Chapter 7.6 Nervous System
What is the Nervous System?
A complex, highly organized system that coordinates all the activities of the body.
What is a neuron?
A nerve cell.
What is a Synapses?
The space between the axons and the ends of the dendrites.
What allows nerve impulses to pass from one neuron to another?
Neurotransmitters
What does the Myelin Sheath do?
It increases the rate of impulse transmission and insulates and maintains the axon.
What is the purpose of Sensory Nerves?
To carry messages from all parts of the body to the brain and spinal cord.
What do Motor Nerves do?
They carry messages from the brain and spinal cord to the muscles and glands.
What do Internuncial Nerves carry?
Motor and Sensory messages
What does the Central Nervous System consist of?
What two divisions of nerves does the Peripheral Nervous System consist of?
Brain and Spinal Cord
Somatic Nervous System(carries messages between CNS and the body) and Autonomic Nervous System(contains Sympathetic and Parasympathetic nervous systems, which control involuntary body functions)
What are the 6 parts of the Brain and what do they do?
Where does the spinal cord come down from and end?
The Spinal Cord comes down from the medulla oblongata and ends at the first or second vertebrae
What are Meninges?
The three membranes that cover and protect the brain and spinal cord
What are the three membranes in meninges?
True or False: The brain has four ventricles. (hollow spaces that connect with each other and the subarachnoid)
True
True or False: Cerebrospinal Fluid is colorless fluid that circulates continually through the ventricles and the subarachnoid space.
True
Cerebrospinal fluid is produced by ventricles of the brain by what special structures?
Chroid Plexuses
Does Cerebrospinal fluid remove metabolic products and wastes?
Yes
What does Cerebrospinal fluid act as to protect the brain and spinal cord?
A Shock Absorber
Does Cerebrospinal fluid carry nutrients to some parts of the brain and spinal cord?
Yes
What are the special structures called that return the cerebrospinal fluid to the blood stream?
Arachnoid Villi
What does Cerebrospinal fluid do after it is done circulating?
It gets absorbed into the blood vessels of the dura mater and is returned into the blood stream by arachnoid villi
What is the Brain?
A mass of nerve tissue well protected by membranes
What is the bone that protects the brain?
Skull or Cranium
How does the Pia Mater provide nourishment to the nerve tissue?
It is closely attached to the brain and spinal cord, and contains blood vessels that nourish the nerve tissue
True or False: The Medulla Oblongata is at the highest part of the brainstem.
False. It is located at the lowest part of the brainstem
How many pairs of cranial nerves does the somatic nervous system consist of?
12 pairs
How many spinal nerves does the somatic nervous system consist of?
31 pairs
What are some of the special senses some of the cranial nerves are responsible for?
Sight, hearing, taste, and smell.
What are the other cranial nerves responsible for?
They receive sensations like touch, pressure, pain, and temperature. They also send out impulses for involuntary muscle control.
What does the autonomic system help keep in balance and allow?
It maintains the balance in involuntary functions and allows the body to react in times of emergency.
What does the two systems (sympathetic and parasympathetic systems) work together to make happen?
They make a balanced state or homeostasis and to control involuntary body functions at proper rates.
How does the sympathetic system do to prepare the body in times of emergency?
Increasing heart rate, respiration, and blood pressure. It slows the digestive tract activity. This is called the fight or flight response.
How does the parasympathetic counteract the actions of the sympathetic system?
It slows the heart rate, lowering blood pressure, and increasing the activity of the digestive tract.
What is Amyotrophic Lateral Sclerosis or Lou Gehrig's disease?
It is a chronic, degenerative neuromuscular disease.
What are the causes and symptoms?
There is no known cause but they suspect there are genetic or viral-immune factors. Nerve cells in the CNS that control voluntary movement degenerate in resulting in atrophy or weakening in the muscle control. The symptoms are muscle weakness, abnormal reflexes, tripping, and falling, impaired hand and arm movement, and difficulty speaking or swallowing. As the disease progress its affects can result in total body paralysis. Long term affects can be losing all ability to communicate, breathe, eat, and move. But it does not affect the mind so its an active mind inside of a paralyzed body.
Whats the usual life span of a patient with this disease?
4-6 but some patients with slower progression can have 10-20 years.
What is Carpel Tunnel?
A condition that occurs when the medial nerves and tendons that pass through a canal or "tunnel" on their way from the forearm to the hands and fingers are pinched.
What are the causes and symptoms?
It is caused by repetitive movements of the wrist which causes swelling around this tunnel which puts pressure on the nerves and tendons. The symptoms are pain, muscle weakness in the and, and impaired movement.
What is the treatment?
This can be treated with anti-inflammatory medications, analgesics for pain, and splinting to immobilize the joint.
What is Cerebral palsy?
This a disturbance in voluntary muscle actions. There are three forms: Spastic, Athetoid, Atactic.
What are the causes and symptoms?
This disease is caused by brain damage, lack of oxygen to the brain, birth injuries, prenatal rubella (German measles), and infections. The symptoms are exagerated reflexes, tense muscles, contracture development, seizures, speech impairment, spasms, tremors, and in some cases mental retardation.
Can this be cured? Are there treatments?
No it can not be cured but there are some treatments to help with the affects. These can include physical, occupational, and speech therapy. There are also other treatments to help like muscle relaxants, anti-convulsion drugs, casts, braces, and/ or orthopedic surgery.
What is Cerebrovascular Accident?
A brain attack, stroke; or apoplexy, occurs when the blood flow to the brain is impaired, resulting in a lack of oxygen and a destruction of brain tissue.
What are the causes and symptoms?
It is caused by cerebral hemorrhage resulting from hypertension, an aneurysm, or a weak blood vessel; or by an occlusion, or blockage, caused by atherosclerosis or a thrombus. The symptoms vary depending on the area and amount of brain damage. Some common symptoms of an acute CVA include loss of consciousness, weakness paralysis on one side of the body, dizziness, dysphagia, visual disturbances, mental confusion, aphasia, and incontinence.
Can it be cured? Are there treatments?
There isn't a cure. The treatments are physical, occupational, and speech therapy treatment.
What is Encephalitis?
Inflammation of the brain
What are the causes and symptoms?
It is caused by a virus, bacterium, chemical agent, or as a complication of measles, chicken pox, or mumps. It is contracted by mosquito bites, because mosquitoes can carry the Encephalitis virus. The symptoms vary but may include fever, extreme weakness, vomiting, stiff neck and back, disorientation, seizures, and coma.
Can it be cured? Are there treatments?
No it can not be cured. Treatment methods include antiviral drugs, maintenance of fluids and electrolytes balance, anti-seizure medication, and monitoring of respiratory and kidney functions.
What is Epilepsy?
A brain disorder associated with abnormal electrical impulses in the neurons of the brain
What are the causes and symptoms?
The causes include brain injury, birth trauma, tumors, toxins such as lead or carbon monoxide, and infections. The symptoms include absence seizures are milder seizures in which they lose consciousness lasting several seconds. Generalized tonic-clonic are the most severe seizures are characterized by loss of consciousness lasting several minutes, convulsions accompanied by violent shaking and thrashing movement; hyper-salivation, causing the mouth to foam; and loss of bodily functions. Some individuals experience an aura such as a particular smell, ringing in the ears, visual disturbances, or tingling in the fingers and/or toes before the seizure occurs.
Can it be cured? Are there treatments?
No there is not a cure. The only treatment is anticonvulsant drugs.
What is Hydrocephalus?
An excessive accumulation of cerebrospinal fluid in the ventricles and in some cases, the subarachnoid space of the brain.
What are the cause and symptoms?
It is caused by a congenital defect, infection, or tumor that obstructs the flow of cerebrospinal fluid out of the brain. Symptoms include an abnormally enlarged head, prominent forehead, bulging eyes, irritability, distended scalp veins,and when pressure prevents proper development of the brain, retardation.
Can it be cured? Are there treatments?
There is no cure. The treatment is having a shunt surgically implanted between the ventricles and the veins, heart, or abdominal peritoneal cavity to provide for drainage of the excess fluid.
What is Meningitis?
An inflammation of the meninges of the brain and /or spinal cord.
What are the causes and symptoms?
It is caused by a bacterium, virus, fungus, or toxin such as lead or arsenic. Symptoms include high fever, headaches, back and neck pain and stiffness, nausea and vomiting, delirium, convulsions, and if untreated, coma and death.
Can it be cured? Are there treatments?
It can be cured. Treatments include antibiotics, antipyretics, anticonvulsants, and/or medications for pain and cerebral edema.
What is Multiple Sclerosis?
Is a chronic, progressive, disabling condition
What are the causes and symptoms?
It is caused by a degeneration of the myelin sheath in the CNS. The cause is unknown but genetics or a viral infection of the immune system are suspected. Early symptoms include visual disturbances such as diplopia, weakness, fatigue, poor coordination, and tingling and numbness. Later symptoms include tremors, muscle spasms, paralysis, speech impairment, emotional swings, and incontinence occur.
Can it be cured? Are there treatments?
There is no cure. Treatment methods such as physical therapy, muscle relaxants, steroids, and psychological counseling are used to maintain functional ability as long as possible.
What is Neuralgia?
This is nerve pain.
What are the causes and symptoms?
This is caused by immflamation, pressure, toxins, and other diseases.
What are the treatments?
The treatments help what is causing the pain.
WHat is Paralysis?
This usually results from brain or spinal cord damage that destroys neurons and results in a loss off funsction and sensation below the level of injury.
What are the three types?
Hemiplegia is paralysis of one side o the body and is caused bya tumor, injury, or CVA. The second type is paraplegia is in the lower extremities and is caused by a spinal cord injury. The third type is Quadraplegia. This is paralysis of the legs, arms, and body below the spinal cord.
Is there a way to cure it?
There is no known cure although they are working on how to repair the spinal cord damage. Treatment methods are supportive like physical and occupational therapy.