Neuro Dysfunction II - B

olanjones's version from 2016-03-23 14:53

Section 1

Question Answer
Function of the frontal lobemotor anticipation, decision-making
Function of parietal lobesomatosensory
Function of occipital lobevision
Function of temporal lobehearing
Function of the limbic systememotion and pain control
Parts of the brain stemmidbrain, pons, medulla oblongata
Function of midbrainrelay stimuli concerning muscle movement to other brain structures
Function of ponsrelay impulses to brain centers and lower spinal nerves
Function of medullaREFLEX CENTERS for breathing, sneezing, swallowing, coughing, vomiting, vasoconstriction
Function of cerebellumcoordinating movement, equilibrium, muscle tone, proprioception
What separates the cerebral cortex from the cerebellum?the tentorium cerebelli
What is the spinal cord?continuation of the medulla, begins at foramen mangnum and ends at first and second lumbar (where it branches into cauda equine)

Section 2

Question Answer
What are the layers of the meninges?dura mater, arachnoid mater, subarachnoid space (houses CSF), pia mater
Where are bridging veins located, what do they do?Subdural space, carry blood from brain across inner layer of dura to sinus
What is the diencephalon comprised of?thalamus, hypothalamus, epithalamus, subthalamus
Function of the thalamus?switchboard from spinal cord to cerebral cortex and other parts of the brain
Function of hypothalamus?maintain homeostasis, hunger, heat, hormones
Function of basal ganglia?balancing acetylcholine and dopamine to smooth, coordinated voluntary movement
Manifestations of injury above tentorium(supratentorial) changes in arousal due to changes in cerebral cortex
Manifestations of injurty below tentorium(sub or intratentorial) cerebellar or brainstem injury, changes in reticular activating system
Basic principles of neurologic dysfunctionneurons have limited capacity for repair and regeneration (does not happen if cell body destroyed, some axons may regenerate in PNS)

Section 3

Question Answer
What is the most important indicator of brain function?Level of Consciousness (arousal, content of thought)
Levels of consciousness (descending)fully conscious, confusion, disorientation, lethargy, obtundation, stupor, coma
Effects of mild brain hypoxia on pupillary responsewiden and respond sluggishly to light
Effects of severe brain ischemia on pupillary responsewidely dilated and “fixed” no light response
Describe decorticate posturing motor responseflexion and adduction of upper extremities, wrists, and fingers (cortical damage above the midbrain)
Describe decerebrate posturingfixed extension of upper and lower extremities (severe injury at/below midbrain)

Section 4

Question Answer
What is a critical factor in determining the neuronal cell fate after injury?degree of ATP depletion
What result does brain ischemia have?immediate neurologic dysfunction due to inability of neurons to generate ATP
What occurs 5-10 minutes after neurons are oxygen deprived?irreversible brain damage
What 2 cellular energy failure mechanisms cause brain cell death?anaerobic metabolism, deterioration of ion gradients
How does anaerobic metabolism cause brain damage?produces lactate, H+ leads to cellular acidosis, changes ion gradient, anoxic depolarization causes K+ to leave the cell, Na+, Cl-, Ca++ enter cell-> death
How does excessive glutamate cause brain damage?glutamate stimulates nearby neurons, uptake of Ca++ -> Ca++ overload injury (cytotoxic edema and swelling)
How does NMDA receptor activation cause brain damage?stimulates nitric oxide production in neurons, increases production of reactive nitrogen that functions as free radicals

Section 5

Question Answer
How does reperfusion injury cause brain damage?O2 reentering cell produces free radicals, lipid peroxidation of membrane forms arachidonic acid -> yields more O2 free radicals, inflammation mediators
What dangers do abnormal autoregulation pose to the brain?interference with vessel dilation leads to ischemia; impaired vasoconstriction leads to hyperperfusion and edema
How does hypoxia injure cells?causes ATP depletion -> increased Na+ in cell -> edema -> lysis (decreased pH from anaerobic metabolism damages cell structures)
How does ischemia cause brain damage?decreased energy delivery, damage to bv (vasomotor paralysis, vasoconstriction), changes in blood (desat, clots, sludging)
What % of cardiac output and O2 does the brain require?1/6 of cardiac output, 20% of O2 consumption