The Digestive System

IntroductionThe digestive system

is used for breaking down food into nutrients which then pass into the circulatory system and are taken to where they are needed in the body.

IntroductionThere are four stages to

food processing:1. Ingestion: taking in

food2. Digestion: breaking

down food into nutrients

3. Absorption: taking in nutrients by cells

4. Egestion: removing any leftover wastes

The Digestive SystemPurpose: to convert food particles into simpler micro-molecules that can be absorbed into the bloodstream and used by the body.Major Organs and their Functions:Mouth – to chew and grind up food - saliva also begins the chemical breakdownEsophagus – pipe connecting mouth to stomachStomach – secretes an extraordinarily strong acid (pH = 2) that

leads to breakdown of food - once the food is broken down in the stomach and mixed with digestive juices, it is called chyme

Pancreas – produces the hormone insulin that regulates blood sugar levels -- also help neutralize stomach acid

Liver – produces bile, which breaks down fats in foodsGallbladder – pouch-like organ that stores bile for future useSmall Intestine – after digestion is complete, the chyme enters the mall intestine where it is absorbed into the bloodstream

-- the chyme is propelled along by folded surfaces called villi, on the intestineLarge Intestine – removes water from the chyme and gets the waste ready for excretionRectum – Stores all leftover waste in compacted form at the end of the large intestine.Anal sphincter - When full, the anal sphincter loosens and the waste, called feces, passes out of the body through the anus.

The Digestive System