L11: Drugs affecting SNS 2

Question 1

Describe the effects of the activation of alpha & beta receptors

Answer 1

alpha: muscle contraction & vasoconstriction

beta: muscle relaxation & vasodilation

Question 2

What does noradrenaline & adrenaline activate to produce their effects?

Answer 2

“Adrenoreceptors”

Question 3

Define adrenoceptors

Answer 3

Group of nine 7-transmembrane receptors made of a1, a2 & a3

Question 4

Main responses for a1 receptor

Answer 4

• Smooth muscle contraction, vasoconstriction

Question 5

Main responses for a2 receptor

Answer 5

Presynaptic inhibition of noradrenaline release

Question 6

Main responses for b1 receptor

Answer 6

Increase heart rate & force of contraction of cardiac muscle

Question 7

Main responses of b2 receptor

Answer 7

Smooth muscle relaxation, vasodilation

Question 8

How does the SNS maintain our blood pressure?

Answer 8

1. Blood pressure falls
2. Decrease activation of arterial baroreceptors
3. Decrease stimulation of CV centre in medulla
4. Increase CO
5. Vasoconstriction so increase in TPR

Question 9

What is blood pressure proportional to?

Answer 9

Cardiac Output x Total Peripheral Resistance (TPR)

Question 10

Role of baroreceptors

Answer 10

Monitor how much blood is in our blood vessels & our blood pressure

Question 11

Define agonists

Answer 11

Drug or substance that binds to receptor