Which zone responds to a decrease in temperature?

Which zone responds to a decrease in temperature?

• A. Posterior zone
• B. Anterior zone
• C. Suprachiasmatic nucleus
• D. Lateral hypothalamus

Answer: (A)

When temperature falls, the body uses the hypothalamus to mount a cold-defense response. The posterior region acts as the cold-defense center, activating mechanisms to generate and conserve heat. It triggers shivering and metabolic increases, and causes vasoconstriction to reduce heat loss (along with other responses like piloerection in some animals). By contrast, the anterior region senses heat and promotes cooling behaviors (like vasodilation and sweating). The suprachiasmatic nucleus governs circadian rhythms, not immediate temperature responses, and the lateral hypothalamus is more involved in hunger and arousal. So the zone that responds to a decrease in temperature is the posterior zone.

When temperature falls, the body uses the hypothalamus to mount a cold-defense response. The posterior region acts as the cold-defense center, activating mechanisms to generate and conserve heat. It triggers shivering and metabolic increases, and causes vasoconstriction to reduce heat loss (along with other responses like piloerection in some animals).

By contrast, the anterior region senses heat and promotes cooling behaviors (like vasodilation and sweating). The suprachiasmatic nucleus governs circadian rhythms, not immediate temperature responses, and the lateral hypothalamus is more involved in hunger and arousal. So the zone that responds to a decrease in temperature is the posterior zone.