Human digestive system notes for nursing students

Human Digestive System Simplified Notes for Nursing Students

Introduction to the Digestive System

The digestive system is responsible for breaking down food into simple substances that can
be absorbed and used by the body for energy, growth, and repair.

Main Functions of the Digestive System:

1. Ingestion

Taking food into the mouth.

2. Digestion

Breaking food into smaller molecules.

3. Absorption

Nutrients pass into the bloodstream.

4. Elimination

Removal of undigested waste from the body.

Organs of the Digestive System

1. Mouth

Function:
•Entry point of food
•Teeth help in chewing
•Saliva begins digestion of starch

Important Enzyme: Salivary amylase.

2. Pharynx

Function:

Passage for food from mouth to esophagus

3. Esophagus

Function:

Muscular tube that carries food to the stomach

, Important Point: Food moves by peristalsis.

4. Stomach

Function:

•Stores food temporarily
•Mixes food with gastric juice
•Begins protein digestion

Important Secretions:
•Hydrochloric acid (HCl)
•Pepsin enzyme

5. Small Intestine

Function:
Main site of digestion and absorption

Parts:

1. Duodenum
2. Jejunum
3. Ileum

Important Point: Contains villi for absorption.

6. Large Intestine

Function:

•Absorbs water and salts
•Forms feces

Parts:

•Cecum
•Colon
•Rectum

7. Rectum and Anus

Function: Store and eliminate feces

Accessory Organs of Digestion:

1. Liver