blood flow in skin?

Question

how come it says that the skin may stay rosy when the temperature is low because chilled skin cells take up less oxygen? what has oxygen to do with it? thanks.

Answer 1

Alright, with a low temperature the blood vessels constrict (vasoconstriction) for the purpose of reducing heat loss by reducing the blood flow to the skin while keeping the heat centralized in the body's core. That means the skin cells would take less oxygen as there is decreased blood flow. As the result, the skin will get the warm core blood away from areas that have large temperature gradient. The skin in return will cool and the temperature gradient between the skin and the environment will also become smaller.

As vasoconstriction takes happens, "Vasodilation" can also occur as a response to greatly reduced skin temperatures that could potentially lead to cold injury. When skin temperatures fall too low (below 50 degrees Fahrenheit), limb vessels will enlarge briefly a few times a minute in an attempt to raise skin temperature without sacrificing core temperature. That is the reason why you can have rosy cheeks on a chilly day, even though the skin surface typically vasoconstricts in the cold.

Answer 2

When you are cold, your brain sends more blood to the center of your body to keep your internal organs at their normal temp of 98 degrees or so. Because the blood is moved from outer to inner when it's cold, the chilled skin cells require less oxygen, which makes up for the reason of the blood being sent to the center of the body (well, not all of it obviously) If chilled skin cells required more oxygen, then when you are cold and blood is sent toward the center, there would be harm to skin cells after long periods of time. Remember, when cells are cold, metabolic processes slow down, therefore requiring less oxygen.
Keep in mind that the two areas in the body where there are no blood vessels, however, are the epiderms and the cornea.