{"id":4738,"date":"2019-06-24T14:41:05","date_gmt":"2019-06-24T14:41:05","guid":{"rendered":"https:\/\/pressbooks.ccconline.org\/acchumanbio\/chapter\/9-7-case-study-conclusion-under-pressure-3\/"},"modified":"2023-11-30T18:49:40","modified_gmt":"2023-11-30T18:49:40","slug":"9-7-case-study-conclusion-under-pressure-3","status":"publish","type":"chapter","link":"https:\/\/pressbooks.ccconline.org\/acchumanbio\/chapter\/9-7-case-study-conclusion-under-pressure-3\/","title":{"raw":"7.9 Case Study Conclusion: Under Pressure","rendered":"7.9 Case Study Conclusion: Under Pressure"},"content":{"raw":" \r\n
\r\n\r\n[caption id=\"attachment_2974\" align=\"alignnone\" width=\"993\"]\"\" Figure 7.9.1 Meninges: Dura Mater, Arachnoid, and Pia Mater.<\/em>[\/caption]\r\n\r\n<\/div>\r\nAs you learned in this chapter, the human body consists of many complex systems that normally work together efficiently \u2014 like a well-oiled machine \u2014 to carry out life\u2019s functions. For example, the image above (Figure 7.9.1) illustrates how the brain and spinal cord are protected by layers of membrane called meninges and fluid that flows between the meninges and in spaces called ventricles inside the brain. This fluid is called [pb_glossary id=\"5939\"]cerebrospinal fluid[\/pb_glossary], and as you have learned, one of its important functions is to cushion and protect the brain and spinal cord, which make up most of the [pb_glossary id=\"5933\"]central nervous system[\/pb_glossary] (CNS). Additionally, cerebrospinal fluid circulates nutrients and removes waste products from the CNS. Cerebrospinal fluid is produced continually in the ventricles, circulates throughout the CNS, and is then reabsorbed by the bloodstream. If too much cerebrospinal fluid is produced, its flow is blocked, or not enough is reabsorbed, the system becomes out of balance and it can build up in the ventricles. This causes an enlargement of the ventricles called hydrocephalus that can put pressure on the brain, resulting in the types of neurological problems that former professional football player Jayson, described in the beginning of this chapter, is suffering from.\r\n\r\nRecall that Jayson\u2019s symptoms included loss of bladder control, memory loss, and difficulty walking. The cause of his symptoms was not immediately clear, although his doctors suspected that it related to the nervous system, since the nervous system acts as the control centre of the body, controlling and regulating many other organ systems. Jayson\u2019s memory loss directly implicated the brain's involvement, since that is the site of thoughts and memory. The urinary system is also controlled in part by the nervous system, so the inability to hold urine appropriately can also be a sign of a neurological issue. Jayson\u2019s trouble walking involved the muscular system, which works alongside the skeletal system to enable movement of the limbs. In turn, the contraction of muscles is regulated by the nervous system. You can see why a problem in the nervous system can cause a variety of different symptoms by affecting multiple organ systems in the human body.\r\n\r\nTo try to find the exact cause of Jayson\u2019s symptoms, his doctors performed a lumbar puncture (or spinal tap), which is the removal of some cerebrospinal fluid through a needle inserted into the lower part of the spinal canal. They then analyzed Jayson\u2019s cerebrospinal fluid for the presence of pathogens (such as bacteria) to determine whether an infection was the cause of his neurological symptoms. When no evidence of infection was found, they used an MRI to observe the structures of his brain. This is when they discovered his enlarged ventricles, which are a hallmark of hydrocephalus.\r\n\r\nTo treat Jayson\u2019s hydrocephalus, a surgeon implanted a device called a shunt in his brain to remove the excess fluid. An illustration of a brain shunt is shown in Figure 9.7.2 . One side of the shunt consists of a small tube, called a catheter, which was inserted into Jayson\u2019s ventricles. Excess cerebrospinal fluid is then drained through a one-way valve to the other end of the shunt, which was threaded under his skin to his abdominal cavity, where the fluid is released and can be reabsorbed by the bloodstream.\r\n\r\n[caption id=\"attachment_2976\" align=\"aligncenter\" width=\"400\"]\"\" Figure 7.9.2 An illustration of a brain shunt.<\/em>[\/caption]\r\n\r\nImplantation of a shunt is the most common way to treat hydrocephalus, and for some people, it can allow them to recover almost completely. However, there can be complications associated with a brain shunt. The shunt can have mechanical problems or cause an infection. Also, the rate of draining must be carefully monitored and adjusted to balance the rate of cerebrospinal fluid removal with the rate of its production. If it is drained too fast, it is called overdraining, and if it is drained too slowly, it is called underdraining. In the case of underdraining, the pressure on the brain and associated neurological symptoms will persist. In the case of overdraining, the ventricles can collapse, which can cause serious problems, such as the tearing of blood vessels and hemorrhaging. To avoid these problems, some shunts have an adjustable pressure valve, where the rate of draining can be adjusted by placing a special magnet over the scalp. You can see how the proper balance between cerebrospinal fluid production and removal is so critical \u2013 both in the causes of hydrocephalus and in its treatment.\r\n\r\nIn what other ways does your body regulate balance, or maintain a state of homeostasis? In this chapter you learned about the feedback loops that keep body temperature and blood glucose within normal ranges. Other important examples of homeostasis in the human body are the regulation of the pH in the blood and the balance of water in the body. You will learn more about homeostasis in different body systems in the coming chapters.\r\n\r\nThanks to Jayson\u2019s shunt, his symptoms are starting to improve, but he has not fully recovered. Time may tell whether the removal of the excess cerebrospinal fluid from his ventricles will eventually allow him to recover normal functioning or whether permanent damage to his nervous system has already been done. The flow of cerebrospinal fluid might seem simple, but when it gets out of balance, it can easily wreak havoc on multiple organ systems because of the intricate interconnectedness of the systems within the human \u201cmachine.\"\r\n\r\nTo learn more about hydrocephalus and its treatment, watch this video from Boston Children's Hospital:\r\n\r\nhttps:\/\/www.youtube.com\/watch?v=bHD8zYImKqA\r\n

Hydrocephalus and its treatment | Boston Children\u2019s Hospital, 2011.<\/p>\r\n \r\n

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Chapter 7 Summary<\/span><\/h1>\r\n<\/header>\r\n
\r\n\r\nThis chapter provided an overview of the organization and functioning of the human body. You learned that:\r\n