Which of the following serves as a sensor, or as part of a sensor, that functions in a negative feedback system?

A. Mechanically-gated channels located in the plasma membranes of the peripheral axon terminals of carotid artery baroreceptor neurons.

B. Osmoreceptor neurons whose peripheral terminals are located in the walls of the carotid artery.

C. Calcium-Sensing Receptors (CaSRs) located in the plasma membranes of Parathyroid Gland cells.

D. A and B.
E. A and C.
F. B and C.
G. A, B, and C.
H. None of the above.

2. Which of the following serves as an actuating signal, or as part of an actuating signal, in
a negative feedback system?
A. Blood plasma levels of oxytocin.
B. Blood plasma levels of glucagon.
C. Blood plasma levels of Vasopressin Releasing Hormone (VRH).
D. A and B.
E. A and C.
F. B and C.
G. A, B, and C.
H. None of the above.

3. Which of the following serves as an effector, or as part of an effector, in a negative feedback system?
A. GLUT2 molecules in the plasma membranes of liver cells.
B. Binding sites for calcium ions on tropomyosin molecules in rib cage inspiratory muscles.
C. Glycogen Receptors in the plasma membranes of liver cells.
D. A and B.
E. A and C.
F. B and C.
G. A, B, and C.
H. None of the ab