Chapter 25: The Digestive System

What are the five stages of the digestive process?

1. Ingestion 2. Digestion 3. Absorption 4. Compaction 5. Defecation

What is the digestive system responsible for?

Processing food, extracting nutrients, and eliminating waste.

What organs make up the digestive tract?

Mouth, pharynx, esophagus, stomach, small intestine, and large intestine.

What is the role of saliva in digestion?

Saliva contains enzymes like salivary amylase and salivary lipase that initiate chemical digestion.

What is chyme?

A watery mixture of semi-digested food produced in the stomach.

How does the stomach protect its lining?

Through a mucous coat, tight junctions, and rapid cell replacement.

What is the function of the gall bladder?

To store bile until it is released into the small intestine.

What hormones are secreted by the pancreatic islets?

Insulin and glucagon.

What are the components of pancreatic juice?

Water, electrolytes, sodium bicarbonate, and digestive enzymes.

What is the primary function of the small intestine?

Most digestion and nutrient absorption occur in the jejunum.

What is motilin and its function in the small intestine?

A hormone released by the SI that causes waves of peristalsis called the migrating motor complex.

Which enzymes are involved in protein digestion?

Pepsin, trypsin, chymotrypsin, carboxypeptidase, amino-peptidase, and dipeptidase.

How are lipids absorbed in the body?

Fatty acids are absorbed by lacteals and travel through the lymph system to the circulatory system.

What is the main function of the large intestine?

Reabsorption of water and electrolytes, and compaction of waste into feces.

What happens to carbohydrates during digestion?

Starch is broken down into glucose, which is absorbed by the small intestine.

What role does bile play in fat digestion?

Bile separates fat molecules, allowing pancreatic lipase to digest them more efficiently.