When the sympathetic nervous system is activated: (A) Norepinephrine is released by the vascular smooth muscle cells, (B) Acetylcholine is released onto vascular smooth muscle cells, (C) Norepinephrine is released from axons onto the aeriolar wall, (D) The aerioles constrict because nitric oxide production is suppressed
Answer is C. Nerve fibers, not vascular smooth muscle, release norepinephrine. The norepinephrine from the sympathetic nerves simply diffuses from the axons and binds to specific receptors on smooth muscle cells.