Pharynx, Esophagus & Stomach

What is a bolus?

A ball of chewed food.

What is the epiglottis?

A flap that closes the trachea during swallowing.

What is peristalsis?

Involuntary wave‑like muscle contractions moving food.

What is the cardiac sphincter?

Prevents food from re‑entering the esophagus.

What is chyme?

Mixture of food, mucus, and acid.

What does the pyloric sphincter do?

Releases small amounts of chyme into the small intestine.

What do mucous cells do?

Protect stomach lining.

What do parietal cells produce?

Hydrochloric acid (HCl).

What do chief cells produce?

Pepsinogen → becomes pepsin.

What does pepsin do?

Digests proteins.

What do enteroendocrine cells release?

Serotonin, histamine, somatostatin.

What do G‑cells secrete?

Gastrin.