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39 Cards in this Set
- Front
- Back
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What is Syringomyelia?
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A degenerative cavitation of the central canal of the spinal cord, often the result of a cord tumor.
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What are some symptoms of syringomyelia?
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neuralgia(pain along course of nerve), paraesthesia(abnormal sensations, burning, tingling, and increased sensitivity to pain), specific loss of pain and temperature sensation and paresis.
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What causes syringomyelia/
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It occurs where the fibers giving rise to the anterolateral system cross over in the center of thespinal cord. As a result of damage to crossing fibers from both sides, there is a loss of pain and temperature on both sides of the body in a segment at the level of the cord damage.
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What is AMS?
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Amyotrophic lateral sclerosis. (Lou Gherig's disease). It usually affects people between the ages of 40 -70. About 10% of cases are inherited.
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What are early symptoms of Lou Gherig's disease?
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It begins with weakness and clumsiness andprogresses to loss of muscle control over 2-5 years.
It destroys both upper and lower motor neurons. |
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How does the inherited form of AMS result?
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From a mutation in DNA coding for the enzyme superoxide dismutase(SOD) and is located on chromosome 21. SOD is involved in eliminating a free radical, known as superoxide, from the body.
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What are free radicals?
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They are molecules that readily accept electrons, which make them highly reactive. They can strip electrons from proteins, lipids or nucleic acids, thereby destroying their functions and resulting in cell dysfunction or death.
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Free radical damage has been implicated in what diseases?
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ALS, arteriosclerosis, arthritis, cancer and aging.
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What is superoxide?
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It is one of the most important and toxic free radicals. It formsas the result of O2 reacting with other free radicals.
Although O2 is critical for aerobic metabolism, it is also dangerous to tissues. |
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What does SOD do?
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It atalyzes the conversion of superoxide to H2O2, which is then converted by catalase to O2 and H2O.
If SOD is defective, superoxide is not degreaded and can destroy cells. Motor neurons are particularly sensitive to superoxide attack. |
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What s Brown-Sequard syndrome?
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A lesion of the spinal cord that destroys half the cord at a specific level(hemisection), and results in a very specific syndrome, called Brown-Seq'uard syndrome. It includes contralateral loss of pain and temperature because fibers entering the anterolateral system cross over where they enter the spinal cord, as well as ipsilateral loss of proprioception.
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What is Sydenham chorea?
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Also called St. Vitus' dance, is a disease usually associated with a toxic or an infectious disorder that apparantly causes temporary dysfunction of the corpus striatum. It usually affects children.
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What is dyskinesia?
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It involves the basal nuclei, in which unwanted superfluous movements occur. This may result in brisk, jerky purposeless movements that resemble fragments of voluntary movements.
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What is Huntingdon chorea?
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It is a dominant hereditary disorder that begins in middle life causing mental deterioration and progressive degeneration of the corpus striatum in affected individuals.
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What scerebral palsy?
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A general term referring to defects in motor function or coordination resulting from several types of brain damage.
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What is Athetosis?
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Often a feature of Cerebral palsy, and characterized by, slow, sinuous, aimless movements. When the face, neck and tongue muscles are involved, grimacing, protrusion and writhing of the tongue and difficulty in speaking andswallowing is evident.
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What is Hemiballismus?
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An uncontrolled purposeless and forceful throwing or flailing of the arm.
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What is Parkinson's disease?
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It is characterized by by muscular rigidity, loss of facial expression, trmor, a slow shuffling gait and general lack of movement.
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What causes Parkinson's disease?
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It is caused by a dysfunction in the substantia nigra.
It usually occurs after age 55 and is not contagious or inherited. A resting tremor called pill rolling is characteristic of the disease. |
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What causes the increased muscular rigidity?
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This results from defective inhibition of the basal nuclei by the substantia nigra.
In this disease, dopamine, an inhibitory neurotransmitter produced by the substantia nigra is deficient. The melanin containing cells of the substantia nigra degenerate, resulting in a loss of pigment. |
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How is Parkinson's disease treated?
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It is treated with Levodopa, a precursor of dopamine, or more effectively with Sinemet, a combination of L-dopa and carbidopa.
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What is Carbidopa?
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It is a decarboxylase inhibitor, which prevents the breakdown of L-dopa before it can reach the brain.
Dyskinesias are sometimes a side effect of levodopa. Because of this, other dopamine agaonists, such as ropinirole and pramipexole are being studied. A protein called "glial cell line derived neurotrophic factor(GDNF) has been discovered that selectively promotes the survival of dopamine secreting neurons. |
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Certain drugs can either stimulate or depress the Reticular activating system. TRUE/FALSE
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TRUE. General anaesthetics suppress this system, as do many tranquilizers. Ammonia(smelling salts) and other irritants stimulate trigeminal nerve endings in the nose.
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What is aphasia
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Absent or defective speech or language comprehension, andresults from a lesion in the language aeas of the cortex.
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What is receptive aphasia?
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(Wernicke's aphasia), which includes defective auditory and visual comprehension of language, defective naming of objects and repitition of spoken sentences is caused by a lesion in Wernicke's area.
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What is Jargon and Conduction aphasia?
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Jargon- a person may speak fluently but unintelligibly,
conduction- in which a person has poor repitition but good comprehension. These can result from a lesion in the tracts between Wernicke's and Broca's area. |
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What is Anomic aphasia?
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Caused by the isolation of Wernicke's area from the parietal or temporal association areas, is characterized by fluent but circular speech resulting from poor word finding ability.
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What is Expressive aphasia?
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(Broca's apahasia) caused by a lesion in Broca's area, is characterized by hesitant and distorted speech.
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What is Amorphosynthesis?
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A person suffering a stroke in the right parietal lobe may lose the ability to recognize faces while retaining essentially all other brain functions.
A more severe lesion can cause a person to lose the ability to identify simple objects. This is amorphosynthesis. Some people with a similar lesion in the right cerebral hemisphere may tend to ignore the left half of the world, including their bodies, and food on the left half of their plate. |
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What is Tabes dorsalis?
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This is usually a result of untreated syphilis. Tabes means wasting away, and dorsalis refers to a degeneration of the dorsal roots and dorsal columns of the spinal cord. Ataxia is a common finding.
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Alzheimer's disease is characterized by the appearance of amyloid plaqus and neurofibrillary tangles. TRUE/FALSE
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TRUE.
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What are amyloid plaques?
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They are axonal enlargements of degenerating nerve fibers, containing large amounts of, Beta-amyloid protein, and neurofibrillary tangles are filaments inside the cell bodies of dead or dying neurons.
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What is Apolipoprotein E?
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This is a protein which binds to beta amyloid protein and is known to transport cholesterol in the blood.
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Are there different forms of apolipoprotein?
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Yes.
ApoE-111 is the normal protein, and 1V is abnormal. 1V has been found in amyloid plaques and neurofibrillary tangles and has been mapped to the same region of chromosome 19 as the late onset form of A. disease. People with 2 copies of apoE-1V gene are 8 times more likely to develop the disease. |
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What is tau protein?
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Thisis another protein called tau protein, which in turn is involved in microtubule formation inside neurons. If tau is overphosphorylated, microtubules are not properly constructed anf the t proteins intertwine to form neurofibrillary tangles.
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What are gangliosides?
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Neurons contain specialized membrane lipids known as gangliosides. Lysosomes contain a variety of hydrolytic enzymes including those that digest gangliosides.
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What is Hexoseaminadase A?
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It is a lysosomal enzyme that breaks down a specific type of ganglioside called GM2 ganglioside. The gene that encodes hexoseaminadase A is called hex-A and found on chromosome 15.
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What is Tay-Sachs disease?
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A autosomal recessive enzyme disorder caused by mutations to the hex A gene.
GM2 ganglioside accumulates in cells and damages them, especially in neurons of the CNS. Hex A also breaks down gangliosides i the light sensitive cells in the eye. In the absence of this enzyme, gangliosides accumulate in these cells leading to blindness. |
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What are symptoms of te disease?
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The infant appears to develop normally, but then appears to regress, losing motor functions, exhibiting seizures, becoming blind, and retarded and eventually dying by the age of 4 or 5.
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