Where is brown adipose tissue (BAT) located in newborns?

• A. Between the liver and spleen.
• B. Between the scapulae, around the neck, in the axillae, and behind the sternum.
• C. In the bones of the limbs.
• D. In the floor of the mouth.

Answer: (B)

Brown adipose tissue in newborns is there to generate heat through non-shivering thermogenesis. It’s found in several depots in the upper body: between the scapulae, around the neck, in the axillae, and behind the sternum. These locations place BAT near key blood vessels, allowing rapid heat production to help the newborn regulate temperature after birth. The other sites listed aren’t typical BAT locations (for example, bones or floor of the mouth aren’t BAT depots), while BAT diminishes with age and becomes limited to small areas in adulthood.