McWhorter - Visceral Sensory and Visceromotor I&II

Question 1

what is responsible for difficulty in localizing visceral pain?

Answer 1

receptor # and receptor field

-refer to somatic body structure

Question 2

where do primary visceral afferent fibers synapse?

Answer 2

solitary nucleus in medulla

Question 3

location of osmoreceptors and internal thermal receptors

Answer 3

hypothalamus

Question 4

parasympathetic nerve fibers**

Answer 4

carry info. originating from physiologic receptors (innocuous input)

Question 5

sympathetic nerve fibers**

Answer 5

carry input from nociceptors

Question 6

what makes up the anterolateral system?

Answer 6

spinoreticular fibers and spinothalamic fibers

Question 7

which region of the brain do you perceive visceral pain?

Answer 7

insula and parietal operculum

Question 8

what are the 2 ways visceral nociceptive stimuli can reach the cortex?

Answer 8

1. direct - anterolateral system

2. indirect - ascending reticular formation system (involved in consciousness)

Question 9

referred pain

Answer 9

visceral afferent and somatic afferent fibers enter the same posterior root
-visceral afferent fibers have collaterals that synapse on somatosensory afferent fibers causing referred pain

Question 10

sympathetic vs. parasympathetic levels

Answer 10

SNS - thoracolumbar (T1-L2/3)

PNS - craniosacral (S2-S4)

Question 11

CN 9 and 10**

Answer 11

contain sensory ganglion (collection of cell bodies)

• both carotid sinus and carotid body afferent fibers carried to CNS via CN9 (glossopharyngeal)
• aortic baroreceptors and chemoreceptors afferent fibers carried to CNS by CN10 (vagus)
• fibers merge together when entering CNS at solitary nucleus (medulla)

Question 12

what nerve is the info. from the carotid body and sinus carried by?

Answer 12

CN9 (glossopharyngeal)

Question 13

what nerve is the baroreceptor and chemoreceptor of aortic arch and body carried by?

Answer 13

CN10 (vagus)

Question 14

projections from solitary nucleus**

Answer 14

1. brainstem and hypothalamus
2. dorsal vagal nucleus - preganglionic parasympathetic fibers; vagal trigone associated –> thoracic and abdominal viscera
3. nucleus ambiguous - fibers to RALM (parasympathetic) –> larynx, pharynx, and esophagus muscles
4. rostral anterolateral medulla (RALM) –> intermediolateral cell column (sympathetic fibers)

Question 15

dorsal vagal nucleus and nucleus ambiguous

Answer 15

parasympathetic fibers that bring about a vasodepressor response (decrease HR, BP)
-decrease when dealing with orthostatic hypotension

Question 16

rostral anterolateral medulla

Answer 16

sympathetic fibers that bring about a vasopressor response (increase HR, BP)
-decrease when dealing with HTN, increase with orthostatic hypotension

Question 17

what occurs with lesion in thalamoperforating artery?

Answer 17

damage to ARAS in thalamus leading to coma

Question 18

what are the 4 sympathetic ganglion?

Answer 18

celiac, aorticorenal, superior, and inferior mesenteric

Question 19

what comprises a nerve plexus?

Answer 19

sympathetic ganglion and preganglionic parasympathetic nerve fibers

Question 20

grey vs. white rami communicantes

Answer 20

white and grey - found from T1-L2

grey - found above T1 or below L2

Question 21

superior cervical ganglion

Answer 21

largest paravertebral ganglion

-give rise to internal carotid and external carotid nerves

Question 22

Horner syndrome

Answer 22

damage of superior cervical ganglion

-miosis, ptosis, flushing, anhidrosis

Question 23

what is the ENS normally regulated by?

Answer 23

• PNS - enhancing

- SNS - inhibitory

Question 24

solitary nucleus

Answer 24

brainstem structure coordinating autonomic functions - many connections with CAN

• dorsal vagal nucleus and nucleus ambiguous –> parasympathetic
• intermediolateral cell column and RALM –> sympathetic