1. Digestive System
Nutrients: Water, carbohydrates, fats, proteins, vitamins, and minerals.
The Process of Digestion:
The mouth:
1. Teeth which does the mechanical work of digestion by chewing.
2. Saliva- moisten the food and makes it easier to chew. Also starts chemical digestion, with enzymes.

2. The Process of Digestive System
The Esophagus: The food tube- smooth muscles help move food.
The Stomach: a large muscular sac. Chemical digestion, and Mechanical digestion occurring.
The Small intestine: Almost all digestive enzymes are here. Highest amount of chemical digestion and absorption of food occurs here.
Villi- folded surfaces of the small intestine with fingerlike projections, Absorption of nutrients happen here.

3. Digestive system Accessory Structures of Digestion:
Pancreas- Located behind the stomach, two key roles.
1.Produces enzymes
2. Produce Sodium Bicarbonate to neutralize stomach acid.
Liver: located above and to the right of the stomach. It produces bile, that helps dissolve fat.

4. Digestive system
Large Intestine: removes water from undigested material that is left. Waste material that remains passes through and out the rectum.
Digestive disorders:
Constipation
Diarrhea

5. Excretory System
Function: Helps with homeostasis, and remove waste products.
Liver: converts potentially poisonous nitrogen compounds into urea.
Kidneys: removes urea, excess water, and waste from the blood.

6. Excretory system Three steps: 1. Filtration 2. Reabsorption
3. Urine Formation
Kidney Stones:

7. Types of Digestive systems
Monogastric: Consist of one stomach. Examples humans, dogs, hogs.
Ruminant or polygastric: The stomach is divided into four chambers. Examples cows, sheep, and goats.