{"id":73,"date":"2020-05-22T17:06:47","date_gmt":"2020-05-22T17:06:47","guid":{"rendered":"https:\/\/pressbooks.ccconline.org\/acchpr1040\/chapter\/muscular-system\/"},"modified":"2025-03-04T21:13:00","modified_gmt":"2025-03-04T21:13:00","slug":"muscular-system","status":"publish","type":"chapter","link":"https:\/\/pressbooks.ccconline.org\/acchpr1040\/chapter\/muscular-system\/","title":{"raw":"Muscular System","rendered":"Muscular System"},"content":{"raw":"<div class=\"textbox textbox--learning-objectives\"><header class=\"textbox__header\">\n<h2 class=\"textbox__title\"><em>Learning Objectives<\/em><\/h2>\n<\/header>\n<div class=\"textbox__content\">\n<ul>\n \t<li>Examine the anatomy of the muscular system<\/li>\n \t<li>Determine the main functions of the muscular system<\/li>\n \t<li>Differentiate the medical terms of the muscular system and common abbreviations<\/li>\n \t<li>Discover common diseases, disorders, and procedures related to the muscular system<\/li>\n \t<li>Recognize the medical specialties associated with the muscular system<\/li>\n<\/ul>\n<\/div>\n<\/div>\n<h2>Muscular System Word Parts<\/h2>\nClick on prefixes, combining forms, and suffixes to reveal a list of word parts to memorize for the Muscular System.\n\n&nbsp;\n\n[h5p id=\"34\"]\n<h2>Introduction to the Muscular System<\/h2>\nWhen most people think of muscles, they think of the muscles that are visible just under the skin, particularly of the limbs. These are skeletal muscles, so-named because most of them move the skeleton, but there are two additional types of muscles: the smooth muscle and the cardiac muscle. The body has over 600 muscles which contribute significantly to the body's weight.\n<h3>Watch this video:<\/h3>\n<div class=\"textbox shaded\">\n\n[embed]https:\/\/www.youtube.com\/embed\/I80Xx7pA9hQ[\/embed]\n\n<em>Media 7.1 <a href=\"https:\/\/youtu.be\/I80Xx7pA9hQ\">Muscles, Part 2 - Organismal Level: Crash Course A&amp;P #22<\/a> [Online video]. Copyright 2015 by <a href=\"https:\/\/www.youtube.com\/channel\/UCX6b17PVsYBQ0ip5gyeme-Q\">CrashCourse<\/a>.<\/em>\n\n<\/div>\n<h2>Medical Terms Related to the Muscular System<\/h2>\n[h5p id=\"35\"]\n<h2 id=\"fs-id1840923\" style=\"margin-top: 2.14286em; margin-bottom: 1.42857em;\">Anatomy (Structures) of the Muscular System<\/h2>\nMuscle is one of the four primary tissue types of the body, and it is made up of specialized cells called fibers. The body contains three types of muscle tissue: [pb_glossary id=\"575\"]skeletal muscle[\/pb_glossary], [pb_glossary id=\"576\"]cardiac muscle[\/pb_glossary], and [pb_glossary id=\"577\"]smooth muscle[\/pb_glossary] (see <a href=\"#Figure7.1\">Figure 7.1<\/a>). All three muscle tissues have some properties in common; they all exhibit a quality called <strong>excitability<\/strong> as their plasma membranes can change their electrical states (from polarized to depolarized) and send an electrical wave called an action potential along the entire length of the membrane. <strong>Fascia<\/strong> is fibrous connective tissue that encloses muscles.\n<figure id=\"fig-ch10_01_01\">[caption id=\"\" align=\"aligncenter\" width=\"320\"]<img src=\"https:\/\/opentextbc.ca\/anatomyandphysiology\/wp-content\/uploads\/sites\/142\/2016\/03\/414_Skeletal_Smooth_Cardiac-1.jpg\" alt=\"This figure show the micrographs of skeletal muscle, smooth muscle, and cardiac muscle cells.\" width=\"320\" height=\"1068\"> <a id=\"Figure7.1\" href=\"\"><\/a>Figure 7.1 The Three Types of Muscle Tissue. The body contains three types of muscle tissue: (a) skeletal muscle, (b) smooth muscle, and (c) cardiac muscle. (Micrographs provided by the Regents of University of Michigan Medical School \u00a9 2012). From Betts et al., 2013. Licensed under <a href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0<\/a>. <a href=\"#Figure7.1id\">[Image description.]<\/a>[\/caption]\n<h3>Three Types of Muscle Tissues<\/h3>\n<ul>\n \t<li><strong>Skeletal<\/strong> - closely associated with the skeletal system. Also known as striated muscles, they are responsible for voluntary muscle movement, such as swallowing, et cetera.<\/li>\n \t<li><strong>Smooth<\/strong> - mainly associated with the walls of the internal organs. Also known as visceral muscles, they are responsible for involuntary muscle movement, such as breathing, et cetera.<\/li>\n \t<li><strong>Cardiac<\/strong> - heart muscle or myocardium. Its appearance is similar to a skeletal muscle and is responsible for the pumping of blood. It gives the heart beat.<\/li>\n<\/ul>\n<div class=\"textbox textbox--sidebar textbox--key-takeaways\"><\/div>\n<h4>Skeletal Muscle<\/h4>\nSkeletal muscles act not only to produce movement but also to stop movement, such as resisting gravity to maintain posture. Small, constant adjustments of the skeletal muscles are needed to hold a body upright or balanced in any position. Muscles also prevent excess movement of the bones and joints, maintaining skeletal stability and preventing skeletal structure damage or deformation.\n\nSkeletal muscles are located throughout the body at the openings of internal tracts to control the movement of various substances. These muscles allow functions, such as swallowing, urination, and defecation, to be under voluntary control. Skeletal muscles also protect internal organs (particularly abdominal and pelvic organs) by acting as an external barrier or shield to external trauma and by supporting the weight of the organs.\n<p id=\"fs-id1723952\">Skeletal muscles contribute to the maintenance of [pb_glossary id=\"349\"]homeostasis[\/pb_glossary] in the body by generating heat. This heat is very noticeable during exercise, when sustained muscle movement causes body temperature to rise, and in cases of extreme cold when shivering produces random skeletal muscle contractions to generate heat.<\/p>\n\n<div class=\"textbox textbox--key-takeaways\"><header class=\"textbox__header\">\n<h3 class=\"textbox__title\"><em>Did you know?<\/em><\/h3>\n<\/header>\n<div class=\"textbox__content\">\n\nThe gluteus maximus is the largest muscle and the heart is the hardest working muscle.\n\n<\/div>\n<\/div>\n<h4>Smooth Muscle<\/h4>\n<p id=\"fs-id2080434\">Smooth muscle, so named because the cells do not have striations, is present in the walls of hollow organs like the urinary bladder, uterus, stomach, intestines, and in the walls of passageways, such as the arteries and veins of the circulatory system, and the tracts of the respiratory, urinary, and reproductive systems. Smooth muscle is also present in the eyes, where it functions to change the size of the iris and alter the shape of the lens; and in the skin where it causes hair to stand erect in response to cold temperature or fear.<\/p>\n\n<h4>Cardiac Muscle<\/h4>\n<p id=\"fs-id1978114\">Cardiac muscle tissue is only found in the heart. Highly coordinated contractions of cardiac muscle pump blood into the vessels of the circulatory system. Similar to skeletal muscle, cardiac muscle is striated and organized into <strong>sarcomeres<\/strong>, possessing the same banding organization as skeletal muscle (see <a class=\"autogenerated-content\" href=\"#Figure7.1\">Figure 7.1<\/a>). Cardiac muscle fibers cells also are extensively branched and are connected to one another at their ends by intercalated discs. An <strong>intercalated disc<\/strong> allows the cardiac muscle cells to contract in a wave-like pattern so that the heart can work as a pump.<\/p>\n&nbsp;\n<div class=\"textbox textbox--exercises\"><header class=\"textbox__header\">\n<h3 class=\"textbox__title\">Concept Check<\/h3>\n<\/header>\n<div class=\"textbox__content\">\n<ul>\n \t<li>Compare and contrast the three types of muscle tissues.<\/li>\n \t<li>Where in the body do you find each of the muscle types?<\/li>\n<\/ul>\n<\/div>\n<\/div>\n<h2>Physiology (Function) of the Muscular System<\/h2>\nThe main function of the muscular system is to assist with <strong>movement<\/strong>. <span style=\"background-color: #ffffff;\">Muscles work as [pb_glossary id=\"553\"]antagonistic[\/pb_glossary] pairs. As one muscle contracts, the other muscle relaxes. This contraction pulls on <\/span><span style=\"background-color: #ffffff;\">the bones and assists with movement. Contraction is the shortening of the muscle fibers while relaxation lengthens the fibers. This sequence of relaxation and contraction is influenced by the nervous system. <\/span>\n\nMuscles also work to keep the <strong>posture<\/strong> of the body. This is done through muscle contraction where the trunk is kept straight either when sitting or standing.\n\n&nbsp;\n<div class=\"textbox textbox--key-takeaways\"><header class=\"textbox__header\">\n<h3 class=\"textbox__title\"><em>Did you know?<\/em><\/h3>\n<\/header>\n<div class=\"textbox__content\">\n\nIf all the muscles in the jaw worked together, it could close the teeth with a force as great as 200 pounds on the molars (Science Reference Section, 2019).\n\n<\/div>\n<\/div><\/figure>\n<h3>Naming of Muscles<\/h3>\nThere are many [pb_glossary id=\"552\"]nomenclatures[\/pb_glossary] for naming muscles. Some of these include:\n<ul>\n \t<li><strong>divisions<\/strong> - biceps, triceps, quadriceps<\/li>\n \t<li><strong>size<\/strong> - maximus (largest), minimus (smallest)<\/li>\n \t<li><strong>shape<\/strong> - deltoid (triangular), trapezius (trapezoid)<\/li>\n \t<li><strong>action<\/strong> - flexor (to flex), adductor (towards midline of the body)<\/li>\n<\/ul>\n<figure id=\"fig-ch11_02_01\">[caption id=\"\" align=\"aligncenter\" width=\"380\"]<img src=\"https:\/\/pressbooks.ccconline.org\/accphysicalgeology\/wp-content\/uploads\/sites\/228\/2019\/09\/1105_Anterior_and_Posterior_Views_of_Muscles-scaled-1.jpg\" alt=\"Muscular system. Image description available.\" width=\"380\" height=\"3033\"> <a id=\"Figure7.2\" href=\"\"><\/a>Figure 7.2. Overview of the Muscular System. On the anterior and posterior views of the muscular system above, superficial muscles (those at the surface) are shown on the right side of the body while deep muscles (those underneath the superficial muscles) are shown on the left half of the body. For the legs, superficial muscles are shown in the anterior view while the posterior view shows both superficial and deep muscles. From Betts et al., 2013. Licensed under <a href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0<\/a>. <a href=\"#Figure7.2id\">[Image description.]<\/a>[\/caption]\n<table class=\"grid landscape aligncenter\" style=\"border-collapse: collapse; width: 100%;\" border=\"0\"><caption><span style=\"color: #000000;\">Table 7.1. Understanding a Muscle Name from the Latin. Adapted from Betts et al., 2013. Licensed under <a style=\"color: #000000;\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0<\/a>.<\/span><\/caption>\n<thead>\n<tr>\n<td style=\"width: 16.6667%; height: 15px;\"><strong>EXAMPLE<\/strong><\/td>\n<td style=\"width: 11.3694%; height: 15px;\"><strong>WORD<\/strong><\/td>\n<td style=\"width: 20.1621%; height: 15px;\"><strong>LATIN ROOT 1<\/strong><\/td>\n<td style=\"width: 20.2485%; height: 15px;\"><strong>LATIN ROOT 2<\/strong><\/td>\n<td style=\"width: 14.8868%; height: 15px;\"><strong>MEANING<\/strong><\/td>\n<td style=\"width: 16.6667%; height: 15px;\"><strong>TRANSLATION<\/strong><\/td>\n<\/tr>\n<\/thead>\n<tbody>\n<tr style=\"height: 15px;\">\n<td style=\"width: 16.6667%; height: 45px;\" rowspan=\"3\"><strong>abductor digiti minimi<\/strong><\/td>\n<td style=\"width: 11.3694%; height: 15px;\">abductor<\/td>\n<td style=\"width: 20.1621%; height: 15px;\">ab = away from<\/td>\n<td style=\"width: 20.2485%; height: 15px;\">duct = to move<\/td>\n<td style=\"width: 14.8868%; height: 15px;\">a muscle that moves away from<\/td>\n<td style=\"width: 16.6667%; height: 45px;\" rowspan=\"3\">A muscle that moves the little finger or toe away<\/td>\n<\/tr>\n<tr style=\"height: 15px;\">\n<td style=\"width: 11.3694%; height: 15px;\">digiti<\/td>\n<td style=\"width: 20.1621%; height: 15px;\">digitus = digit<\/td>\n<td style=\"width: 20.2485%; height: 15px;\">n\/a<\/td>\n<td style=\"width: 14.8868%; height: 15px;\">refers to a finger or toe<\/td>\n<\/tr>\n<tr style=\"height: 15px;\">\n<td style=\"width: 11.3694%; height: 15px;\">minimi<\/td>\n<td style=\"width: 20.1621%; height: 15px;\">minimus = mini, tiny<\/td>\n<td style=\"width: 20.2485%; height: 15px;\">n\/a<\/td>\n<td style=\"width: 14.8868%; height: 15px;\">little<\/td>\n<\/tr>\n<tr style=\"height: 15px;\">\n<td style=\"width: 16.6667%; height: 45px;\" rowspan=\"3\"><strong>adductor digiti minimi<\/strong><\/td>\n<td style=\"width: 11.3694%; height: 15px;\">adductor<\/td>\n<td style=\"width: 20.1621%; height: 15px;\">ad = to, toward<\/td>\n<td style=\"width: 20.2485%; height: 15px;\">duct = to move<\/td>\n<td style=\"width: 14.8868%; height: 15px;\">a muscle that moves towards<\/td>\n<td style=\"width: 16.6667%; height: 15px;\" rowspan=\"3\">A muscle that moves the little finger or toe toward<\/td>\n<\/tr>\n<tr style=\"height: 15px;\">\n<td style=\"width: 11.3694%; height: 15px;\">digiti<\/td>\n<td style=\"width: 20.1621%; height: 15px;\">digitus = digit<\/td>\n<td style=\"width: 20.2485%; height: 15px;\">n\/a<\/td>\n<td style=\"width: 14.8868%; height: 15px;\">refers to a finger or toe<\/td>\n<\/tr>\n<tr style=\"height: 15px;\">\n<td style=\"width: 11.3694%; height: 15px;\">minimi<\/td>\n<td style=\"width: 20.1621%; height: 15px;\">minimus = mini, tiny<\/td>\n<td style=\"width: 20.2485%; height: 15px;\">n\/a<\/td>\n<td style=\"width: 14.8868%; height: 15px;\">little<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/figure>\n<figure id=\"fig-ch11_02_02\">\n<div>\n<h2>Common Abbreviations for the Muscular System<\/h2>\nMany terms and phrases related to the muscle system are abbreviated. Learn these common abbreviations by expanding the list below.\n\n&nbsp;\n\n<\/div><\/figure>\n<figure id=\"fig-ch10_01_01\">\n<div><article class=\"media media--type-image media--view-mode-full\">[h5p id=\"36\"]<\/article>\n<h2><span style=\"font-family: 'Cormorant Garamond', serif; text-align: initial;\">Diseases and Disorders of the Muscle System<\/span><\/h2>\n<h3>Duchenne Muscular Dystrophy<\/h3>\nDuchenne Muscular Dystrophy (DMD) is caused by the inability of the body to make dystrophin (a muscle protein). This causes the muscles to become weak as the person ages. This disease primarily affects boys. Signs and symptoms typically present before the age of six and may include a delay of motor milestones and progressive weakness in the lower extremities and pelvis. Since all muscles are affected, the person will eventually require a wheelchair and assistance with breathing (National Human Genome Research Institute, 2013). To learn more, please visit the <a href=\"https:\/\/rarediseases.info.nih.gov\/diseases\/6291\/duchenne-muscular-dystrophy\">Genetic and Rare Diseases Information Center's web page on Duchenne Muscular Dystrophy.<\/a>\n<h3>Cerebral Palsy<\/h3>\nCerebral palsy (CP) is caused by an interruption to the normal development of a person's brain leading to weakness with muscles. Depending on the area of the brain that is affected, signs and symptoms will vary in the type and severity between individuals. Balance and coordination are often challenging due to the inability to control muscles (Centers for Disease Control and Prevention, n.d.). To learn more, please visit the <a href=\"https:\/\/www.cdc.gov\/ncbddd\/cp\/facts.html\">Centers for Disease Control and Prevention's web page on cerebral palsy<\/a>.\n<h3>Carpal Tunnel Syndrome<\/h3>\nCarpal tunnel syndrome may present with pain, numbness, or weakness to the hand(s) caused by pressure on the median nerve. Some causes for this pressure are repetitive movements, trauma or injury to the wrist, or fluid retention related to pregnancy or menopause (National Institute of Neurological Disorders and Stroke, 2020). To learn more, visit the <a href=\"https:\/\/www.ninds.nih.gov\/Disorders\/Patient-Caregiver-Education\/Fact-Sheets\/Carpal-Tunnel-Syndrome-Fact-Sheet\">National Institute of Neurological Disorders and Stroke web page on carpal tunnel<\/a>.\n<h3>Paralysis<\/h3>\n<section><section>Paralysis is the loss of strength and control of the muscles in parts of the body. Paralysis can be localized where it affects specific areas such as the face, feet, vocal cords, et cetera, or it can be generalized where it affects a larger area of the body. There are various types of generalized paralysis, including:<\/section><\/section>\n<ul>\n \t<li><strong>Paresis<\/strong> - a partial paralysis wherein there is a moderate degree of muscular weakness<\/li>\n \t<li><strong>Paraplegia<\/strong> - paralysis that affects the lower extremities and lower portions of the trunk<\/li>\n \t<li><strong>Quadriplegia<\/strong> - affects all four limbs<\/li>\n \t<li><strong>Hemiplegia<\/strong> - affects one side of the body. For example, the arm and leg on the same side of the body (National Library of Medicine, 2021)<\/li>\n<\/ul>\nTo learn more about paralysis, please visit the <a href=\"https:\/\/my.clevelandclinic.org\/health\/diseases\/15345-paralysis\">Cleveland Clinic's web page on paralysis.<\/a>\n<h3>Sprain and Strain<\/h3>\nA <strong>sprain<\/strong> is an injury to a joint whereby a ligament is stretched or torn. Joints can be sprained as a result of falling, twisting, or being hit. Sprains most often occur in the ankle, although other joints can be affected. Signs and symptoms of a sprain include pain, swelling, bruising, and an inability to use the joint (National Institute of Arthritis and Musculoskeletal and Skin Diseases, n.d.).\n\nA <strong>strain<\/strong> is an injury to a muscle or a tendon caused by stretching or tearing. Tendons or muscles can be strained as a result of an injury, lifting heavy objects incorrectly, or overstress, and they can develop suddenly or over time. Signs and symptoms of a strain include pain, muscle spasms, swelling, cramping, and difficulty moving the muscle (National Institute of Arthritis and Musculoskeletal and Skin Diseases, n.d.).\n\n<article class=\"align-right embedded-entity\" data-langcode=\"en\" data-entity-uuid=\"fa80ee2e-9227-4c97-af76-b0485f9335ef\" data-entity-type=\"media\" data-entity-embed-display=\"view_mode:media.full\" data-embed-button=\"media\"><article class=\"media media--type-image media--view-mode-full\">\n<h2>Medical Terminology in Context<\/h2>\n<div><span style=\"text-align: initial; font-size: 1em;\">[h5p id=\"37\"]<\/span><\/div>\n<\/article><\/article>\n<h2>Medical Specialties and Procedures Related to Muscular System<\/h2>\n<h3>Orthopedic Surgeon<\/h3>\nOrthopedic surgeons are medical doctors who have specialized training in the prevention, diagnosis, treatment, and surgery of disorders and diseases related to the musculoskeletal systems (Bureau of Labor Statistics, 2021). For more details, please visit the <a href=\"https:\/\/www.facs.org\/education\/resources\/residency-search\/specialties\/ortho\">American College of Surgeons\u2019 web page on orthopedic surgery<\/a>.\n<h3>Massage Therapist<\/h3>\nMassage therapists manipulate muscles and other soft tissues through touch to relieve pain, aid the injury-healing process, and reduce stress. Massage therapists generally have a postsecondary degree, although requirements vary by state (Bureau of Labor Statistics, 2021b). To learn more about massage therapy, visit the <a href=\"https:\/\/www.amtamassage.org\/resources\/starting-your-massage-career\/\">American Massage Therapy Association's web page<\/a>.\n<h3>Diagnostic Procedures<\/h3>\n<strong>Electromyography (EMG)<\/strong> is a procedure that assesses the electrical signals muscles send while at rest and when they are used. During the test, a needle electrode is placed into the muscle, and a machine records the muscle activity. EMG can be used to diagnose myasthenia gravis, muscular dystrophy, and other conditions affecting the muscles (MedlinePlus, 2021a). To learn more, please visit the <a href=\"https:\/\/medlineplus.gov\/lab-tests\/electromyography-emg-and-nerve-conduction-studies\/\">Medline Plus web page on electromyography<\/a>.\n\n<strong>Magnetic Resonance Imaging (MRI)<\/strong> is a test that uses radio waves and a magnetic field to view internal organs and structures. MRI tests are used to diagnose a variety of conditions, such as torn ligaments or tumors. They are also used to view the brain and spinal cord (Medline Plus, 2021b).\n\n<strong style=\"text-align: initial; font-size: 1em;\">Range of Motion Testing <\/strong><span style=\"text-align: initial; font-size: 1em;\">is a diagnostic procedure used to determine the amount of movement around a specific joint.<\/span>\n<h2>Practice Terms Related to the Muscular System<\/h2>\n[h5p id=\"38\"]\n<h2>Muscular System Vocabulary<\/h2>\n<strong>Antagonistic<\/strong>\n\nIn opposition to each other.\n\n<strong>Bradykinesia<\/strong>\n\nCondition of slow movement.\n\n<strong>Cardiac muscle <\/strong>\n\nInvoluntary and found only in the heart. Highly coordinated contractions pump blood into the vessels of the circulatory system.\n\n<strong>Dyskinesia<\/strong>\n\nAbnormal involuntary movements of the extremities, trunk, or jaw.\n\n<strong>Electromyogram<\/strong>\n\nRecord of the electricity of the muscle.\n\n<strong>Electromyography<\/strong> <strong>(EMG) <\/strong>\n\nRecording of muscle electrical activity in response to a nerve\u2019s stimulation of the muscle.\n\n<strong>Fibromyalgia <\/strong>\n\nA common nonarticular rheumatic syndrome characterized by muscle pain.\n\n<strong>Hemiplegia<\/strong>\n\nParalysis on one side of the body.\n\n<strong>Hemostasis<\/strong>\n\nThe process by which the body seals a ruptured blood vessel to prevent further blood loss.\n\n<strong>Hyperkinesia<\/strong>\n\nExcessive movement of muscles of the body as a whole.\n\n<strong>Hypertrophy<\/strong>\n\nThe enlargement of muscles.\n\n<strong>Magnetic Resonance Imaging<\/strong> <strong>(MRI) <\/strong>\n\nA procedure in which radio waves and a powerful magnet linked to a computer are used to create detailed pictures of areas inside the body.\n\n<strong>Muscular dystrophy<\/strong>\n\nA general term for the group of inherited myopathies that are characterized by wasting and weakness of the skeletal muscle.\n\n<strong>Myalgia<\/strong>\n\nPain in a muscle or group of muscles.\n\n<strong>Myasthenia Gravis <\/strong>\n\nA disease in which antibodies made by a person\u2019s immune system prevent certain nerve-muscle interactions, causing weakness in the arms and legs, vision problems, and drooping eyelids or head.\n\n<strong>Myeloma<\/strong>\n\nCancer that arises in plasma cells.\n\n<strong>Paraplegia<\/strong>\n\nParalysis that affects both legs and lower part of the body.\n\n<strong>Paresis<\/strong>\n\nPartial paralysis wherein there is still some control of the muscles.\n\n<strong>Polymyositis<\/strong>\n\nAn inflammatory disease of the muscles closest to the center of the body.\n\n<strong>Quadriplegia<\/strong>\n\nParalysis of all four limbs.\n\n<strong>Rhabdomyolysis<\/strong>\n\nNecrosis or disintegration of skeletal muscle.\n\n<strong>Skeletal muscle <\/strong>\n\nThe muscles responsible for voluntary muscle movement; also called striated muscle.\n\n<strong>Smooth muscle <\/strong>\n\nThe muscles responsible for involuntary muscle movement; also called visceral muscle.\n\n<strong>Sprain<\/strong>\n\nThe stretching or tearing of the supporting ligaments.\n\n<strong>Strain<\/strong>\n\nAn overstretching or overexertion of a muscle or tendon.\n\n<strong>Tendinitis<\/strong>\n\nInflammation of the tendon.\n<h2>Test Yourself<\/h2>\n[h5p id=\"39\"]\n<h2>References<\/h2>\nBureau of Labor Statistics. (2021a). Physicians and surgeons. In <em>Occupational outlook handbook<\/em>. U.S. Department of Labor. <a href=\"https:\/\/www.bls.gov\/ooh\/healthcare\/physicians-and-surgeons.htm\">https:\/\/www.bls.gov\/ooh\/healthcare\/physicians-and-surgeons.htm<\/a>\n\nBureau of Labor Statistics. (2021b). Massage therapists. In <em>Occupational outlook handbook<\/em>. U.S. Department of Labor. <a href=\"https:\/\/www.bls.gov\/ooh\/healthcare\/massage-therapists.htm\">https:\/\/www.bls.gov\/ooh\/healthcare\/massage-therapists.htm<\/a>\n\nCenters for Disease Control and Prevention. (n.d.). <em>What is cerebral palsy?<\/em> <a href=\"https:\/\/www.cdc.gov\/ncbddd\/cp\/facts.html\">https:\/\/www.cdc.gov\/ncbddd\/cp\/facts.html<\/a>\n\nCrashCourse. (2015, July 15). <em>Muscles, part 2 - organismal level: Crash course A&amp;P #22<\/em> [Video]. YouTube. <a href=\"https:\/\/youtu.be\/I80Xx7pA9hQ\">https:\/\/youtu.be\/I80Xx7pA9hQ<\/a>\n\nNational Library of Medicine. (2021). <em>Medical Subject Headings database.<\/em> National Institutes of Health, U.S. Department of Health and Human Services. <a href=\"https:\/\/www.nlm.nih.gov\/mesh\/meshhome.html\">https:\/\/www.nlm.nih.gov\/mesh\/meshhome.html<\/a>\n\nMedlinePlus. (2021a). <em>Electromyography (EMG) and nerve conduction studies. <\/em>U.S. National Library of Medicine. <a href=\"https:\/\/medlineplus.gov\/lab-tests\/electromyography-emg-and-nerve-conduction-studies\/\">https:\/\/medlineplus.gov\/lab-tests\/electromyography-emg-and-nerve-conduction-studies<\/a>\n\nMedlinePlus. (2021b). <em>MRI scans<\/em>. U.S. National Library of Medicine, U.S. Department of Health and Human Services. <a href=\"https:\/\/medlineplus.gov\/mriscans.html\">https:\/\/medlineplus.gov\/mriscans.html<\/a>\n\nNational Human Genome Research Institute (2013). <em>About Duchenne Muscular Dystrophy<\/em>. National Institutes of Health, U.S. Department of Health and Human Services. <a href=\"https:\/\/www.genome.gov\/Genetic-Disorders\/Duchenne-Muscular-Dystrophy\">https:\/\/www.genome.gov\/Genetic-Disorders\/Duchenne-Muscular-Dystrophy<\/a>\n\nNational Institute of Arthritis and Musculoskeletal and Skin Diseases. (n.d.). <em>Sprain vs. strain<\/em>. National Institutes of Health, U.S. Department of Health and Human Services. <a href=\"https:\/\/www.niams.nih.gov\/health-topics\/sprains-and-strains#tab-symptoms\">https:\/\/www.niams.nih.gov\/health-topics\/sprains-and-strains#tab-symptoms<\/a>\n\nNational Institute of Neurological Disorders and Stroke. (2020). <em>Carpal tunnel syndrome fact sheet<\/em>. National Institutes of Health, U.S. Department of Health and Human Services. <a href=\"https:\/\/www.ninds.nih.gov\/Disorders\/Patient-Caregiver-Education\/Fact-Sheets\/Carpal-Tunnel-Syndrome-Fact-Sheet\">https:\/\/www.ninds.nih.gov\/Disorders\/Patient-Caregiver-Education\/Fact-Sheets\/Carpal-Tunnel-Syndrome-Fact-Sheet<\/a>\n\nScience Reference Section. (2019). <em>What is the strongest muscle in the human body?<\/em> Library of Congress. <a href=\"https:\/\/www.loc.gov\/everyday-mysteries\/biology-and-human-anatomy\/item\/what-is-the-strongest-muscle-in-the-human-body\/\">https:\/\/www.loc.gov\/everyday-mysteries\/biology-and-human-anatomy\/item\/what-is-the-strongest-muscle-in-the-human-body\/<\/a>\n\n<\/div><\/figure>\n<figure id=\"fig-ch10_01_01\"><section id=\"fs-id1707953\">\n<figure id=\"fig-ch10_01_01\"><section id=\"fs-id1398723\">\n<h2>Image Descriptions<\/h2>\n<a id=\"Figure7.1id\" href=\"\"><\/a> <strong>Figure 7.1 image description:<\/strong> The top panel shows a micrographic view of skeletal muscle. The middle panel shows a micrographic view of smooth muscle. The bottom panel shows a micrographic view of cardiac muscle. <a href=\"#Figure7.1\">[Return to Figure 7.1].<\/a>\n\n<a id=\"Figure7.2id\" href=\"\"><\/a> <strong>Figure 7.2 image description:<\/strong> The top panel shows the anterior view of the human body with the major muscles labeled. Labels read (from the top, head): occipitofrontalis (frontal belly), sternocleidomastoid, trapezius, deltoid, pectoralis minor, serratus anterior, pectoralis major, arm muscles: biceps brachii, brachialis, brachioradialis, pronator teres, flexor carpi radialis, abdominal: rectus abdominis, abdominal external oblique, lower body: tensor fasciae latae, iliopsoas, pectineus, adductor longus, sartorius, gracilis, rectus femoris, vastus lateralis, vastus medialis, fibularis longus, tibialis anterior. The bottom panel shows the posterior view of the human body with the major muscles labeled. Labels read (from the top, head, left side): epicranial aponeurosis, occipitofrontalis, splenius capitis, levator scapulae, rhombus, trapezius, supraspinatus, teres minor, infraspinatus, teres major, triceps brachii, serratus posterior inferior, external oblique, lower body: gluteus medius, gluteus maximus, semimembranosus, peroneus longus, tibialis posterior, (right side, from top) trapezius, deltoid, latissimus dorsi, arm: brachioradialis, extensor carpi radialis, extensor digitorum, extensor carpi ulnaris, flexor carpi ulnaris, lower body: gluteus minimus, gemellus muscles, biceps femoris, semitendinosus, gracilis, gastrocnemius, soleus. <a href=\"#Figure7.2\">[Return to Figure 7.2].<\/a>\n<div class=\"textbox shaded\">Unless otherwise indicated, this chapter contains material adapted from <a href=\"https:\/\/openstax.org\/books\/anatomy-and-physiology\/pages\/1-introduction\"><em>Anatomy and Physiology<\/em><\/a> (on <a href=\"https:\/\/openstax.org\/\">OpenStax<\/a>), by Betts et al. and is used under a <a href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 international license<\/a>. Download and access this book for free at <a href=\"https:\/\/openstax.org\/books\/anatomy-and-physiology\/pages\/1-introduction\">https:\/\/openstax.org\/books\/anatomy-and-physiology\/pages\/1-introduction<\/a>.<\/div>\n&nbsp;\n\n<\/section><\/figure>\n<\/section><\/figure>","rendered":"<div class=\"textbox textbox--learning-objectives\">\n<header class=\"textbox__header\">\n<h2 class=\"textbox__title\"><em>Learning Objectives<\/em><\/h2>\n<\/header>\n<div class=\"textbox__content\">\n<ul>\n<li>Examine the anatomy of the muscular system<\/li>\n<li>Determine the main functions of the muscular system<\/li>\n<li>Differentiate the medical terms of the muscular system and common abbreviations<\/li>\n<li>Discover common diseases, disorders, and procedures related to the muscular system<\/li>\n<li>Recognize the medical specialties associated with the muscular system<\/li>\n<\/ul>\n<\/div>\n<\/div>\n<h2>Muscular System Word Parts<\/h2>\n<p>Click on prefixes, combining forms, and suffixes to reveal a list of word parts to memorize for the Muscular System.<\/p>\n<p>&nbsp;<\/p>\n<div id=\"h5p-34\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-34\" class=\"h5p-iframe\" data-content-id=\"34\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Muscular System: Word Parts\"><\/iframe><\/div>\n<\/div>\n<h2>Introduction to the Muscular System<\/h2>\n<p>When most people think of muscles, they think of the muscles that are visible just under the skin, particularly of the limbs. These are skeletal muscles, so-named because most of them move the skeleton, but there are two additional types of muscles: the smooth muscle and the cardiac muscle. The body has over 600 muscles which contribute significantly to the body&#8217;s weight.<\/p>\n<h3>Watch this video:<\/h3>\n<div class=\"textbox shaded\">\n<p><iframe loading=\"lazy\" id=\"oembed-1\" title=\"Muscles, Part 2 - Organismal Level: Crash Course Anatomy &amp; Physiology #22\" width=\"500\" height=\"281\" src=\"https:\/\/www.youtube.com\/embed\/I80Xx7pA9hQ?feature=oembed&#38;rel=0&#38;rel=0\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\"><\/iframe><\/p>\n<p><em>Media 7.1 <a href=\"https:\/\/youtu.be\/I80Xx7pA9hQ\">Muscles, Part 2 &#8211; Organismal Level: Crash Course A&amp;P #22<\/a> [Online video]. Copyright 2015 by <a href=\"https:\/\/www.youtube.com\/channel\/UCX6b17PVsYBQ0ip5gyeme-Q\">CrashCourse<\/a>.<\/em><\/p>\n<\/div>\n<h2>Medical Terms Related to the Muscular System<\/h2>\n<div id=\"h5p-35\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-35\" class=\"h5p-iframe\" data-content-id=\"35\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Muscular System: Medical Terms\"><\/iframe><\/div>\n<\/div>\n<h2 id=\"fs-id1840923\" style=\"margin-top: 2.14286em; margin-bottom: 1.42857em;\">Anatomy (Structures) of the Muscular System<\/h2>\n<p>Muscle is one of the four primary tissue types of the body, and it is made up of specialized cells called fibers. The body contains three types of muscle tissue: <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_73_575\">skeletal muscle<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_73_576\">cardiac muscle<\/a>, and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_73_577\">smooth muscle<\/a> (see <a href=\"#Figure7.1\">Figure 7.1<\/a>). All three muscle tissues have some properties in common; they all exhibit a quality called <strong>excitability<\/strong> as their plasma membranes can change their electrical states (from polarized to depolarized) and send an electrical wave called an action potential along the entire length of the membrane. <strong>Fascia<\/strong> is fibrous connective tissue that encloses muscles.<\/p>\n<figure id=\"fig-ch10_01_01\">\n<figure style=\"width: 320px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/opentextbc.ca\/anatomyandphysiology\/wp-content\/uploads\/sites\/142\/2016\/03\/414_Skeletal_Smooth_Cardiac-1.jpg\" alt=\"This figure show the micrographs of skeletal muscle, smooth muscle, and cardiac muscle cells.\" width=\"320\" height=\"1068\" \/><figcaption class=\"wp-caption-text\"><a id=\"Figure7.1\" href=\"\"><\/a>Figure 7.1 The Three Types of Muscle Tissue. The body contains three types of muscle tissue: (a) skeletal muscle, (b) smooth muscle, and (c) cardiac muscle. (Micrographs provided by the Regents of University of Michigan Medical School \u00a9 2012). From Betts et al., 2013. Licensed under <a href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0<\/a>. <a href=\"#Figure7.1id\">[Image description.]<\/a><\/figcaption><\/figure>\n<h3>Three Types of Muscle Tissues<\/h3>\n<ul>\n<li><strong>Skeletal<\/strong> &#8211; closely associated with the skeletal system. Also known as striated muscles, they are responsible for voluntary muscle movement, such as swallowing, et cetera.<\/li>\n<li><strong>Smooth<\/strong> &#8211; mainly associated with the walls of the internal organs. Also known as visceral muscles, they are responsible for involuntary muscle movement, such as breathing, et cetera.<\/li>\n<li><strong>Cardiac<\/strong> &#8211; heart muscle or myocardium. Its appearance is similar to a skeletal muscle and is responsible for the pumping of blood. It gives the heart beat.<\/li>\n<\/ul>\n<div class=\"textbox textbox--sidebar textbox--key-takeaways\"><\/div>\n<h4>Skeletal Muscle<\/h4>\n<p>Skeletal muscles act not only to produce movement but also to stop movement, such as resisting gravity to maintain posture. Small, constant adjustments of the skeletal muscles are needed to hold a body upright or balanced in any position. Muscles also prevent excess movement of the bones and joints, maintaining skeletal stability and preventing skeletal structure damage or deformation.<\/p>\n<p>Skeletal muscles are located throughout the body at the openings of internal tracts to control the movement of various substances. These muscles allow functions, such as swallowing, urination, and defecation, to be under voluntary control. Skeletal muscles also protect internal organs (particularly abdominal and pelvic organs) by acting as an external barrier or shield to external trauma and by supporting the weight of the organs.<\/p>\n<p id=\"fs-id1723952\">Skeletal muscles contribute to the maintenance of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_73_349\">homeostasis<\/a> in the body by generating heat. This heat is very noticeable during exercise, when sustained muscle movement causes body temperature to rise, and in cases of extreme cold when shivering produces random skeletal muscle contractions to generate heat.<\/p>\n<div class=\"textbox textbox--key-takeaways\">\n<header class=\"textbox__header\">\n<h3 class=\"textbox__title\"><em>Did you know?<\/em><\/h3>\n<\/header>\n<div class=\"textbox__content\">\n<p>The gluteus maximus is the largest muscle and the heart is the hardest working muscle.<\/p>\n<\/div>\n<\/div>\n<h4>Smooth Muscle<\/h4>\n<p id=\"fs-id2080434\">Smooth muscle, so named because the cells do not have striations, is present in the walls of hollow organs like the urinary bladder, uterus, stomach, intestines, and in the walls of passageways, such as the arteries and veins of the circulatory system, and the tracts of the respiratory, urinary, and reproductive systems. Smooth muscle is also present in the eyes, where it functions to change the size of the iris and alter the shape of the lens; and in the skin where it causes hair to stand erect in response to cold temperature or fear.<\/p>\n<h4>Cardiac Muscle<\/h4>\n<p id=\"fs-id1978114\">Cardiac muscle tissue is only found in the heart. Highly coordinated contractions of cardiac muscle pump blood into the vessels of the circulatory system. Similar to skeletal muscle, cardiac muscle is striated and organized into <strong>sarcomeres<\/strong>, possessing the same banding organization as skeletal muscle (see <a class=\"autogenerated-content\" href=\"#Figure7.1\">Figure 7.1<\/a>). Cardiac muscle fibers cells also are extensively branched and are connected to one another at their ends by intercalated discs. An <strong>intercalated disc<\/strong> allows the cardiac muscle cells to contract in a wave-like pattern so that the heart can work as a pump.<\/p>\n<p>&nbsp;<\/p>\n<div class=\"textbox textbox--exercises\">\n<header class=\"textbox__header\">\n<h3 class=\"textbox__title\">Concept Check<\/h3>\n<\/header>\n<div class=\"textbox__content\">\n<ul>\n<li>Compare and contrast the three types of muscle tissues.<\/li>\n<li>Where in the body do you find each of the muscle types?<\/li>\n<\/ul>\n<\/div>\n<\/div>\n<h2>Physiology (Function) of the Muscular System<\/h2>\n<p>The main function of the muscular system is to assist with <strong>movement<\/strong>. <span style=\"background-color: #ffffff;\">Muscles work as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_73_553\">antagonistic<\/a> pairs. As one muscle contracts, the other muscle relaxes. This contraction pulls on <\/span><span style=\"background-color: #ffffff;\">the bones and assists with movement. Contraction is the shortening of the muscle fibers while relaxation lengthens the fibers. This sequence of relaxation and contraction is influenced by the nervous system. <\/span><\/p>\n<p>Muscles also work to keep the <strong>posture<\/strong> of the body. This is done through muscle contraction where the trunk is kept straight either when sitting or standing.<\/p>\n<p>&nbsp;<\/p>\n<div class=\"textbox textbox--key-takeaways\">\n<header class=\"textbox__header\">\n<h3 class=\"textbox__title\"><em>Did you know?<\/em><\/h3>\n<\/header>\n<div class=\"textbox__content\">\n<p>If all the muscles in the jaw worked together, it could close the teeth with a force as great as 200 pounds on the molars (Science Reference Section, 2019).<\/p>\n<\/div>\n<\/div>\n<\/figure>\n<h3>Naming of Muscles<\/h3>\n<p>There are many <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_73_552\">nomenclatures<\/a> for naming muscles. Some of these include:<\/p>\n<ul>\n<li><strong>divisions<\/strong> &#8211; biceps, triceps, quadriceps<\/li>\n<li><strong>size<\/strong> &#8211; maximus (largest), minimus (smallest)<\/li>\n<li><strong>shape<\/strong> &#8211; deltoid (triangular), trapezius (trapezoid)<\/li>\n<li><strong>action<\/strong> &#8211; flexor (to flex), adductor (towards midline of the body)<\/li>\n<\/ul>\n<figure id=\"fig-ch11_02_01\">\n<figure style=\"width: 380px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/pressbooks.ccconline.org\/accphysicalgeology\/wp-content\/uploads\/sites\/228\/2019\/09\/1105_Anterior_and_Posterior_Views_of_Muscles-scaled-1.jpg\" alt=\"Muscular system. Image description available.\" width=\"380\" height=\"3033\" \/><figcaption class=\"wp-caption-text\"><a id=\"Figure7.2\" href=\"\"><\/a>Figure 7.2. Overview of the Muscular System. On the anterior and posterior views of the muscular system above, superficial muscles (those at the surface) are shown on the right side of the body while deep muscles (those underneath the superficial muscles) are shown on the left half of the body. For the legs, superficial muscles are shown in the anterior view while the posterior view shows both superficial and deep muscles. From Betts et al., 2013. Licensed under <a href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0<\/a>. <a href=\"#Figure7.2id\">[Image description.]<\/a><\/figcaption><\/figure>\n<table class=\"grid landscape aligncenter\" style=\"border-collapse: collapse; width: 100%;\">\n<caption><span style=\"color: #000000;\">Table 7.1. Understanding a Muscle Name from the Latin. Adapted from Betts et al., 2013. Licensed under <a style=\"color: #000000;\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0<\/a>.<\/span><\/caption>\n<thead>\n<tr>\n<td style=\"width: 16.6667%; height: 15px;\"><strong>EXAMPLE<\/strong><\/td>\n<td style=\"width: 11.3694%; height: 15px;\"><strong>WORD<\/strong><\/td>\n<td style=\"width: 20.1621%; height: 15px;\"><strong>LATIN ROOT 1<\/strong><\/td>\n<td style=\"width: 20.2485%; height: 15px;\"><strong>LATIN ROOT 2<\/strong><\/td>\n<td style=\"width: 14.8868%; height: 15px;\"><strong>MEANING<\/strong><\/td>\n<td style=\"width: 16.6667%; height: 15px;\"><strong>TRANSLATION<\/strong><\/td>\n<\/tr>\n<\/thead>\n<tbody>\n<tr style=\"height: 15px;\">\n<td style=\"width: 16.6667%; height: 45px;\" rowspan=\"3\"><strong>abductor digiti minimi<\/strong><\/td>\n<td style=\"width: 11.3694%; height: 15px;\">abductor<\/td>\n<td style=\"width: 20.1621%; height: 15px;\">ab = away from<\/td>\n<td style=\"width: 20.2485%; height: 15px;\">duct = to move<\/td>\n<td style=\"width: 14.8868%; height: 15px;\">a muscle that moves away from<\/td>\n<td style=\"width: 16.6667%; height: 45px;\" rowspan=\"3\">A muscle that moves the little finger or toe away<\/td>\n<\/tr>\n<tr style=\"height: 15px;\">\n<td style=\"width: 11.3694%; height: 15px;\">digiti<\/td>\n<td style=\"width: 20.1621%; height: 15px;\">digitus = digit<\/td>\n<td style=\"width: 20.2485%; height: 15px;\">n\/a<\/td>\n<td style=\"width: 14.8868%; height: 15px;\">refers to a finger or toe<\/td>\n<\/tr>\n<tr style=\"height: 15px;\">\n<td style=\"width: 11.3694%; height: 15px;\">minimi<\/td>\n<td style=\"width: 20.1621%; height: 15px;\">minimus = mini, tiny<\/td>\n<td style=\"width: 20.2485%; height: 15px;\">n\/a<\/td>\n<td style=\"width: 14.8868%; height: 15px;\">little<\/td>\n<\/tr>\n<tr style=\"height: 15px;\">\n<td style=\"width: 16.6667%; height: 45px;\" rowspan=\"3\"><strong>adductor digiti minimi<\/strong><\/td>\n<td style=\"width: 11.3694%; height: 15px;\">adductor<\/td>\n<td style=\"width: 20.1621%; height: 15px;\">ad = to, toward<\/td>\n<td style=\"width: 20.2485%; height: 15px;\">duct = to move<\/td>\n<td style=\"width: 14.8868%; height: 15px;\">a muscle that moves towards<\/td>\n<td style=\"width: 16.6667%; height: 15px;\" rowspan=\"3\">A muscle that moves the little finger or toe toward<\/td>\n<\/tr>\n<tr style=\"height: 15px;\">\n<td style=\"width: 11.3694%; height: 15px;\">digiti<\/td>\n<td style=\"width: 20.1621%; height: 15px;\">digitus = digit<\/td>\n<td style=\"width: 20.2485%; height: 15px;\">n\/a<\/td>\n<td style=\"width: 14.8868%; height: 15px;\">refers to a finger or toe<\/td>\n<\/tr>\n<tr style=\"height: 15px;\">\n<td style=\"width: 11.3694%; height: 15px;\">minimi<\/td>\n<td style=\"width: 20.1621%; height: 15px;\">minimus = mini, tiny<\/td>\n<td style=\"width: 20.2485%; height: 15px;\">n\/a<\/td>\n<td style=\"width: 14.8868%; height: 15px;\">little<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/figure>\n<figure id=\"fig-ch11_02_02\">\n<div>\n<h2>Common Abbreviations for the Muscular System<\/h2>\n<p>Many terms and phrases related to the muscle system are abbreviated. Learn these common abbreviations by expanding the list below.<\/p>\n<p>&nbsp;<\/p>\n<\/div>\n<\/figure>\n<figure>\n<div>\n<article class=\"media media--type-image media--view-mode-full\">\n<div id=\"h5p-36\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-36\" class=\"h5p-iframe\" data-content-id=\"36\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Muscular System: Abbreviations\"><\/iframe><\/div>\n<\/div>\n<\/article>\n<h2><span style=\"font-family: 'Cormorant Garamond', serif; text-align: initial;\">Diseases and Disorders of the Muscle System<\/span><\/h2>\n<h3>Duchenne Muscular Dystrophy<\/h3>\n<p>Duchenne Muscular Dystrophy (DMD) is caused by the inability of the body to make dystrophin (a muscle protein). This causes the muscles to become weak as the person ages. This disease primarily affects boys. Signs and symptoms typically present before the age of six and may include a delay of motor milestones and progressive weakness in the lower extremities and pelvis. Since all muscles are affected, the person will eventually require a wheelchair and assistance with breathing (National Human Genome Research Institute, 2013). To learn more, please visit the <a href=\"https:\/\/rarediseases.info.nih.gov\/diseases\/6291\/duchenne-muscular-dystrophy\">Genetic and Rare Diseases Information Center&#8217;s web page on Duchenne Muscular Dystrophy.<\/a><\/p>\n<h3>Cerebral Palsy<\/h3>\n<p>Cerebral palsy (CP) is caused by an interruption to the normal development of a person&#8217;s brain leading to weakness with muscles. Depending on the area of the brain that is affected, signs and symptoms will vary in the type and severity between individuals. Balance and coordination are often challenging due to the inability to control muscles (Centers for Disease Control and Prevention, n.d.). To learn more, please visit the <a href=\"https:\/\/www.cdc.gov\/ncbddd\/cp\/facts.html\">Centers for Disease Control and Prevention&#8217;s web page on cerebral palsy<\/a>.<\/p>\n<h3>Carpal Tunnel Syndrome<\/h3>\n<p>Carpal tunnel syndrome may present with pain, numbness, or weakness to the hand(s) caused by pressure on the median nerve. Some causes for this pressure are repetitive movements, trauma or injury to the wrist, or fluid retention related to pregnancy or menopause (National Institute of Neurological Disorders and Stroke, 2020). To learn more, visit the <a href=\"https:\/\/www.ninds.nih.gov\/Disorders\/Patient-Caregiver-Education\/Fact-Sheets\/Carpal-Tunnel-Syndrome-Fact-Sheet\">National Institute of Neurological Disorders and Stroke web page on carpal tunnel<\/a>.<\/p>\n<h3>Paralysis<\/h3>\n<section>\n<section>Paralysis is the loss of strength and control of the muscles in parts of the body. Paralysis can be localized where it affects specific areas such as the face, feet, vocal cords, et cetera, or it can be generalized where it affects a larger area of the body. There are various types of generalized paralysis, including:<\/section>\n<\/section>\n<ul>\n<li><strong>Paresis<\/strong> &#8211; a partial paralysis wherein there is a moderate degree of muscular weakness<\/li>\n<li><strong>Paraplegia<\/strong> &#8211; paralysis that affects the lower extremities and lower portions of the trunk<\/li>\n<li><strong>Quadriplegia<\/strong> &#8211; affects all four limbs<\/li>\n<li><strong>Hemiplegia<\/strong> &#8211; affects one side of the body. For example, the arm and leg on the same side of the body (National Library of Medicine, 2021)<\/li>\n<\/ul>\n<p>To learn more about paralysis, please visit the <a href=\"https:\/\/my.clevelandclinic.org\/health\/diseases\/15345-paralysis\">Cleveland Clinic&#8217;s web page on paralysis.<\/a><\/p>\n<h3>Sprain and Strain<\/h3>\n<p>A <strong>sprain<\/strong> is an injury to a joint whereby a ligament is stretched or torn. Joints can be sprained as a result of falling, twisting, or being hit. Sprains most often occur in the ankle, although other joints can be affected. Signs and symptoms of a sprain include pain, swelling, bruising, and an inability to use the joint (National Institute of Arthritis and Musculoskeletal and Skin Diseases, n.d.).<\/p>\n<p>A <strong>strain<\/strong> is an injury to a muscle or a tendon caused by stretching or tearing. Tendons or muscles can be strained as a result of an injury, lifting heavy objects incorrectly, or overstress, and they can develop suddenly or over time. Signs and symptoms of a strain include pain, muscle spasms, swelling, cramping, and difficulty moving the muscle (National Institute of Arthritis and Musculoskeletal and Skin Diseases, n.d.).<\/p>\n<article class=\"align-right embedded-entity\" data-langcode=\"en\" data-entity-uuid=\"fa80ee2e-9227-4c97-af76-b0485f9335ef\" data-entity-type=\"media\" data-entity-embed-display=\"view_mode:media.full\" data-embed-button=\"media\">\n<article class=\"media media--type-image media--view-mode-full\">\n<h2>Medical Terminology in Context<\/h2>\n<div><span style=\"text-align: initial; font-size: 1em;\"><\/p>\n<div id=\"h5p-37\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-37\" class=\"h5p-iframe\" data-content-id=\"37\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Musculoskeletal System: Referral Letter\"><\/iframe><\/div>\n<\/div>\n<p><\/span><\/div>\n<\/article>\n<\/article>\n<h2>Medical Specialties and Procedures Related to Muscular System<\/h2>\n<h3>Orthopedic Surgeon<\/h3>\n<p>Orthopedic surgeons are medical doctors who have specialized training in the prevention, diagnosis, treatment, and surgery of disorders and diseases related to the musculoskeletal systems (Bureau of Labor Statistics, 2021). For more details, please visit the <a href=\"https:\/\/www.facs.org\/education\/resources\/residency-search\/specialties\/ortho\">American College of Surgeons\u2019 web page on orthopedic surgery<\/a>.<\/p>\n<h3>Massage Therapist<\/h3>\n<p>Massage therapists manipulate muscles and other soft tissues through touch to relieve pain, aid the injury-healing process, and reduce stress. Massage therapists generally have a postsecondary degree, although requirements vary by state (Bureau of Labor Statistics, 2021b). To learn more about massage therapy, visit the <a href=\"https:\/\/www.amtamassage.org\/resources\/starting-your-massage-career\/\">American Massage Therapy Association&#8217;s web page<\/a>.<\/p>\n<h3>Diagnostic Procedures<\/h3>\n<p><strong>Electromyography (EMG)<\/strong> is a procedure that assesses the electrical signals muscles send while at rest and when they are used. During the test, a needle electrode is placed into the muscle, and a machine records the muscle activity. EMG can be used to diagnose myasthenia gravis, muscular dystrophy, and other conditions affecting the muscles (MedlinePlus, 2021a). To learn more, please visit the <a href=\"https:\/\/medlineplus.gov\/lab-tests\/electromyography-emg-and-nerve-conduction-studies\/\">Medline Plus web page on electromyography<\/a>.<\/p>\n<p><strong>Magnetic Resonance Imaging (MRI)<\/strong> is a test that uses radio waves and a magnetic field to view internal organs and structures. MRI tests are used to diagnose a variety of conditions, such as torn ligaments or tumors. They are also used to view the brain and spinal cord (Medline Plus, 2021b).<\/p>\n<p><strong style=\"text-align: initial; font-size: 1em;\">Range of Motion Testing <\/strong><span style=\"text-align: initial; font-size: 1em;\">is a diagnostic procedure used to determine the amount of movement around a specific joint.<\/span><\/p>\n<h2>Practice Terms Related to the Muscular System<\/h2>\n<div id=\"h5p-38\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-38\" class=\"h5p-iframe\" data-content-id=\"38\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Muscular System: Terms not easily broken into word parts\"><\/iframe><\/div>\n<\/div>\n<h2>Muscular System Vocabulary<\/h2>\n<p><strong>Antagonistic<\/strong><\/p>\n<p>In opposition to each other.<\/p>\n<p><strong>Bradykinesia<\/strong><\/p>\n<p>Condition of slow movement.<\/p>\n<p><strong>Cardiac muscle <\/strong><\/p>\n<p>Involuntary and found only in the heart. Highly coordinated contractions pump blood into the vessels of the circulatory system.<\/p>\n<p><strong>Dyskinesia<\/strong><\/p>\n<p>Abnormal involuntary movements of the extremities, trunk, or jaw.<\/p>\n<p><strong>Electromyogram<\/strong><\/p>\n<p>Record of the electricity of the muscle.<\/p>\n<p><strong>Electromyography<\/strong> <strong>(EMG) <\/strong><\/p>\n<p>Recording of muscle electrical activity in response to a nerve\u2019s stimulation of the muscle.<\/p>\n<p><strong>Fibromyalgia <\/strong><\/p>\n<p>A common nonarticular rheumatic syndrome characterized by muscle pain.<\/p>\n<p><strong>Hemiplegia<\/strong><\/p>\n<p>Paralysis on one side of the body.<\/p>\n<p><strong>Hemostasis<\/strong><\/p>\n<p>The process by which the body seals a ruptured blood vessel to prevent further blood loss.<\/p>\n<p><strong>Hyperkinesia<\/strong><\/p>\n<p>Excessive movement of muscles of the body as a whole.<\/p>\n<p><strong>Hypertrophy<\/strong><\/p>\n<p>The enlargement of muscles.<\/p>\n<p><strong>Magnetic Resonance Imaging<\/strong> <strong>(MRI) <\/strong><\/p>\n<p>A procedure in which radio waves and a powerful magnet linked to a computer are used to create detailed pictures of areas inside the body.<\/p>\n<p><strong>Muscular dystrophy<\/strong><\/p>\n<p>A general term for the group of inherited myopathies that are characterized by wasting and weakness of the skeletal muscle.<\/p>\n<p><strong>Myalgia<\/strong><\/p>\n<p>Pain in a muscle or group of muscles.<\/p>\n<p><strong>Myasthenia Gravis <\/strong><\/p>\n<p>A disease in which antibodies made by a person\u2019s immune system prevent certain nerve-muscle interactions, causing weakness in the arms and legs, vision problems, and drooping eyelids or head.<\/p>\n<p><strong>Myeloma<\/strong><\/p>\n<p>Cancer that arises in plasma cells.<\/p>\n<p><strong>Paraplegia<\/strong><\/p>\n<p>Paralysis that affects both legs and lower part of the body.<\/p>\n<p><strong>Paresis<\/strong><\/p>\n<p>Partial paralysis wherein there is still some control of the muscles.<\/p>\n<p><strong>Polymyositis<\/strong><\/p>\n<p>An inflammatory disease of the muscles closest to the center of the body.<\/p>\n<p><strong>Quadriplegia<\/strong><\/p>\n<p>Paralysis of all four limbs.<\/p>\n<p><strong>Rhabdomyolysis<\/strong><\/p>\n<p>Necrosis or disintegration of skeletal muscle.<\/p>\n<p><strong>Skeletal muscle <\/strong><\/p>\n<p>The muscles responsible for voluntary muscle movement; also called striated muscle.<\/p>\n<p><strong>Smooth muscle <\/strong><\/p>\n<p>The muscles responsible for involuntary muscle movement; also called visceral muscle.<\/p>\n<p><strong>Sprain<\/strong><\/p>\n<p>The stretching or tearing of the supporting ligaments.<\/p>\n<p><strong>Strain<\/strong><\/p>\n<p>An overstretching or overexertion of a muscle or tendon.<\/p>\n<p><strong>Tendinitis<\/strong><\/p>\n<p>Inflammation of the tendon.<\/p>\n<h2>Test Yourself<\/h2>\n<div id=\"h5p-39\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-39\" class=\"h5p-iframe\" data-content-id=\"39\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Muscular System: Test Yourself\"><\/iframe><\/div>\n<\/div>\n<h2>References<\/h2>\n<p>Bureau of Labor Statistics. (2021a). Physicians and surgeons. In <em>Occupational outlook handbook<\/em>. U.S. Department of Labor. <a href=\"https:\/\/www.bls.gov\/ooh\/healthcare\/physicians-and-surgeons.htm\">https:\/\/www.bls.gov\/ooh\/healthcare\/physicians-and-surgeons.htm<\/a><\/p>\n<p>Bureau of Labor Statistics. (2021b). Massage therapists. In <em>Occupational outlook handbook<\/em>. U.S. Department of Labor. <a href=\"https:\/\/www.bls.gov\/ooh\/healthcare\/massage-therapists.htm\">https:\/\/www.bls.gov\/ooh\/healthcare\/massage-therapists.htm<\/a><\/p>\n<p>Centers for Disease Control and Prevention. (n.d.). <em>What is cerebral palsy?<\/em> <a href=\"https:\/\/www.cdc.gov\/ncbddd\/cp\/facts.html\">https:\/\/www.cdc.gov\/ncbddd\/cp\/facts.html<\/a><\/p>\n<p>CrashCourse. (2015, July 15). <em>Muscles, part 2 &#8211; organismal level: Crash course A&amp;P #22<\/em> [Video]. YouTube. <a href=\"https:\/\/youtu.be\/I80Xx7pA9hQ\">https:\/\/youtu.be\/I80Xx7pA9hQ<\/a><\/p>\n<p>National Library of Medicine. (2021). <em>Medical Subject Headings database.<\/em> National Institutes of Health, U.S. Department of Health and Human Services. <a href=\"https:\/\/www.nlm.nih.gov\/mesh\/meshhome.html\">https:\/\/www.nlm.nih.gov\/mesh\/meshhome.html<\/a><\/p>\n<p>MedlinePlus. (2021a). <em>Electromyography (EMG) and nerve conduction studies. <\/em>U.S. National Library of Medicine. <a href=\"https:\/\/medlineplus.gov\/lab-tests\/electromyography-emg-and-nerve-conduction-studies\/\">https:\/\/medlineplus.gov\/lab-tests\/electromyography-emg-and-nerve-conduction-studies<\/a><\/p>\n<p>MedlinePlus. (2021b). <em>MRI scans<\/em>. U.S. National Library of Medicine, U.S. Department of Health and Human Services. <a href=\"https:\/\/medlineplus.gov\/mriscans.html\">https:\/\/medlineplus.gov\/mriscans.html<\/a><\/p>\n<p>National Human Genome Research Institute (2013). <em>About Duchenne Muscular Dystrophy<\/em>. National Institutes of Health, U.S. Department of Health and Human Services. <a href=\"https:\/\/www.genome.gov\/Genetic-Disorders\/Duchenne-Muscular-Dystrophy\">https:\/\/www.genome.gov\/Genetic-Disorders\/Duchenne-Muscular-Dystrophy<\/a><\/p>\n<p>National Institute of Arthritis and Musculoskeletal and Skin Diseases. (n.d.). <em>Sprain vs. strain<\/em>. National Institutes of Health, U.S. Department of Health and Human Services. <a href=\"https:\/\/www.niams.nih.gov\/health-topics\/sprains-and-strains#tab-symptoms\">https:\/\/www.niams.nih.gov\/health-topics\/sprains-and-strains#tab-symptoms<\/a><\/p>\n<p>National Institute of Neurological Disorders and Stroke. (2020). <em>Carpal tunnel syndrome fact sheet<\/em>. National Institutes of Health, U.S. Department of Health and Human Services. <a href=\"https:\/\/www.ninds.nih.gov\/Disorders\/Patient-Caregiver-Education\/Fact-Sheets\/Carpal-Tunnel-Syndrome-Fact-Sheet\">https:\/\/www.ninds.nih.gov\/Disorders\/Patient-Caregiver-Education\/Fact-Sheets\/Carpal-Tunnel-Syndrome-Fact-Sheet<\/a><\/p>\n<p>Science Reference Section. (2019). <em>What is the strongest muscle in the human body?<\/em> Library of Congress. <a href=\"https:\/\/www.loc.gov\/everyday-mysteries\/biology-and-human-anatomy\/item\/what-is-the-strongest-muscle-in-the-human-body\/\">https:\/\/www.loc.gov\/everyday-mysteries\/biology-and-human-anatomy\/item\/what-is-the-strongest-muscle-in-the-human-body\/<\/a><\/p>\n<\/div>\n<\/figure>\n<figure>\n<section id=\"fs-id1707953\">\n<figure>\n<section id=\"fs-id1398723\">\n<h2>Image Descriptions<\/h2>\n<p><a id=\"Figure7.1id\" href=\"\"><\/a> <strong>Figure 7.1 image description:<\/strong> The top panel shows a micrographic view of skeletal muscle. The middle panel shows a micrographic view of smooth muscle. The bottom panel shows a micrographic view of cardiac muscle. <a href=\"#Figure7.1\">[Return to Figure 7.1].<\/a><\/p>\n<p><a id=\"Figure7.2id\" href=\"\"><\/a> <strong>Figure 7.2 image description:<\/strong> The top panel shows the anterior view of the human body with the major muscles labeled. Labels read (from the top, head): occipitofrontalis (frontal belly), sternocleidomastoid, trapezius, deltoid, pectoralis minor, serratus anterior, pectoralis major, arm muscles: biceps brachii, brachialis, brachioradialis, pronator teres, flexor carpi radialis, abdominal: rectus abdominis, abdominal external oblique, lower body: tensor fasciae latae, iliopsoas, pectineus, adductor longus, sartorius, gracilis, rectus femoris, vastus lateralis, vastus medialis, fibularis longus, tibialis anterior. The bottom panel shows the posterior view of the human body with the major muscles labeled. Labels read (from the top, head, left side): epicranial aponeurosis, occipitofrontalis, splenius capitis, levator scapulae, rhombus, trapezius, supraspinatus, teres minor, infraspinatus, teres major, triceps brachii, serratus posterior inferior, external oblique, lower body: gluteus medius, gluteus maximus, semimembranosus, peroneus longus, tibialis posterior, (right side, from top) trapezius, deltoid, latissimus dorsi, arm: brachioradialis, extensor carpi radialis, extensor digitorum, extensor carpi ulnaris, flexor carpi ulnaris, lower body: gluteus minimus, gemellus muscles, biceps femoris, semitendinosus, gracilis, gastrocnemius, soleus. <a href=\"#Figure7.2\">[Return to Figure 7.2].<\/a><\/p>\n<div class=\"textbox shaded\">Unless otherwise indicated, this chapter contains material adapted from <a href=\"https:\/\/openstax.org\/books\/anatomy-and-physiology\/pages\/1-introduction\"><em>Anatomy and Physiology<\/em><\/a> (on <a href=\"https:\/\/openstax.org\/\">OpenStax<\/a>), by Betts et al. and is used under a <a href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY 4.0 international license<\/a>. Download and access this book for free at <a href=\"https:\/\/openstax.org\/books\/anatomy-and-physiology\/pages\/1-introduction\">https:\/\/openstax.org\/books\/anatomy-and-physiology\/pages\/1-introduction<\/a>.<\/div>\n<p>&nbsp;<\/p>\n<\/section>\n<\/figure>\n<\/section>\n<\/figure>\n<div class=\"glossary\"><span class=\"screen-reader-text\" id=\"definition\">definition<\/span><template id=\"term_73_575\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_73_575\"><div tabindex=\"-1\"><p>The muscles responsible for voluntary muscle movement; also called striated muscle (Betts et al., 2013)<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_73_576\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_73_576\"><div tabindex=\"-1\"><p>Involuntary and found only in the heart. Highly coordinated contractions pump blood into the vessels of the circulatory system (Betts et al., 2013)<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_73_577\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_73_577\"><div tabindex=\"-1\"><p>The muscles responsible for involuntary muscle movement; also called visceral or non-striated muscle (Betts et al., 2013)<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_73_349\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_73_349\"><div tabindex=\"-1\"><p>The state of steady internal conditions maintained by living things (Betts et al., 2013)<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_73_553\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_73_553\"><div tabindex=\"-1\"><p>In opposition to each other (Betts et al., 2013)<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_73_552\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_73_552\"><div tabindex=\"-1\"><p>naming conventions<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><\/div>","protected":false},"author":32,"menu_order":7,"template":"","meta":{"pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"class_list":["post-73","chapter","type-chapter","status-publish","hentry"],"part":19,"_links":{"self":[{"href":"https:\/\/pressbooks.ccconline.org\/acchpr1040\/wp-json\/pressbooks\/v2\/chapters\/73","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pressbooks.ccconline.org\/acchpr1040\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/pressbooks.ccconline.org\/acchpr1040\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/pressbooks.ccconline.org\/acchpr1040\/wp-json\/wp\/v2\/users\/32"}],"version-history":[{"count":3,"href":"https:\/\/pressbooks.ccconline.org\/acchpr1040\/wp-json\/pressbooks\/v2\/chapters\/73\/revisions"}],"predecessor-version":[{"id":1500,"href":"https:\/\/pressbooks.ccconline.org\/acchpr1040\/wp-json\/pressbooks\/v2\/chapters\/73\/revisions\/1500"}],"part":[{"href":"https:\/\/pressbooks.ccconline.org\/acchpr1040\/wp-json\/pressbooks\/v2\/parts\/19"}],"metadata":[{"href":"https:\/\/pressbooks.ccconline.org\/acchpr1040\/wp-json\/pressbooks\/v2\/chapters\/73\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/pressbooks.ccconline.org\/acchpr1040\/wp-json\/wp\/v2\/media?parent=73"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/pressbooks.ccconline.org\/acchpr1040\/wp-json\/pressbooks\/v2\/chapter-type?post=73"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/pressbooks.ccconline.org\/acchpr1040\/wp-json\/wp\/v2\/contributor?post=73"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/pressbooks.ccconline.org\/acchpr1040\/wp-json\/wp\/v2\/license?post=73"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}