List the vagal nuclei.
What is the function of nucleus solitarius and which CN are involved?
Visceral sensory information (eg, taste, baroreceptors, gut distention) - CN VII, IX, X
What is the function of nucleus ambiguus?
Motor innervation of pharynx, larynx, upper esophagus (eg, swallowing palate elevation) - CN XI, X, XI (cranial portion)
What is the function of the dorsal motor nucleus?
Sends autonomic (parasympathetic) fibers to heart, lungs, upper GI - CN X
List the 5 cranial nerve reflexes.
What are the afferent and efferent components of the corneal reflex?
A - V1 ophthalmic (nasociliary branch)
E - VII (temporal branch - orbicularis oculi)
What are the afferent and efferent components of the lacrimation reflex?
A - V1 (loss of reflex does not preclude emotional tears)
E - VII
What are the afferent and efferent components of the jaw jerk?
A - V3 (sensory - muscle spindle from masseter)
E - V3 (motor - masseter)
What are the afferent and efferent components of the pupillary reflex?
A - II
E - III
What are the afferent and efferent components of the gag reflex?
A - IX
E - X
What are the muscles of mastication, their function, and innervation?
3 muscles close the jaw - masseter, temporalis, medial pterygoid (M’s munch)
1 muscle opens the jaw - lateral ptyergoid (lateral lowers)
All are innervated by V3
How many pairs of spinal nerves are there?
31 pairs (8cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal)
Where do the spinal nerves exit?
C1-C7 exit above the corresponding vertebra
C8 exists below C7 and above T1
All others - exit below
Where is a lumbar puncture usually performed and why?
L3-L4 or L4-L5 (level of cauda equina)
Spinal cord ends at lower border of L1-L2; subarachnoid space (contains CSF) extends to lower border of S2
Goal - obtain CSF without damaging the spinal cord
List the ascending tracts of the spinal cord.
2. Spinothalamic
List the descending tracts of the spinal cord.
What is the function of the ascending tracts of the spinal cord?
What is the function of the descending tract of the spinal cord?
Voluntary movement
Describe the dorsal column pathway.
Describe the spinothalamic tract.
Describe the lateral corticospinal tract.
List the clinical reflexes and what they test.
Why might primitive reflexes re-emerge in adults?
Frontal lobe lesion (frontal lobe normally inhibits them)
What is the moro reflex?
Abduct/extend arms when started, and then draw together (“Han on for life”)