Sympathetic nervous system

Question 1

Adrenoceptors (G-Protein Family)

Answer 1

Agonists (sympathomimetrics)
Antagonists

Question 2

Role of ß1 adrenoceptors in the heart:

Answer 2

Increased contractility

Question 3

Sympathetic control of pupil diameter

Answer 3

Radial muscle = smooth muscle arranged radially.

Sympathetic nerve action = radial muscle contraction —> pupil dilation (mydriasis)

Circular muscle = smooth muscle arranged concentrically, regulated by parasympathetic nervous system.

Question 4

Hormones in sympathetic control of pupil diameter

Answer 4

Noradrenaline —> Alpha adrenoceptors on radial muscle Loss —> radial muscle contraction—> mydriasis (pupil dilation)