In a negative feedback loop governing body temperature, which components are correctly identified? Receptors, control center, and effectors.

• A. Receptors in skin/thermoreceptors detect temperature; the hypothalamus acts as the control center; effectors (sweat glands, blood vessels, skeletal muscles) adjust heat loss or production.
• B. Receptors detect temperature; brainstem is the control center; effectors modify hormones to adjust metabolism.
• C. Receptors in muscles detect temperature; the hypothalamus is the control center; effectors are only endocrine glands.
• D. Receptors in skin detect temperature; the control center is the adrenal gland; effectors are sweat glands.

Answer: (A)

Maintaining body temperature uses a negative feedback loop where sensors detect a change, the brain processes it, and effectors act to oppose the change. Receptors in the skin and central thermoreceptors in the hypothalamus monitor temperature. The hypothalamus serves as the control center, integrating this information and coordinating responses. The effectors—sweat glands, blood vessels in the skin, and skeletal muscles—adjust heat loss or heat production to bring temperature back toward the set point. When hot, sweating and vasodilation increase heat loss; when cold, vasoconstriction and shivering increase heat production and retention. The other options place the control center in the brainstem or adrenal gland, misidentify where receptors are located, or restrict effectors to endocrine glands, which doesn’t fit the rapid autonomic regulation of temperature.