Question

1. explain the role that blood vessels play in regulating body temperature. (use vocabulary - vasodilation and vasoconstriction. 2

Explanation:

To regulate body temperature, blood vessels use vasodilation and vasoconstriction. When the body is too warm, vasodilation occurs: blood vessels near the skin’s surface widen (dilate), allowing more blood to flow near the skin. This increases heat loss (e.g., via radiation, convection) to cool the body. When the body is too cold, vasoconstriction occurs: blood vessels near the skin’s surface narrow (constrict), reducing blood flow to the skin. This minimizes heat loss, helping retain warmth. These processes are part of the body’s thermoregulatory mechanisms.

Answer:

• Vasodilation: When the body is overheated, blood vessels (arterioles/capillaries near the skin) dilate. This increases blood flow to the skin’s surface, promoting heat loss (e.g., through radiation, convection) to cool the body.
• Vasoconstriction: When the body is cold, blood vessels near the skin constrict. This reduces blood flow to the skin, minimizing heat loss and helping retain body warmth.