Human Digestive System and Salivary Action Flashcards

Vocabulary flashcards based on the lecture notes covering human digestion, salivary activity, and gastric secretions.

Saliva

A fluid secreted by the salivary glands that wets food to make its passage smooth and contains enzymes.

Biological catalysts

Also known as enzymes, these substances help break down complex food into smaller molecules for absorption.

Salivary amylase

An enzyme present in saliva that breaks down starch, a complex molecule, to give simple sugar.

Peristaltic movements

Rhythmic contractions of the muscles in the lining of the digestive canal that push food forward along the gut.

Oesophagus

The food-pipe through which food is taken from the mouth to the stomach.

Stomach

A large organ that expands when food enters it and uses its muscular walls to mix food with digestive juices.

Gastric glands

Glands present in the wall of the stomach that release hydrochloric acid, pepsin, and mucus.

Pepsin

A protein-digesting enzyme released by the gastric glands.

Hydrochloric acid

A substance that creates an acidic medium to facilitate the action of the enzyme pepsin.

Mucus

A secretion that protects the inner lining of the stomach from the action of hydrochloric acid under normal conditions.

Iodine solution

A dilute substance used in Activity 5.3 to test for the presence of starch via a color change.

Starch solution

A complex carbohydrate solution used in Activity 5.3 at a concentration of $1\%$.

Muscular tongue

An organ used to thoroughly mix food with saliva and move it around the mouth while chewing.