See the causes and symptoms of some central nervous system disorders.
The central nervous system is made up of the brain and spine.
There are three specific functions that it has.
Nerve impulses from external and internal stimuli travel to the central nervous system.
Consider the events that occur when a person raises a glass to their lips.
Continuous sensory input from the eyes and hand informs the CNS of the position of the glass, and the CNS continually sums up the incoming data before commanding the hand to proceed.
Integration with other sensory data can cause the CNS to command a different motion.
The CNS directs the actions of drinking after the lips detect the arrival of the glass.
The brain is enclosed by the skull and the spine is surrounded by bones.
The brain and the spine are wrapped in protective coverings.
The central canal of the spinal cord and the ventricles of the brain are where the fluid comes from.
The right cerebral hemisphere is shown.
The hemispheres are connected.
The cerebral hemispheres are divided into the right and left.
The spine is made up of a bundle of nervous tissue that extends from the base of the brain to the back of the neck.
Page 697 is composed of a central portion of gray matter and a peripheral region of white matter, according to a cross section of the spine.
There are parts of sensory and motor neurons in the gray matter.
The interneurons have long fibers that run together in bundles.
The brain and the spine are connected by these tracts.
The brain and the rest of the body are connected by a busy superhighway.
The left side of the brain controls the left side of the body while the right side controls the right side.
There are 100,000 miles of myelinated nerve fibers in the human brain.
Paralysis may be caused by an injury to the spine.
All four limbs are usually paralyzed if the injury occurs in the neck region.
Paraplegia is a condition in which the lower body may be paralyzed.
There is no cure for the disease, but some drugs are currently in clinical trials.
Integration of incoming data is carried out by the central nervous system.
The brain allows us to see, to reason, and to remember.
The brain's processes for generating higher functions are shrouded in mystery.
The largest part of the brain in humans.
The activities of the other parts of the brain are communicated with.
The third ventricle is surrounded by the diencephalon and the fourth is between the pons and cerebellum.
Cerebral hemispheres are the two halves of the cerebrum.
The opposite side of the body is controlled by each hemisphere.
The right hemisphere is associated with artistic and musical ability, emotion, spatial relationships, and pattern recognition.
The left hemisphere is better at analytical reasoning.
If there is a fire, the frontal lobes allow you to decide whether to exit via the stairs or the window.
There are four cerebral hemispheres: frontal, parietal, temporal and occipital.
There are centers for reasoning, movement, hearing, and vision in these lobes.
The is a thin layer of gray matter that covers the cerebral hemispheres.
The cerebral cortexample contains tens of billions of neurons and is the region of the brain that accounts for sensation, voluntary movement, and all the thought processes required for learning, memory, language, and speech.
There are two regions of the cerebral cortex that are of interest.
The section's size shows the precision of motor control.
The muscles of the face and hands take up a larger portion of the primary motor area than the trunk.
Sensory information from the skin and muscles arrives here.
A stroke happens when the blood supply to the brain is disrupted.
The United States has three leading causes of death.
What type of symptoms arise will be determined by the area of the brain affected by a stroke.
A stroke that affects only the motor areas of the cerebral cortex might paralyze one side of the body, while a stroke involving the Broca's area might render a stroke victim unable to speak.
According to recent studies, strokes are more common in men ages 15 through 34 than in women of the same age.
Many of the risk factors for stroke are similar to those for cardiovascular disease, so you can reduce your risk.
Masses of gray matter are located deep within the white matter of the cerebrum.
The proper muscle groups are activated or prevented by the integration of motor commands.
James Parkinson, an English surgeon, first described Parkinson disease as the "shaking palsy" in 1817.
It affects about 1 million people in the United States.
People over 60 are most likely to have the disease and those under 40 are rarely affected.
One exception is Fox.
bradykinesis, tremors, rigidity of the limbs and trunk, and impaired speech, balance, and coordination are some of the symptoms of Parkinson's disease.
The substantia nigra is a part of the forebrain that helps control voluntary movement.
There is no cure for the initial events that cause the neuron damage.
Barry Kidston was a graduate student at the University of Maryland.
He decided to make a narcotic after reading a 1947 scientific paper about it.
The drug, called MPPP, was said to be less addictive than morphine and was technically not illegal.
Kidston was successful initially and was able to achieve a satisfactory "high" by injecting himself with the compound, which he had synthesized in a makeshift lab in his parent's basement.
His luck ran out when he accidentally produced a related compound.
Kidston's speech became slurred after he injected the MPTP, and within 3 days he couldn't walk.
He dramatically improved after being treated with anti-PD drugs.
He was able to function well on medication for 2 years, but then he died from a cocaine overdose.
The loss of dopamine cells in the substantia nigra is a hallmark of Parkinson's disease.
All of them had tried new heroin that had become available on the street.
Scientists were able to demonstrate that MPTP could be used in animals such as monkeys and mice after learning that it could be used in humans.
Drugs increase dopamine.
Ldopa, which is converted into dopamine in the brain, is different from newer drugs, such as entacapone.
One of the original "frozen addicts," still serving time in prison, had this procedure done and has had a significant improvement in his condition.
The use of fetal stem cells is controversial.
Results from animal models are encouraging, and groups such as the California Institute for Regenerative Medicine.
Stem cell research is a potential cure for Parkinson's disease.
The symptoms of 15 patients were reduced by injecting ProSavin, which delivers genes for dopamine synthesis directly into the brains of patients with Parkinson's disease.
The brain's substantia nigra is dark because of a high melanin content.
This area is lighter due to the loss of these neurons.
Information about these cases can be found in Langston, J. W., and Palfreman, J.
The floor of the third ventricle.
It is an integrating center that helps regulate hunger, sleep, thirst, body temperature, and water balance.
There is gray matter in the sides and roof of the third ventricle.
Sthalamus integrates sensory input and sends it to the cerebrum.
The thalamus is often the first point of contact for sensory information.
The melatonin is produced by the pineal gland in the diencephalon.
Many people suffer from insomnia, but high levels of melatonin are a key ingredient in the "rbrownies" that are sold at convenience stores and online.
The brain stem is separated from the occipital cortex by the fourth ventricle.
The laof of the hindbrain is what it is.
Motor output from the cerebral cortex and sensory input from the ears, joints, and muscles are sent to the cerebellum.
The cerebell motor impulses by way of the brain stem to the skeletal muscleway help the cerebellum maintain posture and balance.
The muscles work together to produce smooth, coordinated movements, such as those in playing the piano or hitting a baseball.
The contains the midbrain, pons, and medulla oblongata.
The left side of the brain and the right side of the brain are connected by a relay station in the midbrain.
The medulla oblongata regulates many basic body functions.
The medulla oblongata is superior to the spinal cord because it contains tracts that move between the abrain centers.
It controls the heartbeat, breathing, swallowing, and apressure.
It has centers for vomiting, coughing, hiccuping, and swallowing.
It affects myelinated nerves in the brain.
The patient's own white blood cells attack their own cells in the central nervous system.
The most common symptoms of myelin damage are fatigue, vision problems, weakness, and numbness.
More than 400,000 people in the United States have multiplesclerosis, and about 10,000 new cases are diagnosed each year.
The reticular formation receives sensory and motor signals and sends them to the spine.
The reticular activated system.
In this way, the reticular activated system arouses the cerebrum and controls sleep.
The thalamus is used to arouse the cerebrum and cause a person to be alert.
If you want to awaken the RAS, surprise it by splashing your face with cold water, but if you want to stop it, remove visual and auditory stimuli.
A severe injury to the RAS can cause a person to be comatose, which may be impossible to recover from.
A complex group of brain structures lie just under the cortex.
The limbic system includes the hypothalamus, hippocampus, amygdala, olfactory bulb, and other nearby structures.
The limbic system is made up of higher mental functions and primitive emotions.
It explains why activities such as sexual behavior and eating seem pleasurable and why mental stress can cause high blood pressure.
Higher mental functions, such as reasoning, and more primitive feelings, such as fear and pleasure, are joined by structures deep within the cerebral hemispheres.
The hippocampus and the amygdala are important parts of the limbic system.
The hippocampus is located deep in the temporal lobe and it makes the prefrontal area aware of past experiences.
The Page 701 amygdala can cause these experiences to have emotional overtones.
The smell of smoke can be an alarm to look for fire in the house.
There is learning and memory.
Learning happens when we retain and use memories.
When we recall a phone number, the prefrontal area of the brain is active.
Some phone numbers stay in long-term memory.
Think of a phone number you know by heart, and see if you can bring it to mind without thinking about the person or place associated with the number.
There is a type of memory called skill memory.
The ability to perform motor activities, such as riding a bike or playing ice hockey, is known as skill memory.
Long-term memories that are stored in bits and pieces throughout the sensory association areas can be found in the hippocampus.
The thalamus and the cortical sensory areas are involved in fear conditioning and association with danger.
The hippocampus and amygdala are where AD patients have abnormal neurons.
There are plaques around the axons and tangles around the nucleus in these neurons.
Several genes that are associated with the development of AD have been identified.
Although there is no cure for AD, most of the drugs that are currently approved to treat symptoms of AD are cholinesterase inhibitors, which increase the levels of acetylcholine in the AD patient's brain.