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Neuro retake
retake final
Question | Answer |
---|---|
the ANS is responsible for? | regulation of circulation, respiration, digestion, metabolism, secretion, body temperature & reproduction |
control ctr of ANS is | in hypothalamus & brain stem |
ANS is composed of.... | motor neurons located w/in spinal nerves that innervate smooth muscle, cardiac muscle & glands (also called effectors or target nerves) |
ANS divided into what 2 divisions? | sympathetic & parasympathetic |
parasympathetic & sympathetic innervate & travel how? | internal organs, use a two-neuron pathway & one ganglion impulse conduction & function automatically |
how is auto regulation achieved for symp & parasymp? | by intergrating info from peripheral afferents w/info from recpetors w/in CNS |
what provides the connection from the CNS to the autonomic efferent organs? | the two neuron pathway (pre & post ganglionic) |
where are cell bodies of the preganglionic neurons found? | w/in the brain or spinal cord |
how does the connection happen? | myelinated axons exit the CNS & synapse w/collections of postganglionic cell bodies, unmyelinated axons from the postganglionic neurons ultimately innervate the effector organs |
where do the sympathetic fibers of the ANS arise from? | thoracic & lumbar portions of the spinal cord |
where do axons of reganglionic neurons terminate? | either the sympathetic chain or the prevertebral ganglia located in the abdomen. |
what is the response of sympathetic division? | assists the individual in responding to stessful situations, "fight or flight". |
how does the symp division help the body prepare to cope w/perceived stimulus? | by maintaining an optimal blood supply |
body's response to activation of symph system | release of norepinephrine, major neurotransmitter causes vasoconstriction, heart rate & BP inc, blood flow to mm's increased by diverting fro gastrointenstinal tract |
role of the parasympathetic? | maintain vital bodily functions or homeeostasis |
where does the parasymp receive info from? | brain stem, cranial nerves III, VII, IX, X & lower sacral segments of spinal cord |
vagus nerve is parasympathetic preganglionic nerve or postganglionic? | parasym preganglionic |
motor fibers w/in vagus nerve innervate.... | myocardium & smooth muscle of lungs & digestive tract |
from which nerve do the motor fibers come from that innervate the myocardium & smooth muscle fibers of lungs & digestive tract? | vagus nerve |
activation of the vagus nerve does what? | can produce bradycardia, decrease force of cardia mm contraction bronchoconstriction, inc mucus production, inc peristalsis, inc glandular secretions. |
efferent activation of hte sacral components result in? | emptying of the bowels and bladder & arousal of sexual organs. |
what is responsible for sending nervous system impulses to effector cells in the parasypm division? | acetylcholine (ACH), chemical transmitter |
what is used for both divisions at the preganglionic synapse & to dilate arterioles? | acetylcholine |
activation of the parasympathetic division produces vasoconstriction or vasodilation? | vasodilation |
when a person is calm, the parasymp activity increases or decreases heart rate & blood pressure and does what to the gastrointestinal activity? | decreases HR & BP, returns to normal the gastrointestinal |
what regulates functions of digestion and medulla which controls heart & respiration rates? | hypothalamus |
cells w/in the brain completely depend on continuous supply of blood for ____________? | glucose & oxygen |
what do the neurons in the brain need to carry out glycolysis to store glycogen? | constant supply of blood |
cerebrovascular anatomy is the basis for understanding the...... | clinical manifistations, diagnosis & mangement of pts who have sustained cerebrovascular accidents and TBI |
all arteries to the brain arise from? | aortic arch |
first major arteries ascending anteriorly & laterally w/in neck are? | common carotid arteries |
common carotid arteries supply ............ | bulk of cerebrum with circulation |
what arteries supply the face? | external carotid arteries |
what arteries enter the cranium and supply the cerebral hemisphere, frontal lobe, parietal lobe & parts of temporal lobe, optic nerves & retina? | internal carotids |
if a neuron dies due to lack of oxygen, can it regenerate? | no |
effect of high levels of glutamate has what effect on neurons? | toxic & promote cell death, facilitate calcium release which produces calcium dependant digestive enzymes, cellular edema, cell injury & death |
changes w/in a cell happen how? | evident 12-24 hrs, 24-36 hrs become soft & edematous, liquefaction & cavitation begin, necrotic tissue converts to cyst infarct retracts, cystic cavity surrounded by glial scar, neurons are not replaced, orig function of area lost |
common causes of peripheral nerve injuries.... | stretching, laceration, compression, traction, disease, chemical toxicity, nutritional deficiencies. |
what is the response of peripheral nerve injury? | cell body destroyed > regeneration is not possible, axon undergoes necrosis distal to the site of injury, myelin sheath begins to pull away, Schwann cells phagocytize the area, producing wallerian degeneration. |
if damage to the peripheral nerve is not too significant and occurs only to the axon, is regeneration possible? | yes, axonal sprouting from the proximal end of damaged axon can occur |
what has to occur for a return of function? and what happens if that does not occur? | to have return of function, axon must grow & reinnervate the appropriate mm. if not, degeneration of axonal sprout |
what determines the rate of recovery from a peripheral nerve injury? | age of patient and distance betw lesion & destination of the regenerating nerve fibers. |
damage to the corticospinal tract from its origin in the frontal lobe to its end win the spinal cord is classified as what type of injury? | upper motor neuron injury |
if a patient presents with spasticity ( increased resistance to passive stretch), hpyerreflexia, the presence of a Babinski sign, and possible clonus, indication of? | upper motor neuron injury |
a repetitive stretch reflex that is elicited by passive dorsiflexion of the ankle or passive wrist extension is? | clonus |
a lower motor neuron injury occurs where? | anterior horn cell, motor nerve cells of the brain stem, spinal root or spinal nerve |
patient presents with flaccidity, marked atrophy, mm fasciculations & hyporeflexia, indication of? | lower motor neuron injury |
what is the function of white matter? | white matter is compolese of myelinated axons that carry info away from cell bodies |
what are some of the primary functions of the parietal lobe? | sensory processing, perception & short-term memory |
what is Broca's aphasia? | inability to perform motor components necessary for speech. pt may experience weakness of the lips & tongue mm |
primary function of the thalamus? | central relay station for sensory impulses traveling from other parts of the body & brain to the cerebrum. motor information received from the basal ganglia & cerebellum is transmitted to the motor cortex thru the thalamus |
primary function of the corticospinal tract | primary motor pathway |
what is an anterior horn cell? and where are they located | located w/in gray matter of spinal cord. send axons out thru ventral root that eventually become preripheral nerves that innervate mm fibers |
PNS? | divided into somatic & autonomic division |
most common site of cerebral infarction? | middle cerebral artery |
what are clinical signs of upper motor neuron injury? | spasticity, hyperreflexia, presence of Babinski sign & possibly clonus |
somatic nervous system | under conscius control & responsible for skeletal mm contraction |
autonomic nervous system | involuntary system that functions to maintain homeostasis or optimal internal environment |