The postganglionic sympathetic neurotransmitter is a biogenic amine.

The postganglionic sympathetic neurotransmitter is a biogenic amine.

• A. Biogenic amines
• B. Acetylcholine
• C. Neurotensin
• D. Peptides

Answer: (A)

The main idea is the chemical nature of the primary transmitter released by sympathetic postganglionic neurons. In most cases, this transmitter is norepinephrine, a biogenic amine derived from tyrosine. That makes the postganglionic sympathetic transmitter a biogenic amine, which is why this option is correct. Remember that norepinephrine acts on adrenergic receptors at target organs. An important exception is sweat glands, where the sympathetic system uses acetylcholine as the transmitter, so not all sympathetic postganglionic signaling fits the general pattern. Neurotensin and peptides are not the typical transmitters for this pathway.

The main idea is the chemical nature of the primary transmitter released by sympathetic postganglionic neurons. In most cases, this transmitter is norepinephrine, a biogenic amine derived from tyrosine. That makes the postganglionic sympathetic transmitter a biogenic amine, which is why this option is correct. Remember that norepinephrine acts on adrenergic receptors at target organs. An important exception is sweat glands, where the sympathetic system uses acetylcholine as the transmitter, so not all sympathetic postganglionic signaling fits the general pattern. Neurotensin and peptides are not the typical transmitters for this pathway.