Standard 4.1 Explain generally how the digestive system (mouth, pharynx, esophagus, stomach, small and large intestines, rectum) converts macromolecules from food into smaller molecules that can be used by cells for energy and for repair and growth.
Vocabulary
Absorption - when the intestines take in nutrients and water into the blood
Villi - microscopic region of the intestines where water and nutrients are absorbed into the blood stream
Digestive System
This system has three chores:
1. Break down food
2. Absorb the nutrients (carbs, lipids, proteins, nucleic acids)
3. Eliminate solid waste
*The organs involved in food break down are: mouth (teeth, tongue, saliva), stomach, liver, gall bladder, pancreas, small intestine and (the esophagus just transports the food to the stomach when you swallow)
*The organs that absorb nutrients are: the small intestines and the large intestines (absorbs water)
*The organs that eliminate waste are the large intestine (colon) and rectum
Below you can see how the liver and the gall bladder make bile and dump it into the small intestine called the duodenum. The pancreas dumps its juice into the duodenum as well. The stomach moves the partially digested food into the duodenum too.
Break down of Carbs, Proteins and Lipids
1. Carbohydrates - break down in the mouth with saliva and in the duodenum by the pancreatic enzymes
2. Proteins - break down in the stomach by enzymes
3. Lipids - break down in the duodenum using bile.
Bile is made by the liver and stored in the gall bladder