The Digestive System

Main goal of the Digestive system: The main goal of the Digestive System is to break down food so that your body can use it!

Describe the digestive system The digestive tract is a series of hollow organs joined in a tube from the mouth to the anus. Accessory organs include the liver, gall bladder, and pancreas. Food does not pass through these organs.

Identify the organs of the digestive system

The 7 stops of the Digestive System…

Stop #1 Mouth Teeth bite off and chew food into a soft pulp that is easy to swallow. Chewing mixes the food with saliva, from salivary glands around the mouth and face, to make it moist and easy to swallow.

Mouth physically and chemically breaks down the food Mouth (cont’d)… Mouth physically and chemically breaks down the food

Stop #2 Esophagus The esophagus is a muscular tube. It takes food from the throat and pushes it down through the neck, and into the stomach.

It moves food by waves of muscle contraction called peristalsis.

Stop #3 Stomach The stomach has thick muscles in its wall. These contract to mash the food into a water soup called chyme. The stomach lining produces strong digestive juices.

Stomach cont’d The stomach does not digest itself because it has a protective layer of mucus lining the walls.

Stop #4 Small Intestine This part of the digestive tract is narrow, but very long - about 20 feet. Enzymes continue the chemical reactions on the food by breaking the food down even further.

Small intestine contd’… The nutrients are broken down small enough to pass through the lining of the small intestine, and into the blood (diffusion).

Stop #5 Large Intestine Substances that were not absorbed in the small intestine, such as spare water and minerals, are absorbed through the walls of the large intestine, back into the blood.

Large intestine cont’d… The remains are formed into solid feces, ready to be removed from the body

Stop #6 and #7 Rectum and Anus The end of the large intestine, the rectum, stores the feces. Feces are finally released through the anus, and out of the body.

“Accessory” organs 3 Accessory organs: 1. Pancreas 2. Liver 3. Gall bladder

Accessory Organs Pancreas- makes digestive juices called enzymes which help to digest food further as it enters the small intestines.

Liver- like a food-processing factory. Produces a digestive juice called bile Gall Bladder- A small baglike part under the liver. It stores bile.

Labeling Practice Esophagus Liver Stomach Gall Bladder Pancreas Mouth Esophagus Liver Stomach Gall Bladder Pancreas Large Intestine Small Intestine Appendix Rectum Anus