Neuro

Question 1

nucleus of the medulla that contains the preganglionic neurons of the parasympathetic, innervating esophagus, heart and respiratory systems

Answer 1

nucleus ambiguus

Question 2

CN X projects to

Answer 2

parasympathetic ganglia of heart, lungs, liver, gall bladder, pancreas, stomach, small intestine and rostral segments of GI tract

Question 3

Where is the sympathetic preganglionic cell column

Answer 3

in the intermediolateral cell column from T1 to L3

Question 4

What parasympathetic ganglion innervates the heart and lungs

Answer 4

stellate ganglion

Question 5

Why is referred pain felt with myocardial injury?

Answer 5

nociceptive efferents from the viscera and areas of the skin converge on the same projection neurons in the dorsal horn. The brain cannot tell what the source of the original signal was.

Question 6

Which cardiac nerve has more effect on HR?

Answer 6

right cardiac nerve (postganglionic fibers release NE)

Question 7

Which cardiac nerve has more effect on contractility?

Answer 7

left cardiac nerve

Question 8

Which nucleus does afferent fibers of baroreceptors project to?

Answer 8

NTS

release glutamate which binds to AMPA and GluR2

Question 9

part of the vasomotor area of the ventrolateral medulla that evokes a vasoconstrictor response when stimulated

Answer 9

C1
the NTS neurons inhibit this when blood pressure is elevated
it is responsible for the vascular response of the baroreceptor reflex
Note: clonidine binds to imidazole receptors on C1 neurons

Question 10

which nuclei are responsible for the bradycardia aspect of the baroreceptor reflex?

Answer 10

nucleus ambiguus and dorsal motor nucleus of the vagus

Question 11

which vagus nerve is a more effective inhibitor of conduction through the AV node

Answer 11

left vagus

Question 12

which vagus nerve inhibits HR?

Answer 12

right vagus

Question 13

Where are the cell bodies of the CN IX?

Answer 13

petrosal ganglion

Question 14

Where are the cell bodies of the aortic baroreceptor?

Answer 14

nodose ganglion

Question 15

Which fibers of the atrial low pressure sensors monitor atrial filling?

Answer 15

B fibers

these monitor venous return

Question 16

Which nucleus synthesizes vasopressin and releases it in response to atrial low-pressure sensor firing?

Answer 16

PVN of the hypothalamus

Question 17

How does a beta-1 agonist exert an inotropic effects on the myocardial cells?

Answer 17

through protein kinase A

alpha-s subunit directly activates L-type calcium channels

Question 18

how does M3 activation lead to vasodilation?

Answer 18

increases intracellular calcium which then stimulates NO synthase. NO synthase indirectly inhibits calcium influx through L-type channels

Question 19

Why do coronary bvs dilate in response to epinephrine?

Answer 19

coronary bvs have more beta-2 receptors than alpha-1, so vasodilation is the dominant response

Question 20

Why is epinephrine not a systemic vasodilator?

Answer 20

beta-2 receptors are concentrated in skeletal muscle, liver, heart and adrenal medulla

Question 21

how does bradykinin promote vasodilation?

Answer 21

binds to beta-2 receptor on endothelial cells and causes release of NO and prostaglandins

Question 22

Which part of the hypothalamus mediates decrease in body temp?

Answer 22

anterior

panting, vasodilation, suppression of shivering

Question 23

which part of the hypothalamus mediates increase in body temp?

Answer 23

posterior

shivering

Question 24

Loss of consciousness in response to emotional stress: Bezold Jarisch reflex
vasovagal response

Answer 24

vagal afferents carry signal to higher CNS centers and result is massive PNS stimulation abolishing sympathetic tone
This causes massive vasodilation and the drop in blood pressure does not elicit the baroreceptor response.
Decreased MAP causes global cerebral ischemia. Hyperventilation decreases PCO2 and further decreases cerebral flow by causing vasoconstriction.
End result: bradycardia and decreased CO from intense vagal output

Question 25

Phases of valsalva response

Answer 25

Phase I: increased BP causes decreased HR
Phase II: decreased venous return decreases MAP -> reflex tachycardia & peripheral vasoconstriction
(release)
Phase III: decreased intrathoracic pressures decreases BP and increases HR
Phase IV: rapid venous return increases BP & get overshoot of BP with reflexive bradycardia after 5-6 seconds