E.+Central+Nervous+System


 * __ Central Nervous System __**

__ Application __
==== Meagan-This has been the most interesting unit for me so far. I am interested in how the central nervous system, CNS, works because I want to work with clients who have damage to the brain. I think it is really amazing how the different lobes of our brains control different aspects of how we function and how we interpret different stimulus. As an OTA, I will have to understand what part of the brain controls what to help focus on what to work on with the client. If the client can not comprehend or assemble words, I will know that the client is likely having difficulties with Wernicke's Area in the temporal lobe. I also find memory facinating because it is so important to many people and without it, individuals recall minimal information. As an OTA working with an individual with memory deficits, I need to understand the differences in short-term, long-term, non-declarative, and declarative memory so I can focus my treatment session on ways to help the individual with their memory deficits. ====

==== Kalli - The central nervous system, or CNS, is probably the most important system in our body because it has a very important part in every other system. Some of my clients may very well suffer from a stroke and lose many of their functions. One function most commonly seen damaged is the frontal lobe which contains the motor cortices. These motor cortices, located on the precentral gyrus, are in charge of the voluntary movement of the skeletal muscle movements. As these cortices are damaged, one may lose partial or complete control of their movements on one, if not both sides of their body. As an OTA, I would be the one to help a person to regain function in the motor cortices and move their skeletal muscles. Any type of CNS problem would most likely lead to problems in another area of the body, so knowing as much about the central nervous system as possible will help me out in the long run. ====

Christine- As nurses we deal with the central nervous system everyday. We are always making sure that this system is intact. One disease that we will deal with is Alzheimer's disease. In the Fundamentals of Physiology book it says that Alzheimer's disease is (1) a loss of neurons in the hippocampus or cerebral cortex (2) an accumulation of proteins forming nerofibrillar tangles or (3) an accumulation of of proteins called senile plaques. When I was interning the other day at the clinic an elderly woman was becoming concerned with her memory so we did a simple test on her to see if she showed signs of Alzheimer's or dementia. The first few questions were basic like what day it was, the month, the year, the season, and where she was. We then asked her to repeat three words to us. We then asked her to do a few more tasks and then we asked her to repeat those three words back to us. We then wrote "close your eyes" and the patient is suppose to be able to follow your commands. She also had to draw two pentagons that were already drawn out. The nurse that I was working with said that patients with Alzheimer's or dementia would often revisit the old times when asked what year it was, would not be able to repeat the three words or remember them at all, would not be able to follow commands and would just get frustrated when asked to draw the picture. I thought this test was a very good and simple test to test our central nervous system !

1.There are three major regions of the brain- forebrain, midbrain, and hindbrain.
The **// forebrain //** is divided into two divisions: the telencephalon (includes the cerebrum) and the diencephalon (includes the thalamus and hypothalamus).

__Telencephalon__- Cerebrum is the largest part of the brain comprising 80%. The cerebrum is divided into the left and right cerebral hemispheres. The left and right hemispheres are connected by the corpus callosom, which is a tract of axons. Deep grooves called sulci are in between convolutions called gyri.

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__Diencephalon__- The thalamus receives all **sensory** information for the cerebral cortex and relays information to the appropriate area of cortex. The hypothalamus is responsible for motivational behavior (hunger, thirst, body temperature), emotions (anger, fear, pleasure), neural control of pituitary hormone release, and control of circadian rhythms.

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The **// midbrain //**, or mesencephalon, is part of the brain stem and includes corpora quadrigemina, substantia nigra, and mesolimbic dopamine system.

__Corpora quadrigemina__- responsible for auditory and visual reflexes __Substantia nigra__- regulates activity of basal nuclei __Mesolimbic dopamine system__- involved in goal-directed behavior

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The // **hindbrain** //is part of the brain stem and divided into two divisions- metencephalon (includes pons and cerebellum) and the myelencephalon (includes the medulla oblangata). Metencephalon The pons of the hindbrain is responsible for regulation of breathing by communicating with meduall oblongata. The cerebellum is the second largest portion of the brain and receives information from proprioceptors, cordinates body movement, maintains posture and balance, and involved in learning motor skills. Picture- []

Myelencephalon

The medualla oblongata is the relay center for ascending and descending information between brain and spinal cord, principle site of decussation of information, and contains nuclei that control basal survival functions.

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Insula
Interprets olfactory information Integration of pain sensations with visceral responses Picture- []

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====The cerebrum is composed of gray matter, cell bodies, and dendrites on the outer surface and white matter, axons, forms most of the interior portion of the brain. The cerebral cortex is on the outer surface of the cerebrum which is most of the gray matter of the cerebrum. There are fives lobes located in the cerebrum to include frontal, parietal, temporal, occipital, and insula lobes. The frontal lobe is associated with reasoning, planning, parts of speech (Broca's Area), movement, emotions, and problem solving. The parietal lobe is associated with movement, orientation, recognition, and perception of stimuli. The temporal lobe is associated with perception and recognition of auditory stimuli, memory, and speech (Wernicke's Area). The occipital lobe is associated with visual processing. The insula is associated with interpretation of olfactory information and itegration of pain sensations with visceral responses.====

====The left hemisphere of the brain controls the right side of the body. This is the dominant hemisphere. The left hemispher is responsible for language and analytical ability. The right hemisphere of the brain controls the left side of the body. The right hemisphere is specialized for spatial comprehension such as reading facial expressions and maps. The different specializations of the two hemispheres is called cerebral lateralization. The left and right hemispheres communication by the corpus callosum, a tract of about 200 million axons running from one hemisphere to the other.====

3. List the brain areas that are part of the limbic system, and explain the physiological significance of the limbic system.
====The limbic system consists of a group of cerebral nuclei and axon tracts that form a ring around the brain stem. The limbic system includes the cingulate gyrus, the amygdaloid nucleus (amygdala), the hippocampus, and the septal nuclei. The physiological significance of the limbic system is involved with emotions. The hypothalamus is also apart of the limbic system and is involved in emotions. The following emotions relate to the hypothalamus: aggression, fear, sex, and goal-directed behavior.====