PP 979-991 DIGESTIVE SYSTEM

FUNCTION Breakdown of food into simpler molecules that can be absorbed by the body in one long tube from mouth to anus

NUTRIENTS 6 classes of nutrients: carbohydrates fats proteins

NUTRIENTS 6 classes of nutrients: carbohydrates fats proteins minerals: help balance osmosis and the function of certain cells (i.e muscle and nerve cell) vitamins: aid enzyme activity water: most chemical reactions can only occur in water (accounts for half of your body weight)

Mechanical vs. Chemical Digestion Mechanical: physical breakdown of food Chewing, peristalsis (moving bolus down the esophagus), and stomach churning

Mechanical vs. Chemical Digestion Chemical Digestion: Enzymes breaking down food into simpler forms (monomers)

DIGESTIVE TRACT MOUTH AND ESOPHAGUS Amylase (enzyme) is released from glands into saliva Breaks down carbs to monosaccharides

DIGESTIVE TRACT MOUTH AND ESOPHAGUS Amylase (enzyme) is released from glands into saliva Breaks down carbs to monosaccharides Bolus (food ball) travels down esophagus to stomach

STOMACH Muscle contractions break bolus apart (mechanical digestion) Pepsin (enzyme) breaks down proteins into amino acids Released by gastric glands HCl keeps stomach acidic so the pepsin can work

PANCREAS Secretes sodium bicarbonate (base) into small intestine to neutralize acid.

LIVER Produces bile and stores it in the gall bladder

GALL BLADDER Stores bile and secretes it into the small intestine Breaks down fats into fatty acids

SMALL INTESTINE Chemical digestion and nutrient absorption

SMALL INTESTINE Chemical digestion and nutrient absorption Villi: Folds in lining of small intestines Increases surface area for maximum absorption.

LARGE INTESTINE/COLON Absorption of water, minerals, and vitamins

Salivary glands Esophagus Liver Stomach Pancreas Gall bladder Large intestine/colon Small intestine