Which brain region serves as the primary hypothalamic regulator of body temperature in adults?

Which brain region serves as the primary hypothalamic regulator of body temperature in adults?

• A. The posterior hypothalamus.
• B. The suprachiasmatic nucleus.
• C. The preoptic area of the anterior hypothalamus.
• D. The dorsomedial nucleus.

Answer: (C)

The preoptic area of the anterior hypothalamus acts as the primary regulator of body temperature because it contains warm-sensitive neurons that monitor core temperature and compare it to the body's set point. When the core temperature rises, these neurons trigger heat-dissipating responses such as cutaneous vasodilation and sweating, helping to lower temperature. When the temperature falls, the same region reduces heat-loss signals and helps mobilize heat-producing and conserving mechanisms, coordinating with other hypothalamic areas to generate warmth. The posterior hypothalamus participates mainly in heat production and conservation when cooling is needed, rather than serving as the central thermostat. The suprachiasmatic nucleus governs circadian rhythms, including daily temperature cycles, but it is not the primary regulator of acute thermoregulation. The dorsomedial nucleus has autonomic and metabolic roles but is not the principal temperature control center.

The preoptic area of the anterior hypothalamus acts as the primary regulator of body temperature because it contains warm-sensitive neurons that monitor core temperature and compare it to the body's set point. When the core temperature rises, these neurons trigger heat-dissipating responses such as cutaneous vasodilation and sweating, helping to lower temperature. When the temperature falls, the same region reduces heat-loss signals and helps mobilize heat-producing and conserving mechanisms, coordinating with other hypothalamic areas to generate warmth.

The posterior hypothalamus participates mainly in heat production and conservation when cooling is needed, rather than serving as the central thermostat. The suprachiasmatic nucleus governs circadian rhythms, including daily temperature cycles, but it is not the primary regulator of acute thermoregulation. The dorsomedial nucleus has autonomic and metabolic roles but is not the principal temperature control center.