The Digestive System

Path of the Digestive System

ØMouth

ØEsophagus

ØStomach

ØSmall Intestine

ØLarge Intestine

ØRectum

 

 

The Mouth

ØWhere digestion begins

ØTwo types digestion occur:

lMechanical – breaking down of food into smaller pieces with teeth

lChemical – the breaking down of complex molecules into simpler one by the enzymes in saliva

•An enzyme is a protein that speeds up chemical reactions.

The Esophagus

ØA muscular tube that connects the mouth to the stomach

lEpiglottis – flap of tissue preventing food from entering trachea

lPeristalsis – involuntary muscular contractions that move food down the esophagus

The Stomach

ØA J-shaped muscular pouch

lHolds about 2 liters of food

lBoth mechanical and chemical digestion take place as stomach churns food in digestive juices.

•Contains enzyme Pepsin and Hydrochloric Acid

 

 

The Small Intestine

ØMakes up about 2/3 of the digestive system.

ØWhere almost all chemical digestion and absorption of nutrients takes place.

ØContain millions of tiny finger-like structures called villi where the absorption takes place.

 

Other Digestive Organs

ØLiver

lHeaviest organ of the body

lProduces bile to break down fat

ØGallbladder

lHolds bile until it is needed in the small intestine

ØPancreas

lTriangular shape

lProduces insulin to break down sugars

 

The Large Intestine

ØLast section of the digestive system

ØWater is absorbed, and remaining material readied for elimination from body.

ØLast section is known as the rectum.