ANS and major tracts

Question 1

Describe the structure, location, and function of ascending and descending spinal cord tracts

Answer 1

tracts: dorsal white column, spinothalamic, and corticospinal

Question 2

dorsal white column pathway

Answer 2

dorsal root ganglion –> first order neuron –> medulla (decussates) –> second order neuron –> thalamus (final synapse) –> third order neuron (primary somatosensory cortex)

Question 3

spinothalamic pathways

Answer 3

dorsal root ganglion –> first order neuron –> spinal cord (decussates) –> second order neuron –> thalamus (final synapse) –> third order neuron –> primary somatosensory cortex

Question 4

corticospinal pathway

Answer 4

precentral gyrus (primary motor cortex) –> upper motor neuron –> medulla (decussation) –> ventral horn (synapse) –> lower motor neuron –> skeletal muscle

Question 5

ANS vs SNS in terms of site of origination, number of neurons involved in the pathway, effectors, receptors, and neurotransmitters

Answer 5

ANS: 2 neuron pathway (pre/postganglionic)
SNS: 1 neuron that travel all the way down

Question 6

two divisions of ANS

Answer 6

sympathetic and parasympathetic

Question 7

parasympathetic vs sympathetic

Answer 7

sympathetic: fight or flight
–> short pre, long post fibers (lateral horns)

parasympathetic: rest and digest
–>long pre, short post (brain stem/sacral)

Question 8

major components of sympathetic divisions and parasympathetic divisions

Answer 8

sympathetic: sympathetic trunk, white/gray rami communicates, splanchnic nerves

parasympathetic: cranial nerves III, VII, IX, and X, pelvic splanchnic

Question 9

different anatomical pathways through sympathetic and parasympathetic neurons

Answer 9

sympathetic (thoracic and lumbar) : think heart, and other organs

parasympathetic (cranial and sacral) : think target organs

Question 10

effects of sympathetic innervation vs parasympathetic innervation

Answer 10

sympathetic: prepares body for physical activity
–>pupil dilation, heart rate up, respiration up

parasympathetic: resting
–> pupil constriction, increase digestion/urination

Question 11

relationship between chromaffin cells in adernal medulla and sympathetic division

Answer 11

release hormones like epinephrine and norepinephrine into blood stream

Question 12

visceral reflex arcs (structure and function)

Answer 12

organ (think automatic)
S: lateral horn –> spinal nerves –> sympathetic chain –> post ganglionic fiber
P:

Question 13

cholinergic vs adrenergic receptors with respect to neurotransmitters

Answer 13

S: adernergic (norepineprine and epinephrine)
–> alpha/beta
P: cholinergic (acetylcholine)
–> nicotinic and musoxinic