A term neonate is delivered and placed under a radiant warmer. Unlike adults, neonates cannot effectively generate heat through shivering. The primary mechanism of heat production in neonates is:

• A Metabolism of brown adipose tissue ✓
• B Increased skeletal muscle activity
• C Vasoconstriction of peripheral vessels
• D Metabolism of white adipose tissue

Explanation

Neonates rely on non-shivering thermogenesis, primarily through metabolism of brown adipose tissue. Brown fat is rich in mitochondria containing uncoupling protein 1, also called thermogenin, which dissipates the proton gradient to generate heat rather than ATP. Brown fat is deposited around the neck, mediastinum, and interscapular region during the third trimester. Shivering thermogenesis is functionally immature in neonates, making brown fat their principal heat source.

Reference: Guyton and Hall Textbook of Medical Physiology, 14th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.