Digestive System: Systems & Stages

This set of vocabulary flashcards covers the levels of organization, the four stages of human digestion, and the specific structures and functions of the digestive system based on the lecture notes.

Levels of Organization

The hierarchical structure of the body where organ systems are made of organs, which are made of tissues, which in turn are made of cells.

Epithelial tissue

Tissue that lines the intestinal tract and secretes mucus.

Connective tissue

Tissue located between muscles that contains blood vessels.

Muscle tissue

Smooth muscle that helps move food through the digestive system with contractions.

Nervous tissue

Tissue that transports electrical stimulus between the digestive system and the brain.

Gastrointestinal tract (GI tract)

The canal through which food and liquids flow, measuring approximately $7-9\,m$ long in the adult human.

Digestion

A series of steps involved in taking in food, breaking it down into smaller pieces, absorbing nutrients, and eliminating wastes.

Ingestion

The voluntary act of eating or drinking that occurs in the mouth.

Mechanical digestion

The physical breakdown of food into small molecules through chewing, cutting, and mashing.

Bolus

A ball of food created by mechanical digestion (chewing, cutting, and mashing).

Chemical digestion

The involuntary breakdown of food into small molecules using enzymes.

Absorption

The movement of digested nutrients and water from the GI tract into the blood capillaries.

Elimination (Egestion)

The removal of undigested solid waste from the body, utilizing both voluntary and involuntary control.

Incisors

Specialized teeth used for cutting food.

Canine

Specialized teeth used for tearing food.

Premolars

Teeth specialized for grinding food.

Molars

Teeth specialized for crushing food to increase surface area for chemical digestion.

Amylase

An enzyme found in saliva that breaks down starches into simpler carbohydrates.

Peristalsis

Rhythmic contractions of smooth muscles in the esophagus wall that move food from the mouth to the stomach.

Pepsin

An enzyme in the stomach that performs chemical digestion by breaking food down into amino acids.