Practice Test 12

A neonatal intensive care unit study compared hormone responses to a brief heel-stick procedure (painful stimulus). Preterm infants received either sucrose solution orally (analgesic) or water before the procedure. Plasma cortisol was measured 20 minutes later; cortisol was lower in the sucrose group.

Which interpretation is most consistent with the integration of nervous and endocrine signaling in this setting?

Investigators examined the effect of a brainstem vagal stimulation protocol on postprandial insulin secretion in humans. Participants consumed a standardized mixed meal; half received transcutaneous vagal stimulation (tVNS) for 10 minutes starting at meal onset. Plasma insulin and glucose were measured.

Which of the following best explains the relationship between the neural stimulus and the hormonal response?