Neurotransmitters of the Autonomic Nervous System
Parasympathetic postganglionic axons secrete acetylcholine into synapses. Acetylcholine is rapidly decomposed by an enzyme in synapses. Most sympathetic postganglionic axons secrete norepinephrine (noradrenaline) into synapses. Most of the norepinephrine released by neurons is reabsorbed into nerve endings by active transport. Norepinephrine reabsorption may take a few seconds during which time some molecules may enter the blood and remain active until they diffuse into tissues containing decomposing enzymes.
Based on this information, which prediction can be made about the different actions of the two regulatory mechanisms?
A.Acetylcholine produces a more prolonged effect than norepinephrine.
B.Norepinephrine produces a more prolonged effect than acetylcholine.
C.Parasympathetic fibres transmit impulses faster than sympathetic fibres.
D.More energy is required to reabsorb acetylcholine molecules than to reabsorb norepinephrine.
2007-02-26 04:31:50 · 4 answers · asked by Anonymous in Science & Mathematics ➔ Biology
I would also go for B!
2007-02-26 06:18:55 · answer #1 · answered by Lilly26 3 · 1⤊ 0⤋
sounds like B to me
2007-02-26 12:38:04 · answer #2 · answered by JulzyA 2 · 0⤊ 0⤋
B.
2007-02-26 12:36:47 · answer #3 · answered by Brian L 7 · 0⤊ 0⤋
C !!!
2007-02-26 12:43:33 · answer #4 · answered by Anonymous · 0⤊ 0⤋