\n \t
- Which specific type of moveable joint do you think your knee joint is? Explain your reasoning.<\/li>\r\n \t
- Explain the difference between cartilage in a cartilaginous joint and cartilage in a synovial joint.<\/li>\r\n \t
- Why are fibrous joints immovable?<\/li>\r\n \t
- What is the function of synovial fluid?<\/li>\r\n<\/ol>\r\n<\/div>\r\n<\/div>\r\n
\r\n11.6 Explore More<\/span><\/h1>\r\n<\/header>\r\n\r\n\r\nhttps:\/\/www.youtube.com\/watch?v=IjiKUmfaZr4\r\nWhy do your knuckles pop? - Eleanor Nelsen, TED-Ed, 2015.<\/p>\r\nhttps:\/\/www.youtube.com\/watch?v=FWsBm3hr3B0\r\n
Why haven\u2019t we cured arthritis? - Kaitlyn Sadtler and Heather J. Faust, TED-Ed, 2019.<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n \r\n\r\n<\/div>\r\n
Attributions<\/h2>\r\nFigure 11.6.1<\/strong>\r\n\r\nTags: Sports Gymnastics Fitness Woman Preparation<\/a> by nastya_gepp<\/a> on Pixabay<\/a> is used under the Pixabay License<\/a> (https:\/\/pixabay.com\/de\/service\/license\/).\r\n\r\nFigure 11.6.2<\/strong>\r\n\r\nSynovial_Joints<\/a> by OpenStax College<\/a> on Wikimedia Commons is used under a CC BY 3.0 <\/a>(https:\/\/creativecommons.org\/licenses\/by\/3.0) license.\r\n\r\nFigure 11.6.3<\/strong>\r\n\r\nTypes_of_Synovial_Joints<\/a>\u00a0by OpenStax College<\/a> on Wikimedia Commons is used under a CC BY 3.0 <\/a>(https:\/\/creativecommons.org\/licenses\/by\/3.0) license.\r\nReferences<\/h2>\r\n
Betts, J. G., Young, K.A., Wise, J.A., Johnson, E., Poe, B., Kruse, D.H., Korol, O., Johnson, J.E., Womble, M., DeSaix, P. (2013, June 19). Figure\u00a0<\/span><\/span>9.8<\/span><\/span>\u00a0<\/span>Synovial joints<\/span><\/span> [digital image].\u00a0 In Anatomy and Physiology<\/em> (Section 9.4). OpenStax. https:\/\/openstax.org\/books\/anatomy-and-physiology\/pages\/9-4-synovial-joints<\/p>\r\nBetts, J. G., Young, K.A., Wise, J.A., Johnson, E., Poe, B., Kruse, D.H., Korol, O., Johnson, J.E., Womble, M., DeSaix, P. (2013, June 19). Figure 9.10 Types of synovial joints [digital image].\u00a0 In Anatomy and Physiology<\/em> (Section 9.4). OpenStax. https:\/\/openstax.org\/books\/anatomy-and-physiology\/pages\/9-4-synovial-joints<\/p>\r\nMayo Clinic Staff. (n.d.). Osteoarthritis [online article]. MayoClinic.org. https:\/\/www.mayoclinic.org\/diseases-conditions\/osteoarthritis\/symptoms-causes\/syc-20351925<\/p>\r\n
TED-Ed. (2015, May 5). Why do your knuckles pop? - Eleanor Nelsen. YouTube. https:\/\/www.youtube.com\/watch?v=IjiKUmfaZr4<\/p>\r\n
TED-Ed. (2019, November 7). Why haven\u2019t we cured arthritis? - Kaitlyn Sadtler and Heather J. Faust. YouTube. https:\/\/www.youtube.com\/watch?v=FWsBm3hr3B0<\/p>\r\n ","rendered":"
<\/p>\n![\"A](\"https:\/\/pressbooks.ccconline.org\/acchumanbio\/wp-content\/uploads\/sites\/152\/2019\/06\/woman-in-black-tank-top-and-black-shorts-lying-on-floor-e1606261742472-2.jpg\")
Figure 11.6.1 That’s quite a stretch!<\/em><\/figcaption><\/figure>\n\nDouble Jointed?<\/h1>\n<\/div>\n
Is this woman double jointed? No, there is actually no such thing \u2014 at least as far as humans are concerned. However, some people, like the woman pictured in Figure 11.6.1, are much more flexible than others, generally because they have looser ligaments. Physicians call this condition joint hypermobility. Regardless of what it\u2019s called, the feats of people with highly mobile joints can be quite impressive.<\/p>\n
\nWhat Are Joints?<\/h1>\n<\/div>\n
Joints<\/strong>\u00a0<\/a>are locations at which\u00a0bones\u00a0of the skeleton connect with one another. A joint is also called an articulation. The majority of joints are structured in such a way that they allow movement. However, not all joints allow movement. Of joints that\u00a0do<\/em>\u00a0allow movement, the extent and direction of the movements they allow also vary.<\/p>\n\nClassification\u00a0of Joints<\/h1>\n<\/div>\n
Joints can be classified structurally or functionally. The structural\u00a0classification\u00a0of joints depends on the manner in which the\u00a0bones\u00a0connect to each other. The functional classification of joints depends on the nature of the movement the joints allow. There is significant overlap between the two types of classifications, because function depends largely on structure.<\/p>\n
Structural Classification of Joints<\/h2>\n
The structural classification of joints is based on the type of tissue that binds the\u00a0bones\u00a0to each other at the joint. There are three types of joints in the structural classification: fibrous, cartilaginous, and synovial joints.<\/p>\n
\n- Fibrous joints<\/a><\/strong> are joints in which bones are joined by dense connective tissue that is rich in collagen fibres. These joints are also called sutures. The joints between bones of the cranium are fibrous joints.<\/li>\n
- Cartilaginous joints<\/a><\/strong>\u00a0are joints in which bones are joined by cartilage. The joints between most of the vertebrae in the spine are cartilaginous joints.<\/li>\n
- Synovial joints<\/a><\/strong> are characterized by a fluid-filled space (called a synovial cavity) between the bones of the joints. You can see a drawing of a typical synovial joint in Figure 11.6.2. The cavity is enclosed by a membrane and filled with a fluid (called synovial fluid) that provides extra cushioning to the ends of the bones. Cartilage covers the articulating surfaces of the two bones, but the bones are actually held together by ligaments. The knee is a synovial joint.<\/li>\n<\/ol>\n
Figure 11.6.2 A typical synovial joint is represented by this diagram.<\/em><\/figcaption><\/figure>\nFunctional Classification of Joints<\/h2>\n
The functional classification of joints is based on the type and degree of movement that they allow. There are three types of joints in the functional classification: immovable, partly movable, and movable joints.<\/p>\n
\n- Immovable joints<\/a><\/strong>\u00a0allow little or no movement at the joint. Most immovable joints are fibrous joints. Besides the bones of the cranium, immovable joints include joints between the tibia and fibula in the lower leg, and between the radius and ulna in the lower arm.<\/li>\n
- Partly movable joints<\/a><\/strong>\u00a0permit slight movement. Most partly movable joints are cartilaginous joints. Besides the joints between vertebrae, they include the joints between the ribs and sternum (breast bone).<\/li>\n
- Movable joints<\/a><\/strong>\u00a0allow bones to move freely. All movable joints are synovial joints. Besides the knee, they include the shoulder, hip, and elbow. Movable joints are the most common type of joints in the body.<\/li>\n<\/ol>\n
Types of Movable Joints<\/h2>\n
Movable joints can be classified further according to the type of movement they allow. There are six classes of movable joints: pivot, hinge, saddle, plane, condyloid, and ball-and-socket joints. An example of each class \u2014 as well as the type of movement it allows \u2014 is shown in Figure 11.6.3.<\/p>\n
\nFigure 11.6.3 This diagram shows the six classes of movable joints in the human body. All of these joints are synovial joints.<\/em><\/figcaption><\/figure>\n<\/div>\n\n- A\u00a0ball-and-socket joint<\/a><\/strong> allows the greatest range of movement of any movable joint. It allows forward and backward motion, as well as upward and downward movement. It also allows rotation in a circle. The hip and shoulder are the only two ball-and-socket joints in the human body.<\/li>\n
- A\u00a0pivot joint<\/a><\/strong>\u00a0allows one bone to rotate around another. An example of a pivot joint is the joint between the first two vertebrae in the spine. This joint allows the head to rotate from left to right and back again.<\/li>\n
- A\u00a0hinge joint<\/a><\/strong>\u00a0allows back and forth movement like the hinge of a door. An example of a hinge joint is the elbow. This joint allows the arm to bend back and forth.<\/li>\n
- A\u00a0saddle joint<\/a><\/strong>\u00a0allows two different types of movement. An example of a saddle joint is the joint between the first metacarpal bone in the hand and one of the carpal bones in the wrist. This joint allows the thumb to move toward and away from the index finger, and also to cross over the palm toward the little finger.<\/li>\n
- A\u00a0plane joint<\/a><\/strong>\u00a0(also called a gliding joint) allows two bones\u00a0to\u00a0glide over one another. The joints between the tarsals in the ankles and between the carpals in the wrists are mainly gliding joints. In the wrist, this type of joint allows the hand to bend upward at the wrist, and also to wave from side to side while the lower arm is held steady.<\/li>\n
- A\u00a0condyloid joint<\/a><\/strong>\u00a0is one in which an oval-shaped head on one bone moves in an elliptical cavity in another bone, allowing movement in all directions, except rotation around an axis. The joint between the radius in the lower arm and carpal bones of the wrist is a condyloid joint, as is the joint at the\u00a0base\u00a0of the index finger.<\/li>\n<\/ul>\n\n
Feature: My\u00a0Human Body<\/h1>\n<\/div>\n
Of all the parts of the\u00a0skeletal system, the joints are generally the most fragile and subject to damage. If the cartilage that cushions bones at joints wears away, it does not grow back. Eventually, all of the cartilage may wear away. This causes osteoarthritis<\/a>, which can be both painful and debilitating. In serious cases of osteoarthritis<\/a>, people may lose the ability to climb stairs, walk long distances, perform routine daily activities, or participate in activities they love, such as gardening or playing sports. If you protect your joints, you can reduce your chances of joint damage, pain, and disability. If you already have joint damage, it is equally important to protect your joints and limit further damage. Follow these five tips:<\/p>\n\n- Maintain a normal, healthy<\/strong>\u00a0<\/strong>weight.<\/strong>\u00a0The\u00a0more you weigh, the more force you exert on your joints. When you walk, each knee has to bear a force equal to as much as\u00a0six times<\/em>\u00a0your body\u00a0weight. If a person weighs 200 pounds, each knee bears more than half a ton of weight with every step. Seven in ten knee replacement surgeries for osteoarthritis can be attributed to\u00a0obesity.<\/li>\n
- Avoid too much high-impact<\/strong>\u00a0<\/strong>exercise.<\/strong>\u00a0Examples of high-impact activities include volleyball, basketball, and tennis. These activities generally involve running or jumping on hard surfaces, which puts tremendous stress on weight-bearing joints, especially the knees. Replace some or all of your high-impact activities with low-impact activities, such as biking, swimming, yoga, or lifting light weights.<\/li>\n
- Reduce your risk of injury.<\/strong>\u00a0Don\u2019t be a weekend warrior, sitting at a desk all week and then crowding all your physical activity into two days. Get involved in a regular, daily\u00a0exercise\u00a0routine that keeps your body fit and your\u00a0muscles\u00a0toned. Building up muscles will make your joints more stable, allowing stress to spread across them. Be sure to do some stretching every day to keep the muscles around joints flexible and less prone to injury.<\/li>\n
- Distribute work over your body, and use your largest, strongest joints.<\/strong>\u00a0Use your shoulder, elbow, and wrist to lift heavy objects \u2014 not just your fingers. Hold small items in the palm of your hand, rather than by the fingers. Carry heavy items in a backpack, rather than in your hands. Hold weighty objects close to your body, instead of at arms\u2019 length. Lift with your hips and knees, not your back.<\/li>\n
- Respect pain.<\/strong>\u00a0If it hurts, stop doing it. Take a break from the activity \u2014 at least until the pain stops. Try to use joints only to the point of mild fatigue, not pain.<\/li>\n<\/ol>\n\n\n
\n11.6 Summary<\/span><\/h1>\n<\/header>\n\n\n- Joints<\/a>\u00a0are\u00a0spots\u00a0at which bones<\/a>\u00a0of the skeleton connect with one another. A joint is also called an articulation.<\/li>\n
- Joints can be classified structurally or functionally, and there is significant overlap between the two types of classifications.<\/li>\n
- The structural classification of joints depends on the type of tissue that binds the bones to each other at the joint. There are three types of joints in the structural classification: fibrous<\/a>, cartilaginous<\/a>, and synovial joints<\/a>.<\/li>\n
- The functional classification of joints is based on the type and degree of movement that they allow. There are three types of joints in the functional classification: immovable<\/a>, partly movable<\/a>, and movable joints<\/a>.<\/li>\n
- Movable joints can be classified further according to the type of movement they allow. There are six classes of movable joints: pivot<\/a>, hinge<\/a>, saddle<\/a>, plane<\/a>, condyloid<\/a>, and ball-and-socket joints<\/a>.<\/li>\n<\/ul>\n<\/div>\n<\/div>\n\n
\n11.6 Review Questions<\/span><\/h1>\n<\/header>\n\n\n- What are joints?<\/li>\n
- What are two ways that joints are commonly classified?<\/li>\n
- \n\n
What Are Joints?<\/h1>\r\n<\/div>\r\n[pb_glossary id=\"3949\"]Joints<\/strong>\u00a0[\/pb_glossary]are locations at which\u00a0bones\u00a0of the skeleton connect with one another. A joint is also called an articulation. The majority of joints are structured in such a way that they allow movement. However, not all joints allow movement. Of joints that\u00a0do<\/em>\u00a0allow movement, the extent and direction of the movements they allow also vary.\r\n\r\nClassification\u00a0of Joints<\/h1>\r\n<\/div>\r\nJoints can be classified structurally or functionally. The structural\u00a0classification\u00a0of joints depends on the manner in which the\u00a0bones\u00a0connect to each other. The functional classification of joints depends on the nature of the movement the joints allow. There is significant overlap between the two types of classifications, because function depends largely on structure.\r\nStructural Classification of Joints<\/h2>\r\nThe structural classification of joints is based on the type of tissue that binds the\u00a0bones\u00a0to each other at the joint. There are three types of joints in the structural classification: fibrous, cartilaginous, and synovial joints.\r\n\r\n \t- [pb_glossary id=\"4084\"]Fibrous joints[\/pb_glossary]<\/strong> are joints in which bones are joined by dense connective tissue that is rich in collagen fibres. These joints are also called sutures. The joints between bones of the cranium are fibrous joints.<\/li>\r\n \t
- [pb_glossary id=\"4085\"]Cartilaginous joints[\/pb_glossary]<\/strong>\u00a0are joints in which bones are joined by cartilage. The joints between most of the vertebrae in the spine are cartilaginous joints.<\/li>\r\n \t
- [pb_glossary id=\"4086\"]Synovial joints[\/pb_glossary]<\/strong> are characterized by a fluid-filled space (called a synovial cavity) between the bones of the joints. You can see a drawing of a typical synovial joint in Figure 11.6.2. The cavity is enclosed by a membrane and filled with a fluid (called synovial fluid) that provides extra cushioning to the ends of the bones. Cartilage covers the articulating surfaces of the two bones, but the bones are actually held together by ligaments. The knee is a synovial joint.<\/li>\r\n<\/ol>\r\n[caption id=\"attachment_4087\" align=\"aligncenter\" width=\"483\"] Figure 11.6.2 A typical synovial joint is represented by this diagram.<\/em>[\/caption]\r\n
Functional Classification of Joints<\/h2>\r\nThe functional classification of joints is based on the type and degree of movement that they allow. There are three types of joints in the functional classification: immovable, partly movable, and movable joints.\r\n\r\n \t- [pb_glossary id=\"4088\"]Immovable joints[\/pb_glossary]<\/strong>\u00a0allow little or no movement at the joint. Most immovable joints are fibrous joints. Besides the bones of the cranium, immovable joints include joints between the tibia and fibula in the lower leg, and between the radius and ulna in the lower arm.<\/li>\r\n \t
- [pb_glossary id=\"4090\"]Partly movable joints[\/pb_glossary]<\/strong>\u00a0permit slight movement. Most partly movable joints are cartilaginous joints. Besides the joints between vertebrae, they include the joints between the ribs and sternum (breast bone).<\/li>\r\n \t
- [pb_glossary id=\"5641\"]Movable joints[\/pb_glossary]<\/strong>\u00a0allow bones to move freely. All movable joints are synovial joints. Besides the knee, they include the shoulder, hip, and elbow. Movable joints are the most common type of joints in the body.<\/li>\r\n<\/ol>\r\n
Types of Movable Joints<\/h2>\r\nMovable joints can be classified further according to the type of movement they allow. There are six classes of movable joints: pivot, hinge, saddle, plane, condyloid, and ball-and-socket joints. An example of each class \u2014 as well as the type of movement it allows \u2014 is shown in Figure 11.6.3.\r\n\r\n\r\n[caption id=\"attachment_4099\" align=\"aligncenter\" width=\"985\"] Figure 11.6.3 This diagram shows the six classes of movable joints in the human body. All of these joints are synovial joints.<\/em>[\/caption]\r\n\r\n<\/div>\r\n\r\n \t- A\u00a0[pb_glossary id=\"4093\"]ball-and-socket joint[\/pb_glossary]<\/strong> allows the greatest range of movement of any movable joint. It allows forward and backward motion, as well as upward and downward movement. It also allows rotation in a circle. The hip and shoulder are the only two ball-and-socket joints in the human body.<\/li>\r\n \t
- A\u00a0[pb_glossary id=\"4094\"]pivot joint[\/pb_glossary]<\/strong>\u00a0allows one bone to rotate around another. An example of a pivot joint is the joint between the first two vertebrae in the spine. This joint allows the head to rotate from left to right and back again.<\/li>\r\n \t
- A\u00a0[pb_glossary id=\"4096\"]hinge joint[\/pb_glossary]<\/strong>\u00a0allows back and forth movement like the hinge of a door. An example of a hinge joint is the elbow. This joint allows the arm to bend back and forth.<\/li>\r\n \t
- A\u00a0[pb_glossary id=\"4098\"]saddle joint[\/pb_glossary]<\/strong>\u00a0allows two different types of movement. An example of a saddle joint is the joint between the first metacarpal bone in the hand and one of the carpal bones in the wrist. This joint allows the thumb to move toward and away from the index finger, and also to cross over the palm toward the little finger.<\/li>\r\n \t
- A\u00a0[pb_glossary id=\"4100\"]plane joint[\/pb_glossary]<\/strong>\u00a0(also called a gliding joint) allows two bones\u00a0to\u00a0glide over one another. The joints between the tarsals in the ankles and between the carpals in the wrists are mainly gliding joints. In the wrist, this type of joint allows the hand to bend upward at the wrist, and also to wave from side to side while the lower arm is held steady.<\/li>\r\n \t
- A\u00a0[pb_glossary id=\"5483\"]condyloid joint[\/pb_glossary]<\/strong>\u00a0is one in which an oval-shaped head on one bone moves in an elliptical cavity in another bone, allowing movement in all directions, except rotation around an axis. The joint between the radius in the lower arm and carpal bones of the wrist is a condyloid joint, as is the joint at the\u00a0base\u00a0of the index finger.<\/li>\r\n<\/ul>\r\n\r\n
Feature: My\u00a0Human Body<\/h1>\r\n<\/div>\r\nOf all the parts of the\u00a0skeletal system, the joints are generally the most fragile and subject to damage. If the cartilage that cushions bones at joints wears away, it does not grow back. Eventually, all of the cartilage may wear away. This causes [pb_glossary id=\"4102\"]osteoarthritis[\/pb_glossary], which can be both painful and debilitating. In serious cases of osteoarthritis<\/a>, people may lose the ability to climb stairs, walk long distances, perform routine daily activities, or participate in activities they love, such as gardening or playing sports. If you protect your joints, you can reduce your chances of joint damage, pain, and disability. If you already have joint damage, it is equally important to protect your joints and limit further damage. Follow these five tips:\r\n\r\n \t- Maintain a normal, healthy<\/strong>\u00a0<\/strong>weight.<\/strong>\u00a0The\u00a0more you weigh, the more force you exert on your joints. When you walk, each knee has to bear a force equal to as much as\u00a0six times<\/em>\u00a0your body\u00a0weight. If a person weighs 200 pounds, each knee bears more than half a ton of weight with every step. Seven in ten knee replacement surgeries for osteoarthritis can be attributed to\u00a0obesity.<\/li>\r\n \t
- Avoid too much high-impact<\/strong>\u00a0<\/strong>exercise.<\/strong>\u00a0Examples of high-impact activities include volleyball, basketball, and tennis. These activities generally involve running or jumping on hard surfaces, which puts tremendous stress on weight-bearing joints, especially the knees. Replace some or all of your high-impact activities with low-impact activities, such as biking, swimming, yoga, or lifting light weights.<\/li>\r\n \t
- Reduce your risk of injury.<\/strong>\u00a0Don\u2019t be a weekend warrior, sitting at a desk all week and then crowding all your physical activity into two days. Get involved in a regular, daily\u00a0exercise\u00a0routine that keeps your body fit and your\u00a0muscles\u00a0toned. Building up muscles will make your joints more stable, allowing stress to spread across them. Be sure to do some stretching every day to keep the muscles around joints flexible and less prone to injury.<\/li>\r\n \t
- Distribute work over your body, and use your largest, strongest joints.<\/strong>\u00a0Use your shoulder, elbow, and wrist to lift heavy objects \u2014 not just your fingers. Hold small items in the palm of your hand, rather than by the fingers. Carry heavy items in a backpack, rather than in your hands. Hold weighty objects close to your body, instead of at arms\u2019 length. Lift with your hips and knees, not your back.<\/li>\r\n \t
- Respect pain.<\/strong>\u00a0If it hurts, stop doing it. Take a break from the activity \u2014 at least until the pain stops. Try to use joints only to the point of mild fatigue, not pain.<\/li>\r\n<\/ol>\r\n\r\n
\r\n11.6 Summary<\/span><\/h1>\r\n<\/header>\r\n\r\n\r\n \t- [pb_glossary id=\"3949\"]Joints[\/pb_glossary]\u00a0are\u00a0spots\u00a0at which [pb_glossary id=\"5913\"]bones[\/pb_glossary]\u00a0of the skeleton connect with one another. A joint is also called an articulation.<\/li>\r\n \t
- Joints can be classified structurally or functionally, and there is significant overlap between the two types of classifications.<\/li>\r\n \t
- The structural classification of joints depends on the type of tissue that binds the bones to each other at the joint. There are three types of joints in the structural classification: [pb_glossary id=\"4084\"]fibrous[\/pb_glossary], [pb_glossary id=\"4085\"]cartilaginous[\/pb_glossary], and [pb_glossary id=\"4086\"]synovial joints[\/pb_glossary].<\/li>\r\n \t
- The functional classification of joints is based on the type and degree of movement that they allow. There are three types of joints in the functional classification: [pb_glossary id=\"4088\"]immovable[\/pb_glossary], [pb_glossary id=\"4090\"]partly movable[\/pb_glossary], and [pb_glossary id=\"5641\"]movable joints[\/pb_glossary].<\/li>\r\n \t
- Movable joints can be classified further according to the type of movement they allow. There are six classes of movable joints: [pb_glossary id=\"4094\"]pivot[\/pb_glossary], [pb_glossary id=\"4096\"]hinge[\/pb_glossary], [pb_glossary id=\"4098\"]saddle[\/pb_glossary], [pb_glossary id=\"4100\"]plane[\/pb_glossary], [pb_glossary id=\"5483\"]condyloid[\/pb_glossary], and [pb_glossary id=\"4093\"]ball-and-socket joints[\/pb_glossary].<\/li>\r\n<\/ul>\r\n<\/div>\r\n<\/div>\r\n
\r\n11.6 Review Questions<\/span><\/h1>\r\n<\/header>\r\n\r\n\r\n \t- What are joints?<\/li>\r\n \t
- What are two ways that joints are commonly classified?<\/li>\r\n \t
- [h5p id=\"597\"]<\/li>\r\n \t
- How are joints classified structurally?<\/li>\r\n \t
- Describe the functional classification of joints.<\/li>\r\n \t
- How are movable joints classified?<\/li>\r\n \t
- Name the six classes of movable joints. Describe how they move and give an example of each.<\/li>\r\n \t
- Which specific type of moveable joint do you think your knee joint is? Explain your reasoning.<\/li>\r\n \t
- Explain the difference between cartilage in a cartilaginous joint and cartilage in a synovial joint.<\/li>\r\n \t
- Why are fibrous joints immovable?<\/li>\r\n \t
- What is the function of synovial fluid?<\/li>\r\n<\/ol>\r\n<\/div>\r\n<\/div>\r\n
\r\n11.6 Explore More<\/span><\/h1>\r\n<\/header>\r\n\r\n\r\nhttps:\/\/www.youtube.com\/watch?v=IjiKUmfaZr4\r\nWhy do your knuckles pop? - Eleanor Nelsen, TED-Ed, 2015.<\/p>\r\nhttps:\/\/www.youtube.com\/watch?v=FWsBm3hr3B0\r\n
Why haven\u2019t we cured arthritis? - Kaitlyn Sadtler and Heather J. Faust, TED-Ed, 2019.<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n \r\n\r\n<\/div>\r\n
Attributions<\/h2>\r\nFigure 11.6.1<\/strong>\r\n\r\nTags: Sports Gymnastics Fitness Woman Preparation<\/a> by nastya_gepp<\/a> on Pixabay<\/a> is used under the Pixabay License<\/a> (https:\/\/pixabay.com\/de\/service\/license\/).\r\n\r\nFigure 11.6.2<\/strong>\r\n\r\nSynovial_Joints<\/a> by OpenStax College<\/a> on Wikimedia Commons is used under a CC BY 3.0 <\/a>(https:\/\/creativecommons.org\/licenses\/by\/3.0) license.\r\n\r\nFigure 11.6.3<\/strong>\r\n\r\nTypes_of_Synovial_Joints<\/a>\u00a0by OpenStax College<\/a> on Wikimedia Commons is used under a CC BY 3.0 <\/a>(https:\/\/creativecommons.org\/licenses\/by\/3.0) license.\r\nReferences<\/h2>\r\n
Betts, J. G., Young, K.A., Wise, J.A., Johnson, E., Poe, B., Kruse, D.H., Korol, O., Johnson, J.E., Womble, M., DeSaix, P. (2013, June 19). Figure\u00a0<\/span><\/span>9.8<\/span><\/span>\u00a0<\/span>Synovial joints<\/span><\/span> [digital image].\u00a0 In Anatomy and Physiology<\/em> (Section 9.4). OpenStax. https:\/\/openstax.org\/books\/anatomy-and-physiology\/pages\/9-4-synovial-joints<\/p>\r\nBetts, J. G., Young, K.A., Wise, J.A., Johnson, E., Poe, B., Kruse, D.H., Korol, O., Johnson, J.E., Womble, M., DeSaix, P. (2013, June 19). Figure 9.10 Types of synovial joints [digital image].\u00a0 In Anatomy and Physiology<\/em> (Section 9.4). OpenStax. https:\/\/openstax.org\/books\/anatomy-and-physiology\/pages\/9-4-synovial-joints<\/p>\r\nMayo Clinic Staff. (n.d.). Osteoarthritis [online article]. MayoClinic.org. https:\/\/www.mayoclinic.org\/diseases-conditions\/osteoarthritis\/symptoms-causes\/syc-20351925<\/p>\r\n
TED-Ed. (2015, May 5). Why do your knuckles pop? - Eleanor Nelsen. YouTube. https:\/\/www.youtube.com\/watch?v=IjiKUmfaZr4<\/p>\r\n
TED-Ed. (2019, November 7). Why haven\u2019t we cured arthritis? - Kaitlyn Sadtler and Heather J. Faust. YouTube. https:\/\/www.youtube.com\/watch?v=FWsBm3hr3B0<\/p>\r\n ","rendered":"
<\/p>\nFigure 11.6.1 That’s quite a stretch!<\/em><\/figcaption><\/figure>\n\nDouble Jointed?<\/h1>\n<\/div>\n
Is this woman double jointed? No, there is actually no such thing \u2014 at least as far as humans are concerned. However, some people, like the woman pictured in Figure 11.6.1, are much more flexible than others, generally because they have looser ligaments. Physicians call this condition joint hypermobility. Regardless of what it\u2019s called, the feats of people with highly mobile joints can be quite impressive.<\/p>\n
\nWhat Are Joints?<\/h1>\n<\/div>\n
Joints<\/strong>\u00a0<\/a>are locations at which\u00a0bones\u00a0of the skeleton connect with one another. A joint is also called an articulation. The majority of joints are structured in such a way that they allow movement. However, not all joints allow movement. Of joints that\u00a0do<\/em>\u00a0allow movement, the extent and direction of the movements they allow also vary.<\/p>\n\nClassification\u00a0of Joints<\/h1>\n<\/div>\n
Joints can be classified structurally or functionally. The structural\u00a0classification\u00a0of joints depends on the manner in which the\u00a0bones\u00a0connect to each other. The functional classification of joints depends on the nature of the movement the joints allow. There is significant overlap between the two types of classifications, because function depends largely on structure.<\/p>\n
Structural Classification of Joints<\/h2>\n
The structural classification of joints is based on the type of tissue that binds the\u00a0bones\u00a0to each other at the joint. There are three types of joints in the structural classification: fibrous, cartilaginous, and synovial joints.<\/p>\n
\n- Fibrous joints<\/a><\/strong> are joints in which bones are joined by dense connective tissue that is rich in collagen fibres. These joints are also called sutures. The joints between bones of the cranium are fibrous joints.<\/li>\n
- Cartilaginous joints<\/a><\/strong>\u00a0are joints in which bones are joined by cartilage. The joints between most of the vertebrae in the spine are cartilaginous joints.<\/li>\n
- Synovial joints<\/a><\/strong> are characterized by a fluid-filled space (called a synovial cavity) between the bones of the joints. You can see a drawing of a typical synovial joint in Figure 11.6.2. The cavity is enclosed by a membrane and filled with a fluid (called synovial fluid) that provides extra cushioning to the ends of the bones. Cartilage covers the articulating surfaces of the two bones, but the bones are actually held together by ligaments. The knee is a synovial joint.<\/li>\n<\/ol>\n
Figure 11.6.2 A typical synovial joint is represented by this diagram.<\/em><\/figcaption><\/figure>\nFunctional Classification of Joints<\/h2>\n
The functional classification of joints is based on the type and degree of movement that they allow. There are three types of joints in the functional classification: immovable, partly movable, and movable joints.<\/p>\n
\n- Immovable joints<\/a><\/strong>\u00a0allow little or no movement at the joint. Most immovable joints are fibrous joints. Besides the bones of the cranium, immovable joints include joints between the tibia and fibula in the lower leg, and between the radius and ulna in the lower arm.<\/li>\n
- Partly movable joints<\/a><\/strong>\u00a0permit slight movement. Most partly movable joints are cartilaginous joints. Besides the joints between vertebrae, they include the joints between the ribs and sternum (breast bone).<\/li>\n
- Movable joints<\/a><\/strong>\u00a0allow bones to move freely. All movable joints are synovial joints. Besides the knee, they include the shoulder, hip, and elbow. Movable joints are the most common type of joints in the body.<\/li>\n<\/ol>\n
Types of Movable Joints<\/h2>\n
Movable joints can be classified further according to the type of movement they allow. There are six classes of movable joints: pivot, hinge, saddle, plane, condyloid, and ball-and-socket joints. An example of each class \u2014 as well as the type of movement it allows \u2014 is shown in Figure 11.6.3.<\/p>\n
\nFigure 11.6.3 This diagram shows the six classes of movable joints in the human body. All of these joints are synovial joints.<\/em><\/figcaption><\/figure>\n<\/div>\n\n- A\u00a0ball-and-socket joint<\/a><\/strong> allows the greatest range of movement of any movable joint. It allows forward and backward motion, as well as upward and downward movement. It also allows rotation in a circle. The hip and shoulder are the only two ball-and-socket joints in the human body.<\/li>\n
- A\u00a0pivot joint<\/a><\/strong>\u00a0allows one bone to rotate around another. An example of a pivot joint is the joint between the first two vertebrae in the spine. This joint allows the head to rotate from left to right and back again.<\/li>\n
- A\u00a0hinge joint<\/a><\/strong>\u00a0allows back and forth movement like the hinge of a door. An example of a hinge joint is the elbow. This joint allows the arm to bend back and forth.<\/li>\n
- A\u00a0saddle joint<\/a><\/strong>\u00a0allows two different types of movement. An example of a saddle joint is the joint between the first metacarpal bone in the hand and one of the carpal bones in the wrist. This joint allows the thumb to move toward and away from the index finger, and also to cross over the palm toward the little finger.<\/li>\n
- A\u00a0plane joint<\/a><\/strong>\u00a0(also called a gliding joint) allows two bones\u00a0to\u00a0glide over one another. The joints between the tarsals in the ankles and between the carpals in the wrists are mainly gliding joints. In the wrist, this type of joint allows the hand to bend upward at the wrist, and also to wave from side to side while the lower arm is held steady.<\/li>\n
- A\u00a0condyloid joint<\/a><\/strong>\u00a0is one in which an oval-shaped head on one bone moves in an elliptical cavity in another bone, allowing movement in all directions, except rotation around an axis. The joint between the radius in the lower arm and carpal bones of the wrist is a condyloid joint, as is the joint at the\u00a0base\u00a0of the index finger.<\/li>\n<\/ul>\n\n
Feature: My\u00a0Human Body<\/h1>\n<\/div>\n
Of all the parts of the\u00a0skeletal system, the joints are generally the most fragile and subject to damage. If the cartilage that cushions bones at joints wears away, it does not grow back. Eventually, all of the cartilage may wear away. This causes osteoarthritis<\/a>, which can be both painful and debilitating. In serious cases of osteoarthritis<\/a>, people may lose the ability to climb stairs, walk long distances, perform routine daily activities, or participate in activities they love, such as gardening or playing sports. If you protect your joints, you can reduce your chances of joint damage, pain, and disability. If you already have joint damage, it is equally important to protect your joints and limit further damage. Follow these five tips:<\/p>\n\n- Maintain a normal, healthy<\/strong>\u00a0<\/strong>weight.<\/strong>\u00a0The\u00a0more you weigh, the more force you exert on your joints. When you walk, each knee has to bear a force equal to as much as\u00a0six times<\/em>\u00a0your body\u00a0weight. If a person weighs 200 pounds, each knee bears more than half a ton of weight with every step. Seven in ten knee replacement surgeries for osteoarthritis can be attributed to\u00a0obesity.<\/li>\n
- Avoid too much high-impact<\/strong>\u00a0<\/strong>exercise.<\/strong>\u00a0Examples of high-impact activities include volleyball, basketball, and tennis. These activities generally involve running or jumping on hard surfaces, which puts tremendous stress on weight-bearing joints, especially the knees. Replace some or all of your high-impact activities with low-impact activities, such as biking, swimming, yoga, or lifting light weights.<\/li>\n
- Reduce your risk of injury.<\/strong>\u00a0Don\u2019t be a weekend warrior, sitting at a desk all week and then crowding all your physical activity into two days. Get involved in a regular, daily\u00a0exercise\u00a0routine that keeps your body fit and your\u00a0muscles\u00a0toned. Building up muscles will make your joints more stable, allowing stress to spread across them. Be sure to do some stretching every day to keep the muscles around joints flexible and less prone to injury.<\/li>\n
- Distribute work over your body, and use your largest, strongest joints.<\/strong>\u00a0Use your shoulder, elbow, and wrist to lift heavy objects \u2014 not just your fingers. Hold small items in the palm of your hand, rather than by the fingers. Carry heavy items in a backpack, rather than in your hands. Hold weighty objects close to your body, instead of at arms\u2019 length. Lift with your hips and knees, not your back.<\/li>\n
- Respect pain.<\/strong>\u00a0If it hurts, stop doing it. Take a break from the activity \u2014 at least until the pain stops. Try to use joints only to the point of mild fatigue, not pain.<\/li>\n<\/ol>\n\n\n
\n11.6 Summary<\/span><\/h1>\n<\/header>\n\n\n- Joints<\/a>\u00a0are\u00a0spots\u00a0at which bones<\/a>\u00a0of the skeleton connect with one another. A joint is also called an articulation.<\/li>\n
- Joints can be classified structurally or functionally, and there is significant overlap between the two types of classifications.<\/li>\n
- The structural classification of joints depends on the type of tissue that binds the bones to each other at the joint. There are three types of joints in the structural classification: fibrous<\/a>, cartilaginous<\/a>, and synovial joints<\/a>.<\/li>\n
- The functional classification of joints is based on the type and degree of movement that they allow. There are three types of joints in the functional classification: immovable<\/a>, partly movable<\/a>, and movable joints<\/a>.<\/li>\n
- Movable joints can be classified further according to the type of movement they allow. There are six classes of movable joints: pivot<\/a>, hinge<\/a>, saddle<\/a>, plane<\/a>, condyloid<\/a>, and ball-and-socket joints<\/a>.<\/li>\n<\/ul>\n<\/div>\n<\/div>\n\n
\n11.6 Review Questions<\/span><\/h1>\n<\/header>\n\n\n- What are joints?<\/li>\n
- What are two ways that joints are commonly classified?<\/li>\n
- \n\n
Classification\u00a0of Joints<\/h1>\r\n<\/div>\r\nJoints can be classified structurally or functionally. The structural\u00a0classification\u00a0of joints depends on the manner in which the\u00a0bones\u00a0connect to each other. The functional classification of joints depends on the nature of the movement the joints allow. There is significant overlap between the two types of classifications, because function depends largely on structure.\r\nStructural Classification of Joints<\/h2>\r\nThe structural classification of joints is based on the type of tissue that binds the\u00a0bones\u00a0to each other at the joint. There are three types of joints in the structural classification: fibrous, cartilaginous, and synovial joints.\r\n\r\n \t- [pb_glossary id=\"4084\"]Fibrous joints[\/pb_glossary]<\/strong> are joints in which bones are joined by dense connective tissue that is rich in collagen fibres. These joints are also called sutures. The joints between bones of the cranium are fibrous joints.<\/li>\r\n \t
- [pb_glossary id=\"4085\"]Cartilaginous joints[\/pb_glossary]<\/strong>\u00a0are joints in which bones are joined by cartilage. The joints between most of the vertebrae in the spine are cartilaginous joints.<\/li>\r\n \t
- [pb_glossary id=\"4086\"]Synovial joints[\/pb_glossary]<\/strong> are characterized by a fluid-filled space (called a synovial cavity) between the bones of the joints. You can see a drawing of a typical synovial joint in Figure 11.6.2. The cavity is enclosed by a membrane and filled with a fluid (called synovial fluid) that provides extra cushioning to the ends of the bones. Cartilage covers the articulating surfaces of the two bones, but the bones are actually held together by ligaments. The knee is a synovial joint.<\/li>\r\n<\/ol>\r\n[caption id=\"attachment_4087\" align=\"aligncenter\" width=\"483\"] Figure 11.6.2 A typical synovial joint is represented by this diagram.<\/em>[\/caption]\r\n
Functional Classification of Joints<\/h2>\r\nThe functional classification of joints is based on the type and degree of movement that they allow. There are three types of joints in the functional classification: immovable, partly movable, and movable joints.\r\n\r\n \t- [pb_glossary id=\"4088\"]Immovable joints[\/pb_glossary]<\/strong>\u00a0allow little or no movement at the joint. Most immovable joints are fibrous joints. Besides the bones of the cranium, immovable joints include joints between the tibia and fibula in the lower leg, and between the radius and ulna in the lower arm.<\/li>\r\n \t
- [pb_glossary id=\"4090\"]Partly movable joints[\/pb_glossary]<\/strong>\u00a0permit slight movement. Most partly movable joints are cartilaginous joints. Besides the joints between vertebrae, they include the joints between the ribs and sternum (breast bone).<\/li>\r\n \t
- [pb_glossary id=\"5641\"]Movable joints[\/pb_glossary]<\/strong>\u00a0allow bones to move freely. All movable joints are synovial joints. Besides the knee, they include the shoulder, hip, and elbow. Movable joints are the most common type of joints in the body.<\/li>\r\n<\/ol>\r\n
Types of Movable Joints<\/h2>\r\nMovable joints can be classified further according to the type of movement they allow. There are six classes of movable joints: pivot, hinge, saddle, plane, condyloid, and ball-and-socket joints. An example of each class \u2014 as well as the type of movement it allows \u2014 is shown in Figure 11.6.3.\r\n\r\n\r\n[caption id=\"attachment_4099\" align=\"aligncenter\" width=\"985\"] Figure 11.6.3 This diagram shows the six classes of movable joints in the human body. All of these joints are synovial joints.<\/em>[\/caption]\r\n\r\n<\/div>\r\n\r\n \t- A\u00a0[pb_glossary id=\"4093\"]ball-and-socket joint[\/pb_glossary]<\/strong> allows the greatest range of movement of any movable joint. It allows forward and backward motion, as well as upward and downward movement. It also allows rotation in a circle. The hip and shoulder are the only two ball-and-socket joints in the human body.<\/li>\r\n \t
- A\u00a0[pb_glossary id=\"4094\"]pivot joint[\/pb_glossary]<\/strong>\u00a0allows one bone to rotate around another. An example of a pivot joint is the joint between the first two vertebrae in the spine. This joint allows the head to rotate from left to right and back again.<\/li>\r\n \t
- A\u00a0[pb_glossary id=\"4096\"]hinge joint[\/pb_glossary]<\/strong>\u00a0allows back and forth movement like the hinge of a door. An example of a hinge joint is the elbow. This joint allows the arm to bend back and forth.<\/li>\r\n \t
- A\u00a0[pb_glossary id=\"4098\"]saddle joint[\/pb_glossary]<\/strong>\u00a0allows two different types of movement. An example of a saddle joint is the joint between the first metacarpal bone in the hand and one of the carpal bones in the wrist. This joint allows the thumb to move toward and away from the index finger, and also to cross over the palm toward the little finger.<\/li>\r\n \t
- A\u00a0[pb_glossary id=\"4100\"]plane joint[\/pb_glossary]<\/strong>\u00a0(also called a gliding joint) allows two bones\u00a0to\u00a0glide over one another. The joints between the tarsals in the ankles and between the carpals in the wrists are mainly gliding joints. In the wrist, this type of joint allows the hand to bend upward at the wrist, and also to wave from side to side while the lower arm is held steady.<\/li>\r\n \t
- A\u00a0[pb_glossary id=\"5483\"]condyloid joint[\/pb_glossary]<\/strong>\u00a0is one in which an oval-shaped head on one bone moves in an elliptical cavity in another bone, allowing movement in all directions, except rotation around an axis. The joint between the radius in the lower arm and carpal bones of the wrist is a condyloid joint, as is the joint at the\u00a0base\u00a0of the index finger.<\/li>\r\n<\/ul>\r\n\r\n
Feature: My\u00a0Human Body<\/h1>\r\n<\/div>\r\nOf all the parts of the\u00a0skeletal system, the joints are generally the most fragile and subject to damage. If the cartilage that cushions bones at joints wears away, it does not grow back. Eventually, all of the cartilage may wear away. This causes [pb_glossary id=\"4102\"]osteoarthritis[\/pb_glossary], which can be both painful and debilitating. In serious cases of osteoarthritis<\/a>, people may lose the ability to climb stairs, walk long distances, perform routine daily activities, or participate in activities they love, such as gardening or playing sports. If you protect your joints, you can reduce your chances of joint damage, pain, and disability. If you already have joint damage, it is equally important to protect your joints and limit further damage. Follow these five tips:\r\n\r\n \t- Maintain a normal, healthy<\/strong>\u00a0<\/strong>weight.<\/strong>\u00a0The\u00a0more you weigh, the more force you exert on your joints. When you walk, each knee has to bear a force equal to as much as\u00a0six times<\/em>\u00a0your body\u00a0weight. If a person weighs 200 pounds, each knee bears more than half a ton of weight with every step. Seven in ten knee replacement surgeries for osteoarthritis can be attributed to\u00a0obesity.<\/li>\r\n \t
- Avoid too much high-impact<\/strong>\u00a0<\/strong>exercise.<\/strong>\u00a0Examples of high-impact activities include volleyball, basketball, and tennis. These activities generally involve running or jumping on hard surfaces, which puts tremendous stress on weight-bearing joints, especially the knees. Replace some or all of your high-impact activities with low-impact activities, such as biking, swimming, yoga, or lifting light weights.<\/li>\r\n \t
- Reduce your risk of injury.<\/strong>\u00a0Don\u2019t be a weekend warrior, sitting at a desk all week and then crowding all your physical activity into two days. Get involved in a regular, daily\u00a0exercise\u00a0routine that keeps your body fit and your\u00a0muscles\u00a0toned. Building up muscles will make your joints more stable, allowing stress to spread across them. Be sure to do some stretching every day to keep the muscles around joints flexible and less prone to injury.<\/li>\r\n \t
- Distribute work over your body, and use your largest, strongest joints.<\/strong>\u00a0Use your shoulder, elbow, and wrist to lift heavy objects \u2014 not just your fingers. Hold small items in the palm of your hand, rather than by the fingers. Carry heavy items in a backpack, rather than in your hands. Hold weighty objects close to your body, instead of at arms\u2019 length. Lift with your hips and knees, not your back.<\/li>\r\n \t
- Respect pain.<\/strong>\u00a0If it hurts, stop doing it. Take a break from the activity \u2014 at least until the pain stops. Try to use joints only to the point of mild fatigue, not pain.<\/li>\r\n<\/ol>\r\n\r\n
\r\n11.6 Summary<\/span><\/h1>\r\n<\/header>\r\n\r\n\r\n \t- [pb_glossary id=\"3949\"]Joints[\/pb_glossary]\u00a0are\u00a0spots\u00a0at which [pb_glossary id=\"5913\"]bones[\/pb_glossary]\u00a0of the skeleton connect with one another. A joint is also called an articulation.<\/li>\r\n \t
- Joints can be classified structurally or functionally, and there is significant overlap between the two types of classifications.<\/li>\r\n \t
- The structural classification of joints depends on the type of tissue that binds the bones to each other at the joint. There are three types of joints in the structural classification: [pb_glossary id=\"4084\"]fibrous[\/pb_glossary], [pb_glossary id=\"4085\"]cartilaginous[\/pb_glossary], and [pb_glossary id=\"4086\"]synovial joints[\/pb_glossary].<\/li>\r\n \t
- The functional classification of joints is based on the type and degree of movement that they allow. There are three types of joints in the functional classification: [pb_glossary id=\"4088\"]immovable[\/pb_glossary], [pb_glossary id=\"4090\"]partly movable[\/pb_glossary], and [pb_glossary id=\"5641\"]movable joints[\/pb_glossary].<\/li>\r\n \t
- Movable joints can be classified further according to the type of movement they allow. There are six classes of movable joints: [pb_glossary id=\"4094\"]pivot[\/pb_glossary], [pb_glossary id=\"4096\"]hinge[\/pb_glossary], [pb_glossary id=\"4098\"]saddle[\/pb_glossary], [pb_glossary id=\"4100\"]plane[\/pb_glossary], [pb_glossary id=\"5483\"]condyloid[\/pb_glossary], and [pb_glossary id=\"4093\"]ball-and-socket joints[\/pb_glossary].<\/li>\r\n<\/ul>\r\n<\/div>\r\n<\/div>\r\n
\r\n11.6 Review Questions<\/span><\/h1>\r\n<\/header>\r\n\r\n\r\n \t- What are joints?<\/li>\r\n \t
- What are two ways that joints are commonly classified?<\/li>\r\n \t
- [h5p id=\"597\"]<\/li>\r\n \t
- How are joints classified structurally?<\/li>\r\n \t
- Describe the functional classification of joints.<\/li>\r\n \t
- How are movable joints classified?<\/li>\r\n \t
- Name the six classes of movable joints. Describe how they move and give an example of each.<\/li>\r\n \t
- Which specific type of moveable joint do you think your knee joint is? Explain your reasoning.<\/li>\r\n \t
- Explain the difference between cartilage in a cartilaginous joint and cartilage in a synovial joint.<\/li>\r\n \t
- Why are fibrous joints immovable?<\/li>\r\n \t
- What is the function of synovial fluid?<\/li>\r\n<\/ol>\r\n<\/div>\r\n<\/div>\r\n
\r\n11.6 Explore More<\/span><\/h1>\r\n<\/header>\r\n\r\n\r\nhttps:\/\/www.youtube.com\/watch?v=IjiKUmfaZr4\r\nWhy do your knuckles pop? - Eleanor Nelsen, TED-Ed, 2015.<\/p>\r\nhttps:\/\/www.youtube.com\/watch?v=FWsBm3hr3B0\r\n
Why haven\u2019t we cured arthritis? - Kaitlyn Sadtler and Heather J. Faust, TED-Ed, 2019.<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n \r\n\r\n<\/div>\r\n
Attributions<\/h2>\r\nFigure 11.6.1<\/strong>\r\n\r\nTags: Sports Gymnastics Fitness Woman Preparation<\/a> by nastya_gepp<\/a> on Pixabay<\/a> is used under the Pixabay License<\/a> (https:\/\/pixabay.com\/de\/service\/license\/).\r\n\r\nFigure 11.6.2<\/strong>\r\n\r\nSynovial_Joints<\/a> by OpenStax College<\/a> on Wikimedia Commons is used under a CC BY 3.0 <\/a>(https:\/\/creativecommons.org\/licenses\/by\/3.0) license.\r\n\r\nFigure 11.6.3<\/strong>\r\n\r\nTypes_of_Synovial_Joints<\/a>\u00a0by OpenStax College<\/a> on Wikimedia Commons is used under a CC BY 3.0 <\/a>(https:\/\/creativecommons.org\/licenses\/by\/3.0) license.\r\nReferences<\/h2>\r\n
Betts, J. G., Young, K.A., Wise, J.A., Johnson, E., Poe, B., Kruse, D.H., Korol, O., Johnson, J.E., Womble, M., DeSaix, P. (2013, June 19). Figure\u00a0<\/span><\/span>9.8<\/span><\/span>\u00a0<\/span>Synovial joints<\/span><\/span> [digital image].\u00a0 In Anatomy and Physiology<\/em> (Section 9.4). OpenStax. https:\/\/openstax.org\/books\/anatomy-and-physiology\/pages\/9-4-synovial-joints<\/p>\r\nBetts, J. G., Young, K.A., Wise, J.A., Johnson, E., Poe, B., Kruse, D.H., Korol, O., Johnson, J.E., Womble, M., DeSaix, P. (2013, June 19). Figure 9.10 Types of synovial joints [digital image].\u00a0 In Anatomy and Physiology<\/em> (Section 9.4). OpenStax. https:\/\/openstax.org\/books\/anatomy-and-physiology\/pages\/9-4-synovial-joints<\/p>\r\nMayo Clinic Staff. (n.d.). Osteoarthritis [online article]. MayoClinic.org. https:\/\/www.mayoclinic.org\/diseases-conditions\/osteoarthritis\/symptoms-causes\/syc-20351925<\/p>\r\n
TED-Ed. (2015, May 5). Why do your knuckles pop? - Eleanor Nelsen. YouTube. https:\/\/www.youtube.com\/watch?v=IjiKUmfaZr4<\/p>\r\n
TED-Ed. (2019, November 7). Why haven\u2019t we cured arthritis? - Kaitlyn Sadtler and Heather J. Faust. YouTube. https:\/\/www.youtube.com\/watch?v=FWsBm3hr3B0<\/p>\r\n ","rendered":"
<\/p>\nFigure 11.6.1 That’s quite a stretch!<\/em><\/figcaption><\/figure>\n\nDouble Jointed?<\/h1>\n<\/div>\n
Is this woman double jointed? No, there is actually no such thing \u2014 at least as far as humans are concerned. However, some people, like the woman pictured in Figure 11.6.1, are much more flexible than others, generally because they have looser ligaments. Physicians call this condition joint hypermobility. Regardless of what it\u2019s called, the feats of people with highly mobile joints can be quite impressive.<\/p>\n
\nWhat Are Joints?<\/h1>\n<\/div>\n
Joints<\/strong>\u00a0<\/a>are locations at which\u00a0bones\u00a0of the skeleton connect with one another. A joint is also called an articulation. The majority of joints are structured in such a way that they allow movement. However, not all joints allow movement. Of joints that\u00a0do<\/em>\u00a0allow movement, the extent and direction of the movements they allow also vary.<\/p>\n\nClassification\u00a0of Joints<\/h1>\n<\/div>\n
Joints can be classified structurally or functionally. The structural\u00a0classification\u00a0of joints depends on the manner in which the\u00a0bones\u00a0connect to each other. The functional classification of joints depends on the nature of the movement the joints allow. There is significant overlap between the two types of classifications, because function depends largely on structure.<\/p>\n
Structural Classification of Joints<\/h2>\n
The structural classification of joints is based on the type of tissue that binds the\u00a0bones\u00a0to each other at the joint. There are three types of joints in the structural classification: fibrous, cartilaginous, and synovial joints.<\/p>\n
\n- Fibrous joints<\/a><\/strong> are joints in which bones are joined by dense connective tissue that is rich in collagen fibres. These joints are also called sutures. The joints between bones of the cranium are fibrous joints.<\/li>\n
- Cartilaginous joints<\/a><\/strong>\u00a0are joints in which bones are joined by cartilage. The joints between most of the vertebrae in the spine are cartilaginous joints.<\/li>\n
- Synovial joints<\/a><\/strong> are characterized by a fluid-filled space (called a synovial cavity) between the bones of the joints. You can see a drawing of a typical synovial joint in Figure 11.6.2. The cavity is enclosed by a membrane and filled with a fluid (called synovial fluid) that provides extra cushioning to the ends of the bones. Cartilage covers the articulating surfaces of the two bones, but the bones are actually held together by ligaments. The knee is a synovial joint.<\/li>\n<\/ol>\n
Figure 11.6.2 A typical synovial joint is represented by this diagram.<\/em><\/figcaption><\/figure>\nFunctional Classification of Joints<\/h2>\n
The functional classification of joints is based on the type and degree of movement that they allow. There are three types of joints in the functional classification: immovable, partly movable, and movable joints.<\/p>\n
\n- Immovable joints<\/a><\/strong>\u00a0allow little or no movement at the joint. Most immovable joints are fibrous joints. Besides the bones of the cranium, immovable joints include joints between the tibia and fibula in the lower leg, and between the radius and ulna in the lower arm.<\/li>\n
- Partly movable joints<\/a><\/strong>\u00a0permit slight movement. Most partly movable joints are cartilaginous joints. Besides the joints between vertebrae, they include the joints between the ribs and sternum (breast bone).<\/li>\n
- Movable joints<\/a><\/strong>\u00a0allow bones to move freely. All movable joints are synovial joints. Besides the knee, they include the shoulder, hip, and elbow. Movable joints are the most common type of joints in the body.<\/li>\n<\/ol>\n
Types of Movable Joints<\/h2>\n
Movable joints can be classified further according to the type of movement they allow. There are six classes of movable joints: pivot, hinge, saddle, plane, condyloid, and ball-and-socket joints. An example of each class \u2014 as well as the type of movement it allows \u2014 is shown in Figure 11.6.3.<\/p>\n
\nFigure 11.6.3 This diagram shows the six classes of movable joints in the human body. All of these joints are synovial joints.<\/em><\/figcaption><\/figure>\n<\/div>\n\n- A\u00a0ball-and-socket joint<\/a><\/strong> allows the greatest range of movement of any movable joint. It allows forward and backward motion, as well as upward and downward movement. It also allows rotation in a circle. The hip and shoulder are the only two ball-and-socket joints in the human body.<\/li>\n
- A\u00a0pivot joint<\/a><\/strong>\u00a0allows one bone to rotate around another. An example of a pivot joint is the joint between the first two vertebrae in the spine. This joint allows the head to rotate from left to right and back again.<\/li>\n
- A\u00a0hinge joint<\/a><\/strong>\u00a0allows back and forth movement like the hinge of a door. An example of a hinge joint is the elbow. This joint allows the arm to bend back and forth.<\/li>\n
- A\u00a0saddle joint<\/a><\/strong>\u00a0allows two different types of movement. An example of a saddle joint is the joint between the first metacarpal bone in the hand and one of the carpal bones in the wrist. This joint allows the thumb to move toward and away from the index finger, and also to cross over the palm toward the little finger.<\/li>\n
- A\u00a0plane joint<\/a><\/strong>\u00a0(also called a gliding joint) allows two bones\u00a0to\u00a0glide over one another. The joints between the tarsals in the ankles and between the carpals in the wrists are mainly gliding joints. In the wrist, this type of joint allows the hand to bend upward at the wrist, and also to wave from side to side while the lower arm is held steady.<\/li>\n
- A\u00a0condyloid joint<\/a><\/strong>\u00a0is one in which an oval-shaped head on one bone moves in an elliptical cavity in another bone, allowing movement in all directions, except rotation around an axis. The joint between the radius in the lower arm and carpal bones of the wrist is a condyloid joint, as is the joint at the\u00a0base\u00a0of the index finger.<\/li>\n<\/ul>\n\n
Feature: My\u00a0Human Body<\/h1>\n<\/div>\n
Of all the parts of the\u00a0skeletal system, the joints are generally the most fragile and subject to damage. If the cartilage that cushions bones at joints wears away, it does not grow back. Eventually, all of the cartilage may wear away. This causes osteoarthritis<\/a>, which can be both painful and debilitating. In serious cases of osteoarthritis<\/a>, people may lose the ability to climb stairs, walk long distances, perform routine daily activities, or participate in activities they love, such as gardening or playing sports. If you protect your joints, you can reduce your chances of joint damage, pain, and disability. If you already have joint damage, it is equally important to protect your joints and limit further damage. Follow these five tips:<\/p>\n\n- Maintain a normal, healthy<\/strong>\u00a0<\/strong>weight.<\/strong>\u00a0The\u00a0more you weigh, the more force you exert on your joints. When you walk, each knee has to bear a force equal to as much as\u00a0six times<\/em>\u00a0your body\u00a0weight. If a person weighs 200 pounds, each knee bears more than half a ton of weight with every step. Seven in ten knee replacement surgeries for osteoarthritis can be attributed to\u00a0obesity.<\/li>\n
- Avoid too much high-impact<\/strong>\u00a0<\/strong>exercise.<\/strong>\u00a0Examples of high-impact activities include volleyball, basketball, and tennis. These activities generally involve running or jumping on hard surfaces, which puts tremendous stress on weight-bearing joints, especially the knees. Replace some or all of your high-impact activities with low-impact activities, such as biking, swimming, yoga, or lifting light weights.<\/li>\n
- Reduce your risk of injury.<\/strong>\u00a0Don\u2019t be a weekend warrior, sitting at a desk all week and then crowding all your physical activity into two days. Get involved in a regular, daily\u00a0exercise\u00a0routine that keeps your body fit and your\u00a0muscles\u00a0toned. Building up muscles will make your joints more stable, allowing stress to spread across them. Be sure to do some stretching every day to keep the muscles around joints flexible and less prone to injury.<\/li>\n
- Distribute work over your body, and use your largest, strongest joints.<\/strong>\u00a0Use your shoulder, elbow, and wrist to lift heavy objects \u2014 not just your fingers. Hold small items in the palm of your hand, rather than by the fingers. Carry heavy items in a backpack, rather than in your hands. Hold weighty objects close to your body, instead of at arms\u2019 length. Lift with your hips and knees, not your back.<\/li>\n
- Respect pain.<\/strong>\u00a0If it hurts, stop doing it. Take a break from the activity \u2014 at least until the pain stops. Try to use joints only to the point of mild fatigue, not pain.<\/li>\n<\/ol>\n\n\n
\n11.6 Summary<\/span><\/h1>\n<\/header>\n\n\n- Joints<\/a>\u00a0are\u00a0spots\u00a0at which bones<\/a>\u00a0of the skeleton connect with one another. A joint is also called an articulation.<\/li>\n
- Joints can be classified structurally or functionally, and there is significant overlap between the two types of classifications.<\/li>\n
- The structural classification of joints depends on the type of tissue that binds the bones to each other at the joint. There are three types of joints in the structural classification: fibrous<\/a>, cartilaginous<\/a>, and synovial joints<\/a>.<\/li>\n
- The functional classification of joints is based on the type and degree of movement that they allow. There are three types of joints in the functional classification: immovable<\/a>, partly movable<\/a>, and movable joints<\/a>.<\/li>\n
- Movable joints can be classified further according to the type of movement they allow. There are six classes of movable joints: pivot<\/a>, hinge<\/a>, saddle<\/a>, plane<\/a>, condyloid<\/a>, and ball-and-socket joints<\/a>.<\/li>\n<\/ul>\n<\/div>\n<\/div>\n\n
\n11.6 Review Questions<\/span><\/h1>\n<\/header>\n\n\n- What are joints?<\/li>\n
- What are two ways that joints are commonly classified?<\/li>\n
- \n\n
- \r\n \t
- [pb_glossary id=\"4084\"]Fibrous joints[\/pb_glossary]<\/strong> are joints in which bones are joined by dense connective tissue that is rich in collagen fibres. These joints are also called sutures. The joints between bones of the cranium are fibrous joints.<\/li>\r\n \t
- [pb_glossary id=\"4085\"]Cartilaginous joints[\/pb_glossary]<\/strong>\u00a0are joints in which bones are joined by cartilage. The joints between most of the vertebrae in the spine are cartilaginous joints.<\/li>\r\n \t
- [pb_glossary id=\"4086\"]Synovial joints[\/pb_glossary]<\/strong> are characterized by a fluid-filled space (called a synovial cavity) between the bones of the joints. You can see a drawing of a typical synovial joint in Figure 11.6.2. The cavity is enclosed by a membrane and filled with a fluid (called synovial fluid) that provides extra cushioning to the ends of the bones. Cartilage covers the articulating surfaces of the two bones, but the bones are actually held together by ligaments. The knee is a synovial joint.<\/li>\r\n<\/ol>\r\n[caption id=\"attachment_4087\" align=\"aligncenter\" width=\"483\"]
Figure 11.6.2 A typical synovial joint is represented by this diagram.<\/em>[\/caption]\r\nFunctional Classification of Joints<\/h2>\r\nThe functional classification of joints is based on the type and degree of movement that they allow. There are three types of joints in the functional classification: immovable, partly movable, and movable joints.\r\n
- \r\n \t
- [pb_glossary id=\"4088\"]Immovable joints[\/pb_glossary]<\/strong>\u00a0allow little or no movement at the joint. Most immovable joints are fibrous joints. Besides the bones of the cranium, immovable joints include joints between the tibia and fibula in the lower leg, and between the radius and ulna in the lower arm.<\/li>\r\n \t
- [pb_glossary id=\"4090\"]Partly movable joints[\/pb_glossary]<\/strong>\u00a0permit slight movement. Most partly movable joints are cartilaginous joints. Besides the joints between vertebrae, they include the joints between the ribs and sternum (breast bone).<\/li>\r\n \t
- [pb_glossary id=\"5641\"]Movable joints[\/pb_glossary]<\/strong>\u00a0allow bones to move freely. All movable joints are synovial joints. Besides the knee, they include the shoulder, hip, and elbow. Movable joints are the most common type of joints in the body.<\/li>\r\n<\/ol>\r\n
Types of Movable Joints<\/h2>\r\nMovable joints can be classified further according to the type of movement they allow. There are six classes of movable joints: pivot, hinge, saddle, plane, condyloid, and ball-and-socket joints. An example of each class \u2014 as well as the type of movement it allows \u2014 is shown in Figure 11.6.3.\r\n
\r\n\r\n[caption id=\"attachment_4099\" align=\"aligncenter\" width=\"985\"] Figure 11.6.3 This diagram shows the six classes of movable joints in the human body. All of these joints are synovial joints.<\/em>[\/caption]\r\n\r\n<\/div>\r\n- \r\n \t
- A\u00a0[pb_glossary id=\"4093\"]ball-and-socket joint[\/pb_glossary]<\/strong> allows the greatest range of movement of any movable joint. It allows forward and backward motion, as well as upward and downward movement. It also allows rotation in a circle. The hip and shoulder are the only two ball-and-socket joints in the human body.<\/li>\r\n \t
- A\u00a0[pb_glossary id=\"4094\"]pivot joint[\/pb_glossary]<\/strong>\u00a0allows one bone to rotate around another. An example of a pivot joint is the joint between the first two vertebrae in the spine. This joint allows the head to rotate from left to right and back again.<\/li>\r\n \t
- A\u00a0[pb_glossary id=\"4096\"]hinge joint[\/pb_glossary]<\/strong>\u00a0allows back and forth movement like the hinge of a door. An example of a hinge joint is the elbow. This joint allows the arm to bend back and forth.<\/li>\r\n \t
- A\u00a0[pb_glossary id=\"4098\"]saddle joint[\/pb_glossary]<\/strong>\u00a0allows two different types of movement. An example of a saddle joint is the joint between the first metacarpal bone in the hand and one of the carpal bones in the wrist. This joint allows the thumb to move toward and away from the index finger, and also to cross over the palm toward the little finger.<\/li>\r\n \t
- A\u00a0[pb_glossary id=\"4100\"]plane joint[\/pb_glossary]<\/strong>\u00a0(also called a gliding joint) allows two bones\u00a0to\u00a0glide over one another. The joints between the tarsals in the ankles and between the carpals in the wrists are mainly gliding joints. In the wrist, this type of joint allows the hand to bend upward at the wrist, and also to wave from side to side while the lower arm is held steady.<\/li>\r\n \t
- A\u00a0[pb_glossary id=\"5483\"]condyloid joint[\/pb_glossary]<\/strong>\u00a0is one in which an oval-shaped head on one bone moves in an elliptical cavity in another bone, allowing movement in all directions, except rotation around an axis. The joint between the radius in the lower arm and carpal bones of the wrist is a condyloid joint, as is the joint at the\u00a0base\u00a0of the index finger.<\/li>\r\n<\/ul>\r\n
\r\nFeature: My\u00a0Human Body<\/h1>\r\n<\/div>\r\nOf all the parts of the\u00a0skeletal system, the joints are generally the most fragile and subject to damage. If the cartilage that cushions bones at joints wears away, it does not grow back. Eventually, all of the cartilage may wear away. This causes [pb_glossary id=\"4102\"]osteoarthritis[\/pb_glossary], which can be both painful and debilitating. In serious cases of osteoarthritis<\/a>, people may lose the ability to climb stairs, walk long distances, perform routine daily activities, or participate in activities they love, such as gardening or playing sports. If you protect your joints, you can reduce your chances of joint damage, pain, and disability. If you already have joint damage, it is equally important to protect your joints and limit further damage. Follow these five tips:\r\n
- \r\n \t
- Maintain a normal, healthy<\/strong>\u00a0<\/strong>weight.<\/strong>\u00a0The\u00a0more you weigh, the more force you exert on your joints. When you walk, each knee has to bear a force equal to as much as\u00a0six times<\/em>\u00a0your body\u00a0weight. If a person weighs 200 pounds, each knee bears more than half a ton of weight with every step. Seven in ten knee replacement surgeries for osteoarthritis can be attributed to\u00a0obesity.<\/li>\r\n \t
- Avoid too much high-impact<\/strong>\u00a0<\/strong>exercise.<\/strong>\u00a0Examples of high-impact activities include volleyball, basketball, and tennis. These activities generally involve running or jumping on hard surfaces, which puts tremendous stress on weight-bearing joints, especially the knees. Replace some or all of your high-impact activities with low-impact activities, such as biking, swimming, yoga, or lifting light weights.<\/li>\r\n \t
- Reduce your risk of injury.<\/strong>\u00a0Don\u2019t be a weekend warrior, sitting at a desk all week and then crowding all your physical activity into two days. Get involved in a regular, daily\u00a0exercise\u00a0routine that keeps your body fit and your\u00a0muscles\u00a0toned. Building up muscles will make your joints more stable, allowing stress to spread across them. Be sure to do some stretching every day to keep the muscles around joints flexible and less prone to injury.<\/li>\r\n \t
- Distribute work over your body, and use your largest, strongest joints.<\/strong>\u00a0Use your shoulder, elbow, and wrist to lift heavy objects \u2014 not just your fingers. Hold small items in the palm of your hand, rather than by the fingers. Carry heavy items in a backpack, rather than in your hands. Hold weighty objects close to your body, instead of at arms\u2019 length. Lift with your hips and knees, not your back.<\/li>\r\n \t
- Respect pain.<\/strong>\u00a0If it hurts, stop doing it. Take a break from the activity \u2014 at least until the pain stops. Try to use joints only to the point of mild fatigue, not pain.<\/li>\r\n<\/ol>\r\n
\r\n\r\n 11.6 Summary<\/span><\/h1>\r\n<\/header>\r\n
\r\n- \r\n \t
- [pb_glossary id=\"3949\"]Joints[\/pb_glossary]\u00a0are\u00a0spots\u00a0at which [pb_glossary id=\"5913\"]bones[\/pb_glossary]\u00a0of the skeleton connect with one another. A joint is also called an articulation.<\/li>\r\n \t
- Joints can be classified structurally or functionally, and there is significant overlap between the two types of classifications.<\/li>\r\n \t
- The structural classification of joints depends on the type of tissue that binds the bones to each other at the joint. There are three types of joints in the structural classification: [pb_glossary id=\"4084\"]fibrous[\/pb_glossary], [pb_glossary id=\"4085\"]cartilaginous[\/pb_glossary], and [pb_glossary id=\"4086\"]synovial joints[\/pb_glossary].<\/li>\r\n \t
- The functional classification of joints is based on the type and degree of movement that they allow. There are three types of joints in the functional classification: [pb_glossary id=\"4088\"]immovable[\/pb_glossary], [pb_glossary id=\"4090\"]partly movable[\/pb_glossary], and [pb_glossary id=\"5641\"]movable joints[\/pb_glossary].<\/li>\r\n \t
- Movable joints can be classified further according to the type of movement they allow. There are six classes of movable joints: [pb_glossary id=\"4094\"]pivot[\/pb_glossary], [pb_glossary id=\"4096\"]hinge[\/pb_glossary], [pb_glossary id=\"4098\"]saddle[\/pb_glossary], [pb_glossary id=\"4100\"]plane[\/pb_glossary], [pb_glossary id=\"5483\"]condyloid[\/pb_glossary], and [pb_glossary id=\"4093\"]ball-and-socket joints[\/pb_glossary].<\/li>\r\n<\/ul>\r\n<\/div>\r\n<\/div>\r\n
\r\n 11.6 Review Questions<\/span><\/h1>\r\n<\/header>\r\n
\r\n- \r\n \t
- What are joints?<\/li>\r\n \t
- What are two ways that joints are commonly classified?<\/li>\r\n \t
- [h5p id=\"597\"]<\/li>\r\n \t
- How are joints classified structurally?<\/li>\r\n \t
- Describe the functional classification of joints.<\/li>\r\n \t
- How are movable joints classified?<\/li>\r\n \t
- Name the six classes of movable joints. Describe how they move and give an example of each.<\/li>\r\n \t
- Which specific type of moveable joint do you think your knee joint is? Explain your reasoning.<\/li>\r\n \t
- Explain the difference between cartilage in a cartilaginous joint and cartilage in a synovial joint.<\/li>\r\n \t
- Why are fibrous joints immovable?<\/li>\r\n \t
- What is the function of synovial fluid?<\/li>\r\n<\/ol>\r\n<\/div>\r\n<\/div>\r\n
\r\n 11.6 Explore More<\/span><\/h1>\r\n<\/header>\r\n
\r\n\r\nhttps:\/\/www.youtube.com\/watch?v=IjiKUmfaZr4\r\nWhy do your knuckles pop? - Eleanor Nelsen, TED-Ed, 2015.<\/p>\r\nhttps:\/\/www.youtube.com\/watch?v=FWsBm3hr3B0\r\n
Why haven\u2019t we cured arthritis? - Kaitlyn Sadtler and Heather J. Faust, TED-Ed, 2019.<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n \r\n\r\n<\/div>\r\n
Attributions<\/h2>\r\nFigure 11.6.1<\/strong>\r\n\r\nTags: Sports Gymnastics Fitness Woman Preparation<\/a> by nastya_gepp<\/a> on Pixabay<\/a> is used under the Pixabay License<\/a> (https:\/\/pixabay.com\/de\/service\/license\/).\r\n\r\nFigure 11.6.2<\/strong>\r\n\r\nSynovial_Joints<\/a> by OpenStax College<\/a> on Wikimedia Commons is used under a CC BY 3.0 <\/a>(https:\/\/creativecommons.org\/licenses\/by\/3.0) license.\r\n\r\nFigure 11.6.3<\/strong>\r\n\r\nTypes_of_Synovial_Joints<\/a>\u00a0by OpenStax College<\/a> on Wikimedia Commons is used under a CC BY 3.0 <\/a>(https:\/\/creativecommons.org\/licenses\/by\/3.0) license.\r\n
References<\/h2>\r\n
Betts, J. G., Young, K.A., Wise, J.A., Johnson, E., Poe, B., Kruse, D.H., Korol, O., Johnson, J.E., Womble, M., DeSaix, P. (2013, June 19). Figure\u00a0<\/span><\/span>9.8<\/span><\/span>\u00a0<\/span>Synovial joints<\/span><\/span> [digital image].\u00a0 In Anatomy and Physiology<\/em> (Section 9.4). OpenStax. https:\/\/openstax.org\/books\/anatomy-and-physiology\/pages\/9-4-synovial-joints<\/p>\r\n
Betts, J. G., Young, K.A., Wise, J.A., Johnson, E., Poe, B., Kruse, D.H., Korol, O., Johnson, J.E., Womble, M., DeSaix, P. (2013, June 19). Figure 9.10 Types of synovial joints [digital image].\u00a0 In Anatomy and Physiology<\/em> (Section 9.4). OpenStax. https:\/\/openstax.org\/books\/anatomy-and-physiology\/pages\/9-4-synovial-joints<\/p>\r\n
Mayo Clinic Staff. (n.d.). Osteoarthritis [online article]. MayoClinic.org. https:\/\/www.mayoclinic.org\/diseases-conditions\/osteoarthritis\/symptoms-causes\/syc-20351925<\/p>\r\n
TED-Ed. (2015, May 5). Why do your knuckles pop? - Eleanor Nelsen. YouTube. https:\/\/www.youtube.com\/watch?v=IjiKUmfaZr4<\/p>\r\n
TED-Ed. (2019, November 7). Why haven\u2019t we cured arthritis? - Kaitlyn Sadtler and Heather J. Faust. YouTube. https:\/\/www.youtube.com\/watch?v=FWsBm3hr3B0<\/p>\r\n ","rendered":"
<\/p>\n
Figure 11.6.1 That’s quite a stretch!<\/em><\/figcaption><\/figure>\n \nDouble Jointed?<\/h1>\n<\/div>\n
Is this woman double jointed? No, there is actually no such thing \u2014 at least as far as humans are concerned. However, some people, like the woman pictured in Figure 11.6.1, are much more flexible than others, generally because they have looser ligaments. Physicians call this condition joint hypermobility. Regardless of what it\u2019s called, the feats of people with highly mobile joints can be quite impressive.<\/p>\n
\nWhat Are Joints?<\/h1>\n<\/div>\n
Joints<\/strong>\u00a0<\/a>are locations at which\u00a0bones\u00a0of the skeleton connect with one another. A joint is also called an articulation. The majority of joints are structured in such a way that they allow movement. However, not all joints allow movement. Of joints that\u00a0do<\/em>\u00a0allow movement, the extent and direction of the movements they allow also vary.<\/p>\n
\nClassification\u00a0of Joints<\/h1>\n<\/div>\n
Joints can be classified structurally or functionally. The structural\u00a0classification\u00a0of joints depends on the manner in which the\u00a0bones\u00a0connect to each other. The functional classification of joints depends on the nature of the movement the joints allow. There is significant overlap between the two types of classifications, because function depends largely on structure.<\/p>\n
Structural Classification of Joints<\/h2>\n
The structural classification of joints is based on the type of tissue that binds the\u00a0bones\u00a0to each other at the joint. There are three types of joints in the structural classification: fibrous, cartilaginous, and synovial joints.<\/p>\n
- \n
- Fibrous joints<\/a><\/strong> are joints in which bones are joined by dense connective tissue that is rich in collagen fibres. These joints are also called sutures. The joints between bones of the cranium are fibrous joints.<\/li>\n
- Cartilaginous joints<\/a><\/strong>\u00a0are joints in which bones are joined by cartilage. The joints between most of the vertebrae in the spine are cartilaginous joints.<\/li>\n
- Synovial joints<\/a><\/strong> are characterized by a fluid-filled space (called a synovial cavity) between the bones of the joints. You can see a drawing of a typical synovial joint in Figure 11.6.2. The cavity is enclosed by a membrane and filled with a fluid (called synovial fluid) that provides extra cushioning to the ends of the bones. Cartilage covers the articulating surfaces of the two bones, but the bones are actually held together by ligaments. The knee is a synovial joint.<\/li>\n<\/ol>\n
Figure 11.6.2 A typical synovial joint is represented by this diagram.<\/em><\/figcaption><\/figure>\n Functional Classification of Joints<\/h2>\n
The functional classification of joints is based on the type and degree of movement that they allow. There are three types of joints in the functional classification: immovable, partly movable, and movable joints.<\/p>\n
- \n
- Immovable joints<\/a><\/strong>\u00a0allow little or no movement at the joint. Most immovable joints are fibrous joints. Besides the bones of the cranium, immovable joints include joints between the tibia and fibula in the lower leg, and between the radius and ulna in the lower arm.<\/li>\n
- Partly movable joints<\/a><\/strong>\u00a0permit slight movement. Most partly movable joints are cartilaginous joints. Besides the joints between vertebrae, they include the joints between the ribs and sternum (breast bone).<\/li>\n
- Movable joints<\/a><\/strong>\u00a0allow bones to move freely. All movable joints are synovial joints. Besides the knee, they include the shoulder, hip, and elbow. Movable joints are the most common type of joints in the body.<\/li>\n<\/ol>\n
Types of Movable Joints<\/h2>\n
Movable joints can be classified further according to the type of movement they allow. There are six classes of movable joints: pivot, hinge, saddle, plane, condyloid, and ball-and-socket joints. An example of each class \u2014 as well as the type of movement it allows \u2014 is shown in Figure 11.6.3.<\/p>\n
\nFigure 11.6.3 This diagram shows the six classes of movable joints in the human body. All of these joints are synovial joints.<\/em><\/figcaption><\/figure>\n<\/div>\n - \n
- A\u00a0ball-and-socket joint<\/a><\/strong> allows the greatest range of movement of any movable joint. It allows forward and backward motion, as well as upward and downward movement. It also allows rotation in a circle. The hip and shoulder are the only two ball-and-socket joints in the human body.<\/li>\n
- A\u00a0pivot joint<\/a><\/strong>\u00a0allows one bone to rotate around another. An example of a pivot joint is the joint between the first two vertebrae in the spine. This joint allows the head to rotate from left to right and back again.<\/li>\n
- A\u00a0hinge joint<\/a><\/strong>\u00a0allows back and forth movement like the hinge of a door. An example of a hinge joint is the elbow. This joint allows the arm to bend back and forth.<\/li>\n
- A\u00a0saddle joint<\/a><\/strong>\u00a0allows two different types of movement. An example of a saddle joint is the joint between the first metacarpal bone in the hand and one of the carpal bones in the wrist. This joint allows the thumb to move toward and away from the index finger, and also to cross over the palm toward the little finger.<\/li>\n
- A\u00a0plane joint<\/a><\/strong>\u00a0(also called a gliding joint) allows two bones\u00a0to\u00a0glide over one another. The joints between the tarsals in the ankles and between the carpals in the wrists are mainly gliding joints. In the wrist, this type of joint allows the hand to bend upward at the wrist, and also to wave from side to side while the lower arm is held steady.<\/li>\n
- A\u00a0condyloid joint<\/a><\/strong>\u00a0is one in which an oval-shaped head on one bone moves in an elliptical cavity in another bone, allowing movement in all directions, except rotation around an axis. The joint between the radius in the lower arm and carpal bones of the wrist is a condyloid joint, as is the joint at the\u00a0base\u00a0of the index finger.<\/li>\n<\/ul>\n
\nFeature: My\u00a0Human Body<\/h1>\n<\/div>\n
Of all the parts of the\u00a0skeletal system, the joints are generally the most fragile and subject to damage. If the cartilage that cushions bones at joints wears away, it does not grow back. Eventually, all of the cartilage may wear away. This causes osteoarthritis<\/a>, which can be both painful and debilitating. In serious cases of osteoarthritis<\/a>, people may lose the ability to climb stairs, walk long distances, perform routine daily activities, or participate in activities they love, such as gardening or playing sports. If you protect your joints, you can reduce your chances of joint damage, pain, and disability. If you already have joint damage, it is equally important to protect your joints and limit further damage. Follow these five tips:<\/p>\n
- \n
- Maintain a normal, healthy<\/strong>\u00a0<\/strong>weight.<\/strong>\u00a0The\u00a0more you weigh, the more force you exert on your joints. When you walk, each knee has to bear a force equal to as much as\u00a0six times<\/em>\u00a0your body\u00a0weight. If a person weighs 200 pounds, each knee bears more than half a ton of weight with every step. Seven in ten knee replacement surgeries for osteoarthritis can be attributed to\u00a0obesity.<\/li>\n
- Avoid too much high-impact<\/strong>\u00a0<\/strong>exercise.<\/strong>\u00a0Examples of high-impact activities include volleyball, basketball, and tennis. These activities generally involve running or jumping on hard surfaces, which puts tremendous stress on weight-bearing joints, especially the knees. Replace some or all of your high-impact activities with low-impact activities, such as biking, swimming, yoga, or lifting light weights.<\/li>\n
- Reduce your risk of injury.<\/strong>\u00a0Don\u2019t be a weekend warrior, sitting at a desk all week and then crowding all your physical activity into two days. Get involved in a regular, daily\u00a0exercise\u00a0routine that keeps your body fit and your\u00a0muscles\u00a0toned. Building up muscles will make your joints more stable, allowing stress to spread across them. Be sure to do some stretching every day to keep the muscles around joints flexible and less prone to injury.<\/li>\n
- Distribute work over your body, and use your largest, strongest joints.<\/strong>\u00a0Use your shoulder, elbow, and wrist to lift heavy objects \u2014 not just your fingers. Hold small items in the palm of your hand, rather than by the fingers. Carry heavy items in a backpack, rather than in your hands. Hold weighty objects close to your body, instead of at arms\u2019 length. Lift with your hips and knees, not your back.<\/li>\n
- Respect pain.<\/strong>\u00a0If it hurts, stop doing it. Take a break from the activity \u2014 at least until the pain stops. Try to use joints only to the point of mild fatigue, not pain.<\/li>\n<\/ol>\n
\n\n\n 11.6 Summary<\/span><\/h1>\n<\/header>\n
\n- \n
- Joints<\/a>\u00a0are\u00a0spots\u00a0at which bones<\/a>\u00a0of the skeleton connect with one another. A joint is also called an articulation.<\/li>\n
- Joints can be classified structurally or functionally, and there is significant overlap between the two types of classifications.<\/li>\n
- The structural classification of joints depends on the type of tissue that binds the bones to each other at the joint. There are three types of joints in the structural classification: fibrous<\/a>, cartilaginous<\/a>, and synovial joints<\/a>.<\/li>\n
- The functional classification of joints is based on the type and degree of movement that they allow. There are three types of joints in the functional classification: immovable<\/a>, partly movable<\/a>, and movable joints<\/a>.<\/li>\n
- Movable joints can be classified further according to the type of movement they allow. There are six classes of movable joints: pivot<\/a>, hinge<\/a>, saddle<\/a>, plane<\/a>, condyloid<\/a>, and ball-and-socket joints<\/a>.<\/li>\n<\/ul>\n<\/div>\n<\/div>\n
\n\n 11.6 Review Questions<\/span><\/h1>\n<\/header>\n
\n- \n
- What are joints?<\/li>\n
- What are two ways that joints are commonly classified?<\/li>\n
- \n\n
- Avoid too much high-impact<\/strong>\u00a0<\/strong>exercise.<\/strong>\u00a0Examples of high-impact activities include volleyball, basketball, and tennis. These activities generally involve running or jumping on hard surfaces, which puts tremendous stress on weight-bearing joints, especially the knees. Replace some or all of your high-impact activities with low-impact activities, such as biking, swimming, yoga, or lifting light weights.<\/li>\n
- A\u00a0pivot joint<\/a><\/strong>\u00a0allows one bone to rotate around another. An example of a pivot joint is the joint between the first two vertebrae in the spine. This joint allows the head to rotate from left to right and back again.<\/li>\n
- Partly movable joints<\/a><\/strong>\u00a0permit slight movement. Most partly movable joints are cartilaginous joints. Besides the joints between vertebrae, they include the joints between the ribs and sternum (breast bone).<\/li>\n
- Cartilaginous joints<\/a><\/strong>\u00a0are joints in which bones are joined by cartilage. The joints between most of the vertebrae in the spine are cartilaginous joints.<\/li>\n
- Fibrous joints<\/a><\/strong> are joints in which bones are joined by dense connective tissue that is rich in collagen fibres. These joints are also called sutures. The joints between bones of the cranium are fibrous joints.<\/li>\n
- Avoid too much high-impact<\/strong>\u00a0<\/strong>exercise.<\/strong>\u00a0Examples of high-impact activities include volleyball, basketball, and tennis. These activities generally involve running or jumping on hard surfaces, which puts tremendous stress on weight-bearing joints, especially the knees. Replace some or all of your high-impact activities with low-impact activities, such as biking, swimming, yoga, or lifting light weights.<\/li>\r\n \t
- A\u00a0[pb_glossary id=\"4094\"]pivot joint[\/pb_glossary]<\/strong>\u00a0allows one bone to rotate around another. An example of a pivot joint is the joint between the first two vertebrae in the spine. This joint allows the head to rotate from left to right and back again.<\/li>\r\n \t
- [pb_glossary id=\"4090\"]Partly movable joints[\/pb_glossary]<\/strong>\u00a0permit slight movement. Most partly movable joints are cartilaginous joints. Besides the joints between vertebrae, they include the joints between the ribs and sternum (breast bone).<\/li>\r\n \t
- [pb_glossary id=\"4085\"]Cartilaginous joints[\/pb_glossary]<\/strong>\u00a0are joints in which bones are joined by cartilage. The joints between most of the vertebrae in the spine are cartilaginous joints.<\/li>\r\n \t
![Synovial_Joints<\/a> by](\"https:\/\/commons.wikimedia.org\/wiki\/File:907_Synovial_Joints.jpg\"){kind=link}
![Types_of_Synovial_Joints<\/a>\u00a0by](\"https:\/\/commons.wikimedia.org\/wiki\/File:909_Types_of_Synovial_Joints.jpg\"){kind=link}