Question

1. Name one receptor found on a target tissue in the sympathetic division of the ANS. What neurotransmitter acts at this receptor?

2. Mr. Martin’s heart rate is too high. The physician performs a maneuver that stimulates vagus to slow his heart rate.
  What neurotransmitter is being released, and what receptors are being stimulated to slow Mr. Martin’s heart rate?

Answer 1

1. Sympathetic stimulation causes vasoconstriction of most blood vessels ( in skin , digestive system etc. ).

Target tissue - blood vessels.

Here , the receptor is alpha -1 adrenergic receptor.

The neurotransmitter is norepinephrine.

2. The physician here has performed a vagal maneuver. Vagal maneuvers are technics used to increase the vagal parasympathetic tone. The common vagal maneuvers are carotid sinus massage and valsalva maneuver. The end product of vagal stimulation is a decrease in speed and frequency of electrical signals in the heart.

Here , the neurotransmitter is acetylcholine.

The receptor stimulated is M2 receptor (muscaranic receptor)