CID Autonomic Pharm

Question 1

Binding to muscarinic receptors cause what?

Answer 1

Contraction of smooth muscle

Question 2

What would a muscarinic receptor antagonist do?

Answer 2

Relax the target organ

Question 3

A man is walking and his HR and CO increase–> BP. What is responsible for this?

Answer 3

NE binding to B1 receptors -

B1 receptors are located on the AV nod.

Increase the rate and strength of contraction

Question 4

Alpha 1 receptors do what?

Answer 4

Increase BP by causing vasoconstriction, controlling the smooth muscle around the vasculature.

Question 5

Increase CO is proportional to an increase in what?

Answer 5

PRESSURE

Question 6

A1 agonists do what?

What is an example?

Answer 6

Increase mean BP

decrease HR

Ex. Phenylephrine

Question 7

A1 agonists (phenylephrine) increases BP, but decrease HR.

How does this affect sympathetics?

Answer 7

-Increase baroreceptor reflex

-increase parasympathetic response

- Decrease sympathetic response

Question 8

What does histamine do?

Answer 8

Decreases BP.

-Decreases baroreceptor firing

-Decrease parasympathetics

-Increase sympathetics

Question 9

NET and DAT inhibitors do what?

Give an example

Answer 9

Increase NE/DA in the cleft.

Ex. Cocaine

Question 10

What would a AChE inhibitor do?

Answer 10

Increase amount of ACh

-Cause ACh to bind to muscarinic receptors

-Decrease in HR

Question 11

VMAT inhibitors

Answer 11

Reduce the release of cathecholamines because it blocks them from entering the vesicles.

Question 12

Pt comes in with SOB, wheezing, tachycardia, RR or 32/min. How can we treat?

Answer 12

1. Beta 2 receptor agonist- relaxes smooth muscle in the lungs
2. mAChR antagonist- relaxes smooth muscle (give if the pt does not respond to muscarinic agonists)

Question 13

John is a given a drug that will increase the force of contraction (+ ionotropy) and decrease the HR (negative chronotropy) of cardiac contraction.

What is the target of the drug?

Answer 13

Na+/K+ ATPase blockers

(Cardiac glycosides)

Question 14

How do cardiac glycosides work?

Answer 14

Cardiac glycosides, like digoxin, will block Na+/K+ pumps, causing a buildup of Na+ inside the cell. To prevent a build up, we activate the NCX receptors, which allow 3 Na+ to leave and 1 Ca2+ to enter.

Thus, it causes an increase in intracellular Ca2+.

This will increase the force of contraction, but decrease our heart rate.

Question 15

B1 receptors

____ force of contraction

_____ heart rate

Answer 15

Increase the force of contraction (+ ionotropic effect)- more blood is delivered to the tissue

increase the heart rate (+ chronotropic effect)

Question 16

M2 and M3

___ force of contraction

____ heart rate

Answer 16

Decrease force of contraction (negative ionotropic effect)

Decrease heart rate (negative chronotropic effect)

Question 17

In heart failure; we see a decrease CO.

How does our body respond

Answer 17

1. Decrease firing of baroreceptors

• -decrease parasympathetic activity
• -increase sympathetic activity (increase force, increase HR, increase preload, increase afterload)

2. Decrease a renal blood flow will cause renin to be released.

• -angiotensinogen–> angiotensin 2
  
  • Adrenal medulla- release of aldosterone
  • Posterior pituitary- release of ADH (vasopressin
  • Hypothalamus- increase thirst
  • Vasoconstriction
• Increases preload, afterload and remodlings
• This can cause EDEMA

Question 18

How can we decrease the force and rate of cardiac contraction?

Answer 18

1. Muscarinic agonist
2. B1 receptor antagonist

Question 19

2 yo old had an accidental overdose on antihistamines.

high temp

pupils are fixed and dilated

HR is 160 bpm

Cutaneous vasodilation

What receptors are involved?

Answer 19

Muscarinic receptor antagonist =

Decreases parasympathetic tone

increases sympathetic

-Patient cannot sweat anymore and gets hot, causing an increase in temperature. To cool off, the bodies compensatory response is to vasodilate.

Question 20

2 yo old had an accidental overdose on antihistamines.

high temp

pupils are fixed and dilated

HR is 160 bpm

Cutaneous vasodilation

What receptors can we stimilate to corrext sx? W what type of drug?

Answer 20

-mAChR via a AChE inhibitor