Human Digestive System and Nutrition Flashcards

Vocabulary-style flashcards covering the human digestive system, nutrition processes, enzymes, and the differences between egestion and excretion.

Ingestion

The process of taking in food through the mouth.

Digestion

The breaking down of large complex insoluble food molecules into small simple soluble food molecules.

Absorption

The passing of soluble food molecules into body fluids and body cells.

Assimilation

The use of soluble food molecules by body cells.

Egestion

The removal of undigested food molecules from the body through the anus.

Mastication

Mechanical digestion of food using the teeth and tongue in the mouth.

Bolus

A ball of food formed by the tongue that can be swallowed.

Peristalsis

A process where muscles contract behind food and relax in front of it to push food and liquid through the GI tract.

Salivary amylase

An enzyme in saliva that begins the chemical digestion of starch.

Gastric juice

A substance secreted by the stomach wall containing mucus, hydrochloric acid ($HCl$), and pepsin.

Pepsin

A protease enzyme in the stomach that begins the digestion of protein.

Chyme

The creamy mixture of food and gastric juices that is emptied from the stomach into the small intestine.

Bile

A substance made in the liver and stored in the gallbladder that contains bile salts to emulsify fats.

Sodium hydrogen carbonate

A substance secreted by the liver and pancreas to neutralise stomach acid.

Pancreatic juice

A secretion from the pancreas containing the enzymes amylase, trypsin, and lipase.

Carbohydrases

A category of enzymes that break down carbohydrates into simple sugars like glucose.

Proteases

A category of enzymes, such as pepsin and trypsin, that break down proteins into amino acids.

Lipases

A category of enzymes that break down lipids (fats and oils) into fatty acids and glycerol.

Duodenum

The first part of the small intestine where chyme is mixed with bile and pancreatic juice.

Ileum

The part of the small intestine where absorption of minerals, vitamins, glucose, amino acids, fatty acids, and glycerol occurs.

Large intestine

The organ that absorbs water, ions, and vitamins, turning waste into stool.

Rectum

The lower end of the large intestine where stool is stored before egestion.

Excretion

The discharge of metabolic wastes such as sweat, urine, and carbon dioxide from the cells of the body.

Trypsin

A protease enzyme produced in the pancreas and used in the small intestine.

Maltase

An enzyme produced in the wall of the small intestine that completes the digestion of starch.