BIOL 200 Lecture Notes - Aorta, Cardiac Muscle, Sinoatrial Node
19 Jan 2013
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Document Summary
Acetylcholine released by: motor neurones on to muscle cells, neurones in the parasympathetic division of the ans (autonomic nervous system) Noradrenaline is released in the sympathetic division of the ans. //the international name for noradrenaline is now norepinephrine. The agonistic and antagonistic effects of chemicals on. Agonists/antagonists are similar in shape to neurotransmitter: fit into specific protein receptors of postsynaptic membrane. Agonists same effect as neurotransmitter: anatoxin produced by some algae and mimics effect of acetylcholine, swallowing h2o contaminated with anatoxin causes continuous salvation in mouth. Antagonists block action of neurotransmitter: prevent neurotransmitter from binding with their receptor sites, high blood pressure can be treated by drugs called -blockers. Antagonist of adrenaline-receptors on membrane of muscle cells in heart: curare blocks action of acetylcholine at the junction of nerves and muscles. Useful as a general muscle relaxant in patients undergoing major surgery. Stimuli: change in internal or external environment.
