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Allied Health
Nervous System
Question | Answer |
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What is a neuron? | Neuron is the medical word for nerve cell. Neurons transmit a message from one cell to the next. Neurons have a nucleus, cytoplasm ,and cell membrane. (cell body) |
What are dentrites? | Dendrites are nerve cell processes(extensions/branches) that carry impulse to cell bodies. Each neuron may have one or many dentrites. |
What is an axon? | A single axon carries impulses away from cell body. |
What is the neurilemma(myelin sheath)? | It is a covering that speed up the nerve impulse along the axon. Myelin is a fatty substance that protects the axon. |
What initiates an impulse? | A stimulus does. |
Where does the impulse travel first? | The sensory(afferent) neurons, which emerge from theskin or sense organs. The impulse comes in on it's dendrite(s) and out on the axon to the next neuron. |
What are the associative neurons (interneurons)? | They carry impulses from sensory neurons to motor neurons. |
What are motor(efferent) neurons? | They carry messages from brain or spinal cord to muscles and glands. One neuron doesnt completely touch the next. |
What is the synapse? | It is a space between neurons. Chemicals (neurotransmitters)that cross the synapse carry messages from one cell to the next nerve cell. |
What does the centra lnervous system include? | The brain and the spinal cord. |
What does the peripheral nervous system include? | The carnial nerves and the spinal nerves. It is divided into the somatic(voluntay)/skeletal; autonomic nervous system. Not conscious control (involuntary action) |
What does the autonomic system include? | parasympathetic branch- routine branch (digesting food, eating); sympathetic branch- danger response( muscles contract, heart beat increases, oxygen increased). known also as the fight-or-flight. |
The central nervous system? | Communication and coordinating system of the body, seat of intellect and reasoning, consists of the brain and spinal cord. |
What are meninges? | Tough fluid containing membrane that covers the brain and spinal cord. |
What is the dura mater? | The outermost brain covering, line that inside of the skull, tough dense fibrous connective tissue. |
What is the subdural space? | It is between dura and arachnoid. |
What is the arachnoid? | The middle layer, resembles fine cobweb(blood vessels). |
What is the subarachnoid space? | It is between arachnoid and pia mater, filled with cerebrospinal fluid- acts as a liquid shock absorber and source of nutrients for the brain. |
What is the pia mater? | It covers the brain's surface, comprised of blood vessels held together by connective tissue.(innermost) |
What are the characteristics of the brain? | 3 lb mass of soft nervous tissue, 100 billion neurons, protected by skull, three membranes called meninges, and cerebrospinal fluid, adequate blood supply is needed, brain tissue will die in 4-8 minutes without oxygen, divided into 4 major parts: |
What are the four parts of the brain? | Cerebrum, diencephalon, cerebellum, and brain stem. |
Ventricles of the brain? | There are four cerebral ventricles which are four cavities filled with cerebrospinal fluid. |
Whare are the left and right side of the brain? | Lateral ventricles. |
The third ventricle. | Behind and below the lateral ventricles. |
Fourth ventricle. | Below the 3rd ventricles, in front of the cerebellum and behind the pons and medulla oblongata. |
What are the choroid plexus? | Network of blood vessels lining the ventricles which helps in the formation of cerebrospinal fluid. |
What is the cerebrospinal fluid? | Forms and is contained in the ventricles of the brain; serves as a liquid shock absorber protecting the brain and spianl cord |
What is the blood-brain barrier? | Choroid plexus capillaries prevent substances(like drugs) from penetrating brain tissue-this makes infections, like meningitis, diffcult to cure. |
What is the lumbar puncture? | Diagnostic test that invloved the removal of CSF from sipinal canal. The needle puncture is between 3rd and 4th lumbar vertebrate. |
What is the cerebrum? (adjective is cerebral) | Largest part of the brain; divided into R and L lhemispheres by deep groove(longitudinal fissure) |
What are convolutions? | Elevated folds on the surface of the cerebrum, they increase the surface area of the brain(they are extended). |
What is the sulci? | Fissure or prooves sepearting cerebral convolutions; divided into four lobes: frontal, pariteal, occipital and temporal. |
What is the cerebral function? | Conscious thought-consciousness, mental processing, judgement, memory, reasoning, normal speech and will power. |
What is diencephalon? | LOcated between cerebrum and midbrain; composed of thalamus and hyothalmus; |
What are the vital functions of the hypothalamus? | Autonomic nervous control; Temperture control; Appetie control; Emontional state; sleep control. |
What is the cerebellum? | Located behind the pons and below the cerebrum; Second largest part of the brain; composed of two hemispheres; controls all body functions releated to skeletal muscles including: Balance and walking, and muscle tone, and coordination of muscle movements. |
What is the brainstem? | Made up of three parts: Pons, Medulla, and Midbrain. Pathway for ascending and descending tracts. |
What are pons? | In front of cerebellum , between midbrai, and medulla- contains center that controls respiration |
What is the midbrain? | Responsible for hearing and vision. |
What is the medulla oblongata? | Buld-shaped structure between pons and spinal cord, inside the cranium above foramen magnum; responsible for: heart rate, and blood pressure. |
What is the spinal cord? | Begins at foramen magnum and continues down to 2nd lumbar vertebrae; white and soft, in spinal cord; surrounded by cerebrospinal fluid, functions as-reflex center, and conduction pathway to and from the brain. |
What is the peripheral nervous system? | All of the nerves of the body and ganglia. |
What are nerves? | Bundle of nerve fibers(axons)enclosed by connective tissue; Sensory nerves carry impulses to brain and spinal cord; Motor nerves carry impulses to muscles or glands; Mixed nerves contain both sensory and motor fibers. |
What are cranial nerves? | There are 12 pairs of cranial nerves; begin in the brain; designated by number and name, -olfactory, Optic, Oculomotor, Trochlear, Trigeminal, Abducens, Facial, Vestibulocochlear, Glossopharyngeal, Vagus, Acessory, Hypoglossal. |
What are spinal nerves? | Originate at spinal cord and go through openings in vertebrae; 31 paris of spinal nerves; all are mixed nerves; named in relation to their location on the spinal cord. |
What is meningitis? | Any inflammation of the lining of the brain and spinal cord; may be bactrial or viral; Symptoms- headache, fever and stiff neck; in sever form, may lead to paralysis, coma, and death; if bacterial, may be treated with antibiotics. |
What is epilephsy? | Seizure disorder of the brain, characterized by recurring and excessive discharge from neurons; seizures believed to be result of spontaneous, uncontrolled electrical activity of neurons; cause is uncertain; victim may have hallucinations and seizures. |
What is grand mal? | Severe, convulsive seizure. |
What is petit mal? | Milder |
What is alzheimer's disease? | Progressive disease that begins with problems remembering; nerve endings in cortex of brain degenerate and block signals thatpass between nerve cells; abnormal fibers build up creating tangles; cause is unknown; |
What are the stages of alzheimer's disease? | First stage(2-4 years): invloves confusion, short-terms memory loss, anxiety, poor judgement; 2nd stage(2-10 years): increase in memory loss, diffculty recognizing people, motor problems, logic problems, and loss of social skills. |
What is the 3rd stage of alzheimer's disease? | (1-3 years): inability to recognize oneself, weight loss, seizures, mood swings and aphasia. |
What is cerebral vascular accident? | CVA or stroke. Interruption of blood and O2 to brain leading to tissue death; third leading cause of death in USA. |
What are the risk factors for CVA? | Smoking, hypertension, hear disease, and family history. |
What are the causes of CVA? | 90% caused by blood clots. Clots lodge in carotid arteries, blocking the flow of blood to the brain.; 10% caused by ruptured blood vessels in the brain. |
What are the causes of CVA? | Hemiplegia: paralysis on one side of the body, on the opposite side from the stroke. PARALYSIS:loss of power of motion or sensation. sudden, sever headache, dizziness, sudden loss of vision in one eye; APHASIS: inability to speak or dysphasia, coma, death |
What are the treatments for CVA? | Get to the hospital immediately, CT done to determine etiolgy, if a clot, treatment aimed at dissolving clot. |
What is the prevention of CVA? | If TIA's-one aspirn a day, stop smoking, exercise and lose weight, control hypertension. |