Human Body Digestive System

Functions Break down food (digest) Take in food (ingest) Absorb nutrients from food Eliminate (get rid of) solid waste

DIGESTION The process of breaking down food into a form that the body can use Large molecules into smaller ones!

Mechanical and Chemical 2 Types of digestion Mechanical and Chemical

Mechanical Digestion Food is chewed, mixed and churned. Takes place in the mouth and stomach

Chemical Digestion Chemical reactions that break down large molecules into smaller molecules that can be absorbed by cells Examples: saliva in mouth acids & enzymes

ORGANS Major Organs: Mouth Esophagus Stomach Small Intestine Large Intestine Rectum Anus Accessory Organs: Tongue Teeth Salivary Glands Liver Gallbladder Pancreas

Mouth 1. Digestion begins 2. Mechanical (teeth and tongue) & Chemical (saliva) digestion 3. Saliva mixes with food to produce a soft mass called a Bolus

Esophagus 1. No digestion takes place 2. Peristalsis-muscle contractions (squeezing) that helps move food down the esophagus and through the digestive tract

Stomach 2. Produces HCl (hydrochloric acid) and mucus 1. Mechanical (churning) and chemical digestion 2. Produces HCl (hydrochloric acid) and mucus 3. Becomes a substance called chyme (kime), A thin watery product

Small Intestine 1. Major portion of all digestion occurs in the duodenum 2. Digestive juices from the liver, gall bladder (bile) and pancreas are added 3. Villi-make the surface larger so there are more places for food and nutrients to be absorbed

VILLI Real above Scientific illustration right

Large Intestine 1. Absorbs water from the chyme 2. Chyme may stay in the large intestine for up to 3 days

Rectum and Anus Chyme makes its way out of the body, usually as “solid” waste… compacted in the rectum and expelled from the anus.