Unit 2: Internal Systems The Digestive System

Digestive System responsible for 4 major functions: 1. ingestion intake of nutrients (eating) 2. digestion the breakdown of food into small soluble molecules a) physical digestion: (ex.) chewing mechanical digestion that cuts food into small pieces smaller pieces increase surface area for enzymes to work on

Digestive System 4 major functions (continued): b) chemical digestion: ex. digestive secretions (saliva) enzymes in digestive juices chemically breakdown food molecules into their monomers (soluble) monomersfood

Digestive System b) chemical digestion: (continued) i) carbohydrates i.e. polysaccharides & disaccharides monosaccharides

Digestive System b) chemical digestion (continued): ii) proteins amino acids

Digestive System b) chemical digestion (continued): iii) lipids

Digestive System 4 major functions (continued): 3. absorption digested nutrients (soluble) absorbed into blood stream or lymphatic system 4. Egestion: removal of solid undigested material (feces) from anus  eating cellulose (fiber) helps ** Excretion (part of the excretory system) removal of liquid soluble waste (urine) from the bladder via urethra

Components of the Digestive System Mouth Esophagus Stomach Small Intestine Large Intestine Rectum Anus Liver Pancreas Gall Bladder digestive tract (alimentary canal) really just a very long tube (~ 9 m long) takes food ~ hours to go through digestive tract

Homework 1. Digestive System Cut Out – start in class 2. “Taking A Look At The Mouth “ label & fill in the missing information will be taken up tomorrow