Lecture 4 - ANS 2 - Sympathetic Agonists and Antagonists Flashcards
1
Q
Describe the selectivity of adrenoceptors
A
Are relatively unselective for the two neurotransmitters - adrenaline (A) and noradrenaline (NA)
Both NA and A activate alpha and beta adrenoceptors
2
Q
What is the function of alpha 1 agonists?
A
Constrict most smooth muscle except in the GI tract where they relax
3
Q
What is the function of alpha 2 agonists?
A
Mediate presynaptic inhibition of neurotransmitter release - sympathetic and parasympathetic neurons
4
Q
What is the function of beta1 agonists?
A
Increase HR and force the contraction
5
Q
What is the function of beta2 agonists?
A
Dilate/relax smooth muscle
6
Q
What is the function of beta3 agonists?
A
Stimulate thermogenesis in skeletal muscles
