The Digestive System

Chemical change turns food into a new form: a form that cells can use.

Digestion is the process of changing food into a form usable by the cells of the body

Where does digestion begin?

Digestion begins in the mouth.

What role does saliva play in digestion?

Enzymes in saliva help to break down food. Salivary amylase begins digestion by breaking down starches.

What are enzymes?

Enzymes are chemicals that speed up the rate of chemical change by breaking down food.

What mashes and cuts food in your mouth?

Your teeth mashes and cuts food in your mouth.

What moves food through to your stomach?

The esophagus moves food from the back of the throat through to the stomach by a process called peristalsis.

Peristalsis

What is the baglike, muscular organ that mixes and chemically changes protein?

The stomach is the muscular organ that mixes and chemically changes protein.

When they reach the stomach, mashed-up food particles mix with gastric juice.

What type of acid breaks down food in your stomach?

Gastric juice contains hydrochloric acid, which breaks down food in your stomach.

The mashed up food moves from the stomach to the small intestine.

Sphincters

Where does most digestion in the small intestine take place?

Most digestion takes place in the small intestine. In the small intestine, the duodenum does most of the digestion.

How long is the small intestine?

The small intestine is seven meters (22 feet) long.

What organs produce enzymes that help in digestion?

The pancreas and the liver produce enzymes that help in digestion.

The liver’s role is to _____.

1. Remove harmful substances from the blood

2. Make bile, which is used in digestion to break up fats

3. Control blood sugar levels

Your food can spend up to 4 hours in the small intestine.

Food passes from the small intestine into what organ?

Food passes from the small intestine into the large intestine.

What is the main role of the large intestine?

The main role of the large intestine is to absorb water from waste.

The large intestine measures about 5 feet long.

After leaving the large intestine, waste is removed from the body via the rectum and anus.

Under normal circumstances, it takes 21 hours for food to pass entirely through the digestive system of a healthy human.