Which receptor type monitors chemical contents in the digestive system?

• A. Baroreceptors
• B. Chemoreceptors
• C. Mechanoreceptors
• D. Photoreceptors

Answer: (B)

Chemoreceptors are the receptors that monitor chemical contents in the digestive system. They sit in the mucosa of the stomach and intestines and detect changes in the chemical makeup of chyme, such as acidity (pH), osmolarity, and the presence of nutrients or ions. When these chemical cues are detected, chemoreceptors trigger reflexes that adjust digestion—stimulating or inhibiting acid and enzyme secretion, influencing gut motility, and signaling the release of hormones like secretin and cholecystokinin to coordinate digestive processes. This specialization distinguishes them from baroreceptors, which detect pressure changes in blood vessels; mechanoreceptors, which sense physical stretch; and photoreceptors, which respond to light.