How do receptors in the thermoregulatory center respond to changes in blood temperature?

Sourav PanNovember 12, 2024

Answered

The thermoregulatory center in the brain, primarily located in the hypothalamus, plays a crucial role in monitoring and responding to changes in blood temperature. Here’s how receptors in this center function in temperature regulation:

1. Detection of Temperature Changes

• The hypothalamus contains central thermoreceptors that are sensitive to changes in core body temperature. These receptors detect variations in blood temperature and receive input from peripheral thermoreceptors located in the skin, which sense external temperatures. This dual system allows for comprehensive monitoring of both internal and external temperature changes.

2. Integration of Signals

• When peripheral or central thermoreceptors detect a change in temperature, they send signals to the preoptic area of the hypothalamus. This area integrates the information to determine whether the body temperature is above or below the normal range (approximately 37°C or 98.6°F) .

3. Responses to Increased Blood Temperature

• If the hypothalamus detects an increase in blood temperature, it initiates several physiological responses:
  • Vasodilation: Blood vessels near the skin surface dilate, increasing blood flow to the skin and facilitating heat loss through radiation and convection.
  • Sweating: The hypothalamus activates sweat glands, leading to increased sweating. The evaporation of sweat from the skin surface cools the body.
  • Decreased Metabolic Rate: Hormonal signals may reduce metabolic activity, further decreasing heat production .
  • Behavioral Adjustments: Individuals may seek cooler environments or reduce physical activity to help lower body temperature.

4. Responses to Decreased Blood Temperature

• Conversely, if blood temperature drops, the hypothalamus triggers mechanisms to conserve and generate heat:
  • Vasoconstriction: Blood vessels constrict, reducing blood flow to the skin and minimizing heat loss.
  • Shivering: The hypothalamus stimulates muscle contractions (shivering) to generate heat through increased metabolic activity.
  • Increased Metabolic Rate: Hormones may be released to enhance metabolic processes that produce more heat .
  • Behavioral Adjustments: Individuals may seek warmth by wearing more clothing or moving to warmer environments.