Question

Predict the effect of each of the following conditions on blood

flow: a) vasoconstriction of blood vessels in the skin in response
to cold exposure; b) vasodilation of the blood vessels in the skin
in response to an elevated body temperature; c) polycythemia vera,
which results in a greatly increased RBC count.

Answer 1

Vasoconstriction - increase blood flow; vasodilatation and polycythemia - decrease blood flow.

Step-by-step explanation:

When the body is in cold exposure, it causes blood vessel contraction, or vasoconstriction, a nervous system-mediated response to regulate the bodys temperature. The blood flow increases.

Vasodilation is the process of dilating blood vessels by relaxing the smooth muscles of the vessels and is related to the maintenance and regulation of body temperature. This happens in response to elevated body temperature. The blood flow descrease, to not increase the body temperature. Exposure to heat causes vasodilation. Vasodilation causes decreased blood pressure and heat loss to the outside.

Polycythemia vera, like myelofibrosis, is a type of blood cancer that belongs to the group of myeloproliferative diseases. It is due to a mutation in the marrow cells, which mainly affects the production of red blood cells (erythrocytes). Increased production of red blood cells causes thickening of the blood, which can cause changes in its flow (decrease blood flow) and circulatory problems.