When a person becomes "pale," what is the physiologic basis?
A) The blood supply to the skin increases.
B) The number of red melanocytes in the skin increases.
C) Melanocytes increase production of red pigments.
D) The blood supply to the skin decreases.
E) Increased heat causes the skin to turn red.
D) The blood supply to the skin decreases.
You might also like to view...
One "strong" stimulus can cause more than one action potential, but a "weak" stimulus may or may not generate an action potential
Indicate whether the statement is true or false
A sphincter is a
A. thickening of the longitudinal layer of the muscularis that propels materials through the GI tract. B. circle of adventitia that anchors the GI tract to neighboring structures. C. thickening of the circular layer of the muscularis that controls movement of materials through the GI tract. D. fold of the mucosa of the GI tract that increases the total surface area for absorption of nutrients.
What Arctic animals use countercurrent circulation? Where in those animals is it most conspicuous?
What will be an ideal response?
Occlusion of blood vessels tends to lead to
A. increases in perfusion. B. defibrillation of cardiac muscle cell contraction. C. increases in capillary exchange. D. inadequate blood supply and damage to body tissues.