1. Body Systems and Homeostasis 2
Nutrient Extraction and Excretion
-the digestive system allows for nutrient extraction from food and the excretory system allows for excretion of non-gaseous waste
-it is made of the digestive tract and other accessory organs
1. digestive tract: a muscular
tube that food travels
through
2. accessory organs: help
break down food

2. Digestive Tract
Path of the digestive tract: mouth  esophagus  stomach  small intestine  large intestine
-as food travels through the digestive tract, it continually broken down
-the mouth breaks food
down into smaller pieces
-the stomach continues to
break down those pieces

3. Digestive Tract
-chemical digestion mostly occurs through the help of enzymes
-there are digestive enzymes throughout the digestive tract found in the mouth, stomach, and intestines
-enzymes and acid are secretions produced by:
-salivary glands (amylase in saliva)
-stomach (hydrochloric acid)
-pancreas (lipase, amylase)
-liver (bile, protease)

4. Digestive Tract
-food travels from the stomach to the small intestines where 90% of absorption occurs
-lining of the small intestines has villi and lots of blood vessels for absorption of nutrients which are taken to cells through the circulatory system

5. Digestive Tract
-the large intestines is where water is absorbed and feces is compacted for excretion
-the end of the digestive tract is the rectum and anus which requires a strong muscle contraction for excretion

6. Body Systems and Homeostasis 2
-non-gaseous waste is carried leaves the cells via the circulatory system and brought to the kidneys and eventually excreted out
-one common waste product is nitrogen from the breakdown of amino acids which produces ammonia (toxic) and is converted water-soluble urea

7. Body Systems and Homeostasis 2

8. Compare and Contrast
Compare how homeostasis works with the respiratory system and the circulatory system with how homeostasis works with the respiratory system and the digestive system:
Respiratory &
Circulatory
Digestive
& Circulatory