The Human Digestive System

A comprehensive set of vocabulary flashcards covering the four stages of digestion, key digestive organs, accessory organs, and core biological processes like peristalsis and nutrient absorption.

Ingestion

The initial act of taking food into the mouth.

Digestion

The chemical and mechanical breakdown of food into smaller, manageable pieces.

Absorption

The stage where nutrients pass through the intestinal walls and into the bloodstream to nourish the body.

Elimination

The final process of removing undigested food and waste products from the body.

Mouth

The site where digestion starts; uses teeth for mechanical breakdown and saliva to introduce enzymes for carbohydrate breakdown.

Amylase

An enzyme found in saliva that begins the chemical breakdown of carbohydrates.

Esophagus

A muscular tube that moves food toward the stomach using peristalsis.

Peristalsis

A series of involuntary, wave-like muscle contractions or "squeezing" motions that ensure food and liquid move forward through the digestive tract.

Stomach

An organ where food is mixed with gastric juices and strong acids, protected by a thick mucus layer.

Small Intestine

The primary site for nutrient absorption, utilizing tiny, finger-like projections to maximize surface area.

Villi and microvilli

Tiny, finger-like projections in the small intestine that maximize the surface area for taking in nutrients.

Large Intestine

An organ whose main job is to absorb water from remaining waste, transforming liquid remnants into solid stool.

Rectum

The part of the digestive system that stores stool until the body is ready for a bowel movement.

Anus

The opening through which waste is expelled from the body.

Liver

An accessory organ that produces bile to help digest fats and vitamins.

Bile

A substance produced by the liver specifically designed to help digest fats and vitamins.

Gallbladder

A small pouch located under the liver that stores bile and releases it when you eat.

Pancreas

An accessory organ that creates digestive juices filled with enzymes to break down proteins, fats, and carbohydrates.

Enzymes

Specialized proteins that act as catalysts, significantly speeding up the chemical reactions needed to break down complex food molecules.

Complete Digestive System

A "tube-like" digestive tract with two separate openings—one for intake (mouth) and one for waste (anus)—ensuring a one-way flow of food.