The Digestive System 6 th Grade Life Science

Major Functions of the Digestive System Break down ingested food Put nutrients into the bloodstream Remove waste from the body

Organs of the Digestive System Mouth- teeth, salivary glands, tongue Esophagus Stomach Small Intestine Large Intestine Pancreas Liver Gall bladder Accessory Organs

Mouth Digestion begins here! Teeth and tongue are used in mechanical digestion- physical breakdown of food Saliva and enzymes begin chemical digestion- chemical breakdown of food

Esophagus Muscular tube that connects mouth to stomach Moves food downward by peristalsis, or muscular contractions Epiglottis seals off windpipe during swallowing to prevent choking

Stomach- Mechanical and Chemical Digestion Muscular pouch that expands to hold your food Hydrochloric acid (HCl) and the enzyme pepsin combine to form gastric juice A gummy coating of mucus protects the stomach lining from the strong chemicals Chyme, a thick liquid containing partially digested food, is produced here

Small Intestine Most chemical digestion occurs here! Inner surface is covered in villi and microvilli, millions of tiny finger-like projections that absorb nutrient molecules from the chyme The villi create a large surface area so as many nutrients as possible can be a absorbed Longest portion of the digestive tract

Large Intestine No digestion occurs here Water is absorbed from remaining food Bacteria feed on material passing through and produce Vitamins (K) vital to our health Waste material, feces, is prepared for elimination from the body

Rectum Stores feces until they can be expelled through the anus.

The End!