Download DIGESTIVE SYSTEM

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
ACTUAL
HUMAN
ABDOMINAL
CAVITY
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 long
ABSORPTION 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.