DIGESTIVE SYSTEM

STRUCTURES & FUNCTIONS

DIGESTION The process of

changing complex foods into simpler soluble forms that can be used by the body

DIGESTION ENZYMES AMYLASE-breaks

down starches into glucose( saliva)

LIPASE- breaks down fats into fatty acids & glycerol

Digestion ENZYMES TRYPSIN-breaks down protein into

amino acids

Structures Alimentary canal GI tract, or digestive tract Consists of: oral cavity, pharnyx,

esophagus, stomach, small intestine, and large intestine.

Continuous tube about 30 feet in length, from mouth to anus.

Digestive tract

ACTUALHUMANABDOMINALCAVITY

Oral cavity- pharynx Teeth= mastication Tongue= taste, mastication,

swallowing Salivary glands

Mechanical breakdown of food into bolus

Chemical breakdown: amylase breaks down starches to glucose

Esophagus 10 inches long Carries bolus to stomach Muscles in the upper third of the

esophagus are voluntary = swallowing

Muscles in the lower portion is involuntary=peristalsis

Stomach

Sections Fundus= upper portion Body = mid section Pylorus= lower portion Sphincters: cardiac-located

between the esophagus and stomach Pyloric: located between the stomach

and small intestine.

Small intestine 3 sections Duodenum= first 12 inches Jejunum= mid section- about 8 ft. Ileum= last section- 10-12 ft longABSORPTION OF NUTRIENTS occurs in

the small intestine

Large intestine Sections

Ascending colon – right side Transverse colon- across the abdomen Descending colon- left side Sigmoid colon- very bottom section just

superior to anus

Accessory Organs Liver: produces bile, stores

sugar(glycogen), stores iron and certain vitamins, produces cholesterol, heparin, and blood protiens to aid in blood clotting, detoxifies harmful substances taken in by the blood

Gall Bladder: stores bile for release into duodenum for emulsification of fats

Pancreas: releases enzymes into duodenum for further breakdown of chyme.