Human Digestive System and Digestion Processes

This set of vocabulary flashcards covers the organs, functions, stages of digestion, and specific chemical and mechanical processes of the human digestive system as outlined in the lecture notes.

Digestive System

A system that breaks down foods into smaller pieces and absorbs the nutrients from the food you eat.

Gastrointestinal tract (GI tract)

The pathway of the digestive system that extends from the mouth to the anus.

Bolus

A moistened ball of food created by the salivary glands to facilitate swallowing.

Salivary Glands

Glands that moisten food into a bolus and begin polysaccharide digestion.

Liver

An organ that detoxifies certain molecules, stores vitamins, iron, and glycogen, and synthesises bile.

Oesophagus

An organ that transports food to the stomach through peristalsis.

Stomach

An organ that stores and churns food, while beginning protein digestion using acids and proteases.

Gall Bladder

An organ that stores and concentrates bile produced by the liver.

Pancreas

An organ that releases digestive enzymes, bicarbonate ions to neutralise stomach acid, and hormones such as insulin.

Small Intestine

The primary site for nutrient absorption, utilizing peristalsis and membrane-bound enzymes.

Large Intestine

An organ responsible for absorbing water and ions, and moving waste via peristalsis.

Rectum / Anus

The final part of the digestive tract where faeces are stored and expelled.

Ingestion

The first stage of digestion involving taking food into the body.

Digestion

The second stage of digestion involving the breaking down of food.

Absorption

The third stage of digestion involving moving food into cells.

Assimilation

The fourth stage of digestion involving making food part of the cell.

Elimination

The final stage of digestion involving the removal of unused food or undigested material.

Mechanical Digestion

The physical breakdown of food through processes such as chewing, churning, peristalsis, and segmentation.

Chemical Digestion

The breakdown of food using chemicals such as stomach acid, bile, and enzymes via enzymatic hydrolysis.

Peristalsis

A type of mechanical digestion involving the movement of food in the esophagus, stomach, and intestines via muscle contraction.

Segmentation

Mechanical digestion in the intestines involving the contraction and relaxation of smooth muscles to mix food with digestive juices.

Churning

A mechanical digestion process where the stomach muscles mix food with digestive juices.

Salivary amylase

An enzyme in the mouth that converts $\text{starch} \rightarrow \text{maltose}$.

Proteases

Enzymes in the stomach that convert $\text{protein} \rightarrow \text{polypeptides}$.

Bile salts

Substances produced by the liver and stored in the gall bladder for the emulsification of lipids.

Pancreatic Amylase

An enzyme from the pancreas that breaks down $\text{starch} \rightarrow \text{maltose}$.

Lipase

An enzyme from the pancreas that converts $\text{triglycerides} \rightarrow \text{fatty acids}$.

Endopeptidase

An enzyme from the pancreas that converts $\text{peptides} \rightarrow \text{amino acids}$.

Nuclease

An enzyme from the pancreas that breaks down $\text{DNA/RNA} \rightarrow \text{nucleosides}$.

Bicarbonate ions

Ions released by the pancreas to neutralise stomach acid.

Maltase

A membrane-bound enzyme found in the small intestine.