Digestive System Overview and Functions

Digestive System

Provides nutrients, water, and electrolytes to body.

Alimentary Canal

GI tract from mouth to anus.

Accessory Organs

Teeth, tongue, liver, pancreas, gallbladder, salivary glands.

Mucosa

Inner lining that absorbs nutrients.

Submucosa

Contains blood vessels and nerves.

Muscularis externa

Layer that helps move food.

Serosa/Adventitia

Protective outer layer of alimentary canal.

Pharynx

Connects mouth to esophagus, aids swallowing.

Peristalsis

Wave-like muscle contractions moving food.

Stomach

Stores and breaks down food chemically.

Rugae

Folds allowing stomach expansion.

Gastric Glands

Secrete enzymes and acid for digestion.

Chief cells

Release enzymes for protein digestion.

Parietal cells

Produce hydrochloric acid (HCl).

Small Intestine

Main site for digestion and nutrient absorption.

Duodenum

Receives bile and digestive enzymes.

Jejunum

Absorbs nutrients from digested food.

Ileum

Connects small intestine to large intestine.

Plicae circulares

Folds that slow down food movement.

Villi & Microvilli

Increase surface area for absorption.

Large Intestine

Absorbs water, stores waste, makes vitamins.

Cecum

Connects large intestine to small intestine.

Gallstones

Hardened cholesterol blocking bile flow.

Essential Nutrients

Water, protein, carbohydrates, fats, vitamins, minerals.

Gallbladder

Stores bile produced by the liver.

Cirrhosis

Liver scarring from disease or alcohol.

Pancreas

Produces insulin, glucagon, and digestive enzymes.

Amylase

Enzyme breaking down carbohydrates.

Pepsin

Stomach enzyme for protein digestion.

Lipase

Pancreatic enzyme for fat digestion.

Fight-or-flight response

Slows down digestion during stress.