General Science - Digestive System

(09-22-2025)

Digestive System

It breaks down the food we eat, allowing the food to be absorbed by the blood and used throughout our body as source of energy.

Ingestion, Digestion, Absorption, and Elimination

Four processes of the digestive system

Ingestion

The taking in of food in our mouth.

Digestion

The four biomolecules are broken down.

Absorption

The four biomolecules are absorbed and delivered on to the other parts of the body

Elimination

Waste are being removed by defacation.

Mechanical and Chemical Digestion

Two types of digestion:

Mechanical Digestion

Breaks down the food through physical forces.

Chemical Digestion

It uses chemical reactions to break down the food.

Mouth

Chews the food and mixes it with saliva.

Esophagus

A long tube that pushes food down to the stomach using wave-like movements.

Peristalsis

The wave-like movements in the esophagus is called ________.

Cardiac Sphincter

Found at the end of the esophagus that allows the food to enter stomach.

Stomach

A muscular “mixing bag.” It churns food and mixes it with gastric juices (acid and enzymes) to turn it into a semi-liquid.

Chyme

A semi-liquid in the stomach after it churns food and mixes it with gastric juices is called _______.

Pyloric Sphincter

Found at the end of the stomach that allows the food to enter small intestine.

Small Intestine

A long, coiled organ where most digestion and absorption happen.

3m

The small intestine is about __ long

Duodenum

Upper part. It has wider diameter.

Jejunum

Great diameter and thicker walls.

Ileum

Narrow diameter and highly coiled.

Intestinal villa

The _______ _______ is found in the Ileum; where absorption completes

Large Intestine

It takes the liquid waste from the small intestine, dries it into solid waste (stool) through water absorption, and then stores and expels the waste product through the rectum and anus.

Ascending, Transverse, and Descending Colon

Three Parts of the Large Intestine:

Rectum

______ collects and holds feces

Anus

The _______, the body's final digestive opening, uses sphincter muscles to control the release of stool