The Digestive System A Study Guide Ms. Bennett’s Living Environment

A Study Guide

Ms. Bennett’s Living Environment

The purpose of the Digestive System To make big things into small things

To make big things into small things

The Parts of the Digestive System

The Mouth Teeth grind food into swallowable substance (bolus) Mechanical and chemical digestion take place here Enzymes in saliva start to break down starches.

Teeth grind food into swallowable substance (bolus)

Mechanical and chemical digestion take place here

Enzymes in saliva start to break down starches.

Esophagus Muscular contractions move the bolus to the stomach These contractions are called peristalsis No new digestion occurs

Muscular contractions move the bolus to the stomach

These contractions are called peristalsis

No new digestion occurs

Stomach Stomach is very muscular and churns the food into a paste (chyme). Stomach makes acid which helps break down proteins.

Stomach is very muscular and churns the food into a paste (chyme).

Stomach makes acid which helps break down proteins.

Small Intestine No new mechanical digestion takes place Enzymes break down proteins, starches, and fats Nutrients are absorbed into the bloodstream via the villi.

No new mechanical digestion takes place

Enzymes break down proteins, starches, and fats

Nutrients are absorbed into the bloodstream via the villi.

Large Intestine Undigested food (now called feces) passes into the large intestine. Water, minerals, and vitamins are reabsorbed.

Undigested food (now called feces) passes into the large intestine.

Water, minerals, and vitamins are reabsorbed.

Anus/Rectum The rectum stores feces until it is ready to be released. The anus is the opening through which feces is released.

The rectum stores feces until it is ready to be released.

The anus is the opening through which feces is released.

Types of Digestion Part Mechanical Chemical Mouth Chewing Enzymes from saliva Esophagus None None (still continuing from mouth) Stomach Churning of Food Acid from gastric juice Small Intestine None Enzymes Large Intestine None Reabsorption of water and minerals

Enzymes Enzymes are chemicals that speed up chemical reactions. Enzymes used in digestion help break big things into small things. 3 types of enzymes Proteases - act on proteins Amylases - act on starch Lipases - act on fats

Enzymes are chemicals that speed up chemical reactions.

Enzymes used in digestion help break big things into small things.

3 types of enzymes

Proteases - act on proteins

Amylases - act on starch

Lipases - act on fats