Question

α (alpha) adrenoceptors

A. Are located on myofilaments in smooth muscle cells.

B. Are distinguishable from (beta) receptors using electron microscopy.

C. Can be stimulated by both adrenaline and noradrenaline.

D. Are involved in the vasoconstrictor responses in skin to adrenaline.

E. Are involved in the heart rate responses to noradrenaline.

Answer 1

A. False They are located in the cell membranes.

B. False They cannot be visualized; chemical evidence suggests their structure is similar.

C. True Also by drugs such as ephedrine which has a similar structure.

D. True Alpha receptors predominate in skin arterioles.

E. False Cardiac adrenoceptors are predominantly beta receptors.