The Nervous System

1. The Nervous System By: Dylan nanez

2. What It Is • The nervous system is comprised of nerves and the specialized cells called neurons. These nerves and neurons speak to each other through impulses of electrical signals. Vertebrates, this includes humans, have a ventral and peripheral nervous system. The central nervous system consists of the brain, spinal cord, and retina. The peripheral nervous system consists of all the other singular nerves and neurons, the nerve clusters, and the nerves that connects to the central nervous system. This whole system is responsible for basically allowing you to have your five senses: touch, taste, smell, sound, and sight.

3. Getting Deeper • The very building block of the nervous system is the neuron. These cells send signals to other cells through thin fibers called axons, which cause chemicals to be released at spaces in between called synapses. A synapse gives a command to the cell and the entire process only takes a fraction of a millisecond. Sensory neurons react to physical stimuli such as light, sound and touch and send feedback to the central nervous system about the body’s surrounding environment. Motor neurons, located in the central nervous system or in peripheral nerve clusters, transmit signals to activate the muscles or glands.

4. Multiple Sclerosis • Sclerosis means hardening, so multiple sclerosis means many hardenings, which is exactly what happens. The disease affects the insulating layer of myelin on the neurons of the central nervous system. This can cause paralysis, sensory disturbances, or blindness. There are a couple of tests that can help diagnose multiple sclerosis, such as a MRI and spinal tap. Unfortunately there is no cure for this and only limited treatment of medications and physical therapy.

5. Epilepsy • Epilepsy is a brain disorder in which a person has repeated seizures over time. A seizure is the physical findings or changes in behavior that occur after an episode of abnormal electrical activity in the brain.Treatment for epilepsy may involve surgery or medication. A diagnosis would consist of an MRI. If epilepsy seizures are due to a tumor, abnormal blood vessels, or bleeding in the brain, surgery to treat these disorders may make the seizures stop. Medication to prevent seizures, called anticonvulsants, may reduce the number of future seizures.

6. Alzheimer’s Disease • Uh, I forgot…

7. Alzheimer’s Disease • Alzheimer’s is a form of dementia that worsens as time goes on, eventually leading to death. Most sufferers of Alzheimer's are 65 or older. When AD is suspected, the diagnosis is usually confirmed with tests that evaluate behavior and thinking abilities, often followed by a brain scan if available, however, available,examination of brain tissue is required for a definitive diagnosis. It’s characterized by the loss of neurons, leading to memory loss and degeneration. Treatment consists of medications to slow the progression of the disease.

8. Asperger Syndrome • Asperger’s is an autism spectrum disorder characterized by extreme social difficulties and nonverbal communications. A diagnosis is usually made between ages 4-11, where many psychological tests are performed and a parent interview. The only treatments for Asperger's would be to simply try to teach the patient what he cant naturally learn.

9. Parkinson’s Disease • Parkinson's disease (PD or, simply, Parkinson's) is the most common form of parkinsonism, a group of motor system disorders. It is a slowly progressing, degenerative disease that is usually associated with the following symptoms, all of which result from the loss of dopamine-producing brain cells. Dopamine is a substance produced in the body which has many effects, including smooth and coordinated muscle movement. So the disease would cause loss of muscle control. Diagnosis of PD is based primarily on a medical history and thorough neurological examination. Brain scans and/or lab tests may be performed to help rule out other diseases or conditions, but brain scan generally will turn out to be normal with PD. Medication is usually the treatment plan, but if needed the physician may have a surgery performed, but still no cure.