Predict the effect of each of the following conditions on blood pressure:
(a) vasoconstriction of blood vessels in the skin in response to cold exposure.
vasoconstriction will lead to increased overall blood pressure, keeping blood towards the more deep structures, retaining warmth.
(b) vasodilation of the blood vessels in the skin in response to an elevated body temperature.
vasodilation will lead to decreased overall blood pressure. The warm blood will be close to the surface, so evaporative cooling can take place.
(c) erythrocytosis, which results in a greatly increased hematocrit.
erythrocytosis will lead to blood that is more viscous, leading to a higher resistance, which will increase blood pressure.