From Lecture 2/11/09 12 cranial nerves

During Lecture, we learned more on the 12 cranial nerves and their function. Cranial nerve I. is the olfactory never. It is a sensory nerve and it functions to conduct nerve impulses for the sense of smell sending afferents to the olfactory bulb. Cranial nerve II is the optic nerve. It is a sensory nerve and its specific function is sending visual afferents from the eye to the brain.  Crania nerve III is the Oculomotor. It is a mixed nerve. This means is has both sensory and motor neurons. A function for this nerve is eye movement up, down and medial. It also helps with lens accommodation and pupil constriction.  Cranial nerve IV is called Trochlear. It is also a mixed nerve. It helps with eye movements down and lateral and has afferents from muscle receptors. Cranial nerve V is called Trigeminal. It is a mixed nerve. One function is to help with chewing.  Cranial nerve VI is called Abducens with is a motor nerve and it helps with lateral eye movements.  Cranial nerve VII is called Facial. It is a mixed nerve. One function is to stimulate salivary and tear glands. Cranial nerve VIII is called Vestibulocochlear. Is is a sensory nerve and its specific function is hearing and balance. Cranial nerve IX is called Glossopharyngeal. It is a mixed nerve. It also helps stimulate salivary glands. Help functions is swallowing muscles in the pharynx. Also taste from posterior 1/3 of tongue and blood pressure receptors.  Cranial nerve X is called vagus and is also a mixed nerve. Function/controls soft palate, pharynx, heart and digestive organs. Sensation from ear canal, diaphragm, abdominal and chest vesceral organs. Cranial nerve XI is called Accessor and is a motor nerve and helps control muscles of palate, pharynx, larynx, and some neck and shoulder muscles. The last of the 12 cranial nerves is Cranial XII, also known as Hypoglossal. It is a motor nerve and helps with tongue movement.

After learning about the nerves that help with eye movements, I began wondering why some people have one eye that is weaker/slower than the other.  I have worn glasses for quite a few years. One of the things my eye Doctor told me was that my left eye is weaker than the other and if I stare at something and look from left to right, the left eye takes a second to catch up.

I did some research on weak eye muscles in one eye. While looking at different website, I came across a term I haven't heard before. It is called: Amblyopia.  It is another name for Lazy eye. It occurs when one eye develops differently than the other eye. As a result one eye is weaker than the other. Sometimes a difference in focusing ability causes one eye to be used more often. Other times, misalignment of the eyes causes one of the eyes to shut off to avoid double vision. Regardless of the cause, the result is a weakened, or amblyopic, eye.

From lecture 2/4/09: Thalamus and Hypothalamus

During Lecture and studying at home for our upcoming test, I learned the functions of the thalamus and hypothalamus.  

The thalamus relays almost all the sensory input to the cerebral cortex. It provides crude perception of touch, pressure, pain and temperature. The thalamus also includes nuclei involved in movement, planning and control.

The Hypothalamus controls and integrates activities of the autonomic nervous system and pituitary gland. It also regulates emotional and behavioral patterns and circadian rhythms of daily living.  It also controls body temperature, regulates eating and drinking, helps maintain the waking state and establishing patterns of sleep. The Hypothalamus also produces the hormones oxytocin and antidiuretic hormone.

While learning about the hypothalamus, I also Learned that it is part of our Limbic system.  Our Limbic system is sometimes referred to as , "the emotional brain". It plays a primary role in a range of emotions, including pain, pleasure, docility, affection and anger.

If the hypothalamus/limbic controls our emotions, behavior and memory, I wonder what makes some people more emotional then others.  I was interested to learn that the amygdala which is one of the basal nuclei of the cerebrum, produces a behavioral pattern called rage. It is thought to be the negative aspect of our emotions. It was then discussed in class that there have been thoughts of removing this part of the brain to see how it affects criminals, people in jail, etc.   I wanted to know more about this idea and if anyone has ever tried it. I decided to do some research.  In the Handbook of Psychological Approaches by Bincent B. Van Hasselt and Michel Hersen, I learned that the most common symptoms of amygdala removal include placidity and an absence of fear, rage, aggression, hypersexuality, hyperorality and social initiation. Based on these observations, amygdalectomy, or surgical removal of the amygdala, has been performed in over 500 cases across several countries for the treatment of violent criminals. This surgery has been demonstrated to be adequately effective in reducing aggressive behavior, with a success rate of 75 to 85%. This surgery in not favored in the United States as of now. 

After reading this, I wondered what damage to the Hypothalamus would cause. Weight regulation, and sugar and fat metabolism are related to the hypothalamic processes. Disruption in the functioning of, or destruction in this area causes an imbalance in drive states resulting in such symptoms as anorexia. Under the same article of Psychological approaches, I learned that the hypothalamus may play a role in eating disorders.  This interested me because I had a friend back in high school who had an eating disorder.  Some people thought it was due to stress and negatives in her life. I now wonder if any of her symptoms were a results of damage to her hypothalamus or Limbic system.

Week 2 The nervous system

In lecture, I have been learning just how complex the nervous system is. Although the nervous system is one of our smallest systems, it is the most complex and it controls everyting we see, feel think and do. The nervous system is responsible for all of our perceptions, memories, and movements. I learned that there are two main subdivisions of the nervous system. This includes the nentral nervous system which consists of the brain and spinal cord, and the peripheral nervous system which includes all nervous tissue outside the CNS, spinal and cranial nerves.
There are different functions of the nervous system including sensory, integrative, and motor function. In Sensory function, sensory receptors detect internal stimuli. There are sensory/afferent neurons. These neurons carry inpulses toward the CNS. With Integration, the nervous system integrates/processes sensory information recieved from afferent neurons by analyzing it, storing it and making decisions for appropriate responses. The nervous system's motor function involves responding to integration decision made by interneurons. Efferent neurons carry impulses from the brain toward the spinal cord to cranial or spinal nerves.

During Lecture, we briefly discussed some central nervous system diseases such as bipolar disease and schizophrenia. My brother in Law is 18 years old and has cerebral palsy. Cerebral palsy in also a disease of the central nervous system. I have been able to see first hand the effects of this disease but I never quite understood the cause. Discussing the complex system of the CNS in lecture has really made me want to learn more about this disease.

I googled cerebral palsy online and learned some interesting facts. Cerebral palsy is a disorder of the nervous system. Movements of the body and coordination of muscles are disturbed due to damage to specific areas of the brain that occurs during fetal development. It is caused by injuries to the cerebrum which is the largest part of the brain. It cannot be cured but through education, therapy, patients can be made to lead a productive life. My brother in law goes to physical therapy every week and I have noticed that the more he goes, the more strength he has in his legs. He wears braces on his legs that help with ambulation. I once thought this disease only affected muscular movement and coordnation. I now know that some, although not all, children with cerebral palsy are affected by mental retardation. Generally, the more severe the retardation, the more severe the disability overall.

My brother in law is one of the sweetest, most loving person that I know. Despite his disabilities, education on the disease helps his family give him a happy and close to normal life. My brother in Law has recently won some metals doing horse back riding in the special olympics in Florida which is just one of the signs that through medicine, science and education we can continue to help him and other people with Central nervous symptoms live the best quality of life as possible.

week 1 lecture- Components of the Neuron

We are currently discussing neurons and the way impulses are generated throughout our body to relay messages. We are learning the components of a neuron, it's surroundings and how they impact our daily living. I learned that neurons have a cell body, dendrites and an axon. One thing that I found interesting that is part of the make up of neurons are neuroglia. Neuroglia constitute about half the volume of the CNS. Brain tumors derived from glia, called gliomas tend to be highly malignant and to grow rapidly. About 1 1/2 years ago, my mother was diagnosed with a Brain Tumor. Prior to finding this, changes in my moms health, behavior and daily living seemed to change drastically. For about a year prior to the MRI that diagnosed my mom with a brain tumor, she experienced dizziness and feelings of being off balance on almost a daily basis. At this point, my mother was told that she had vertigo. After dealing with these symptoms for almost a year, she began to develop new symptoms. My mom began to have memory problems, forgetting even small things like pouring a cup of coffee. She seemed to be having an increase in difficulty concentrating. She also had the feeling of a band of pressure over her forehead. The type of brain Tumor that my mom was diagnosed with was an meningioma. Meningiomas affect the CNS by compressing brain tissue, nerves or associated structures causing reactive swelling in brain tissue which can block the flow of cerbrospinal fluid. My mom is doing ok and is being watched for further symptoms or growth of the tumor. Understanding the affects damage to your CNS can cause and reporting symptoms to your doctor, can help in diagnosing and treatment of CNS diseases.