REVIEW

Question 1

Describe the mechanism for adrenergic alpha-1 receptors.

Answer 1

Vasoconstriction. Increases intracellular calcium and induces contraction

Question 2

Describe the mechanism for adrenergic alpha-2 receptors.

Answer 2

Act at the presynaptic termini by inhibiting neurotransmitter release (epi and norepi) so it causes relaxation or vasodilation. It decreases calcium levels in the presynaptic terminus- calcium is essential for neurotransmitter release.

Question 3

Describe the mechanism for adrenergic beta-1 receptors.

Answer 3

Found on the heart- increase contractility/cardiac output.

Question 4

Describe the mechanism for adrenergic beta-2 receptors.

Answer 4

Found on smooth muscle cells (bronchodilators)- decreases intracellular calcium and causes relaxation of muscles

Question 5

Describe the mechanism for nicotinic receptors.

Answer 5

Ligand activated ion channel (Na+).

Question 6

Describe the mechanism for muscarinic receptors.

Answer 6

These are all G coupled protein receptors. M1, M3, M5- all are excitatory increase intracellular calcium levels. However, their action is location dependent. M3- ciliary contraction decreases intraocular pressure, stimulates salivation, induces vasodilation, detrusor muscle contraction (voids bladder), bronchoconstriction.
M2 and M4 are inhibitory- they inhibit adenylate cyclase- this causes muscle relaxation and such

Question 7

Describe the mechanism for how local anesthetics work.

Answer 7

Inject, (not intravenously) the basic form of the drug gets through the membrane. Then the acidic form blocks the sodium channel thereby cutting off pain signals to the CNS.