REVIEW Flashcards
Describe the mechanism for adrenergic alpha-1 receptors.
Vasoconstriction. Increases intracellular calcium and induces contraction
Describe the mechanism for adrenergic alpha-2 receptors.
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.
Describe the mechanism for adrenergic beta-1 receptors.
Found on the heart- increase contractility/cardiac output.
Describe the mechanism for adrenergic beta-2 receptors.
Found on smooth muscle cells (bronchodilators)- decreases intracellular calcium and causes relaxation of muscles
Describe the mechanism for nicotinic receptors.
Ligand activated ion channel (Na+).
Describe the mechanism for muscarinic receptors.
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
Describe the mechanism for how local anesthetics work.
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.