04 Digestion and Digestive System Anatomy

Question 1

Types of Digestion

Answer 1

Mechanical Digestion: Physical breakdown of food (e.g., chewing).

Chemical Digestion: Breakdown of food at a molecular level (e.g., enzymes breaking down carbohydrates).

Question 2

Mouth

Answer 2

Function: Start of digestion (ingestion and mechanical digestion via teeth, chemical digestion via saliva).

Saliva: Has enzymes and contains amylase to break down carbohydrates and mucus to moisten food.

Salivary glands produce saliva and amylase

Amylase breaks down complex carbohydrates into disaccharides

Bullous (the ball of food) pushed to the back and down the esophagus

Question 3

Esophagus

Answer 3

Function: Tube connecting the mouth to the stomach, moving food via peristalsis (muscle contractions).

Epiglottis: Prevents food from entering the lungs during swallowing.

Question 4

Stomach

Answer 4

Function: Churns food to create chyme using acid (HCl), starts protein breakdown.

Churning creates chemical digestion of pepsin/protease which breaks down proteins into peptides

Stomach folds (rugae): Allow expansion + muscular walls for churning food.

Sphincters: Control food entry and exit (cardiac and pyloric sphincters).

Question 5

Small Intestine

Answer 5

Function: Major site of nutrient absorption.

Peptidase break down peptides into amino acids

Mucus helps move and break down nutrients

Sections:

Duodenum: Digestion continues, contact with Pancreatic Amylase and Pancreatic Lipase (with bile)

Jejunum: Digestion finishes, absorption starts.

Ileum: Absorption of nutrients.

Question 6

Large Intestine (Colon)

Answer 6

Function: Absorbs and breaks down water and nutrients

Egestion: Remaining materials, like cellulose, are expelled from the body.

Question 7

System Interaction

Answer 7

Digestive System provides nutrients to other organ systems

Question 8

Stomach
Sphincters

Answer 8

sphincters: a ring of muscle at each end of the stomach

Cardiac/esophageal sphincter: located between the esophagus and the top of the stomach

Pyloric sphincter: located between the stomach and the start of the small intestine (duodenum)

Sphincters control the passage of food into and out of the stomach