08a: Clinical and Misc Stuff Flashcards
In general, which CN nuclei found in midbrain?
III: Oculomotor, Edinger-Westphal
IV: Trochlear
In general, which CN nuclei found in middle pons?
V: Chief sensory and motor
In general, which CN nuclei found in lower pons?
VI: Abducens
VII: Facial
VIII: Cochlear and Vestibular
In general, which CN nuclei found in medulla?
V: Spinal trigeminal nucleus
IX/X: Nucleus ambiguous
X: Dorsal and ventral motor nuclei of vagus
XII: Hypoglossal nucleus
Descending excitatory projections from motor cortices to brainstem via (X) tract and SC via (Y) tract.
X = corticobulbar Y = corticospinal
Lower motor neurons are those that originate from:
Brainstem or SC
When lower motor neurons lose inhibitory input from (X), they do what comes naturally, which is to:
X = upper motor neurons
Continuously fire action potentials
A lower motor neuron with no inhibitory input will cause muscles to (X) and reflexes to (Y).
X = increase in contractions and tone Y = be brisk
Weakness of muscle is sign of (upper/lower) motor neuron dysfunction.
Either/both
Segmental weakness of muscle is indicative of (upper/lower) motor neuron dysfunction.
Lower
Spasticity, aka (X), is indicative of (upper/lower) motor neuron dysfunction.
X = increased tone;
Upper
Hyporeflexia or areflexia is indicative of (upper/lower) motor neuron dysfunction.
Lower
Flaccidity is indicative of (upper/lower) motor neuron dysfunction.
Lower
Fasciculations is indicative of (upper/lower) motor neuron dysfunction.
Lower
T/F: You’d see muscle atrophy in both upper and lower motor neuron dysfunction.
False - likely not upper
As concentration of extracellular sodium decreases, the action potential curve changes in which way(s)? List the factors contributing to this change.
- E(Na) decreases (lower amplitude)
2. DF(Na) decreases (smaller upward slope/slower depolarization)
Ouabain is a specific inhibitor of:
Na/K pump
T/F: At the peak of the action potential the driving force on Na+ ions is
0.
False
T/F: During the overshoot of the action potential there is a slight excess
of positive charge on the inside of the membrane.
True
T/F: At the resting potential, the current due to K+ ions is larger than that due to all other ions combined.
False
Around what voltage does relative refractory period begin?
Threshold (-55 mV or so)
In hyperkalemic periodic paralysis (HPP), there is an issue in:
Na channel inactivation
T/F: At adrenergic nerve endings (varicosities), acetylcholine acts to increase norepinephrine (NE) release.
False
Autonomic nervous system has (nicotinic/muscarinic) ACh receptors.
Both
