digestive system presen.08

D I G E S T I V E

by

Beatriz

S Y S T E M

Main functions of the digestive system:

Digesting food

Absorbing nutrients

Eliminate waste

The digestive system is also known as the

gastrointestinal (GI) system.

FUNCTION

The digestive system begins breaking

down food through mechanical and

chemical digestion. After being digested,

nutrient molecules are absorb into the

body and enter the blood stream. Any

food not digested or absorbed is

eliminated as solid waste.

ORGANS

COLON

ESOPHAGUS

GALLBLADDER

LIVER

ORAL CAVITY

PANCREAS

PHARYNX

SALIVARY GLANDS

SMALL INTESTINE

STOMACH

When does the digestion begins?

Digestion begins in the

mouth. The saliva

contains digestive

enzymes to break down

carbohydrates and

slippery lubricants to

make food easy to

swallow.

ORAL CAVITY Taste buds is found on the

surface of the tongue, can

distinguish the bitter, sweet, sour,

and salty flavors in our food.

Hanging down from the posterior

edge of the palate (roof of the

mouth) is the uvula which provide

the speech production and help

to help to prevent food from

entering the lungs.

TEETH

Teeth are an important part of the first stage of digestion.

The teeth in front of the mouth helps to bite, tear, or cut food into small pieces.

INCISORS CUSPIDS (CANINES)

The remaining posterior teeth grind and crush food into even finer pieces.

BICUSPIDS (PREMOLAR) MOLARS

PHARYNX When food is swallowed,

it enters the oropharynx

and then the

laryngopharynx.

The epiglottis is a

cartilaginous flap that

folds down to cover the

larynx and trachea,

preventing food from

entering the respiratory

tract and instead

continues into the

esophagus.

ESOPHAGUS The esophagus is a

muscular tube of

about 10 inches long

in adults.

Food entering the

esophagus is carried

through the thoracic

cavity and diaphragm

and into de abdominal

cavity where it enters

the stomach.

STOMACH

It is a J-shaped muscular organ that acts as a bag or sac to collect and churn food with digestive juices, is composed of three parts

FUNDUS (upper region) BODY (main portion) ANTRUM (lower region)

Rugae: Foldings in the lining of the stomach

When the stomach fills with food the rugae stretch out and disappear.

Hydrochloric acid is secreted by glands in the mucous membrane lining of the stomach.

Foods mixes with hydrochloric acid and other gastricjuices to form a liquid mixture called chyme.

Food is propelled along the esophagus by wavelike muscular contractions called peristalsis.

Small intestine

The small intestine, or small bowel, is the major site of digestion

and absorption of nutrients from food.

It is located between the pyloric sphincter and the colon. The sigmoid

colon curves in an S-shape back to the midline of the body and ends at

the rectum, where the feces are stored. It has three sections:

DUODENUM

JEJUNUM

ILEUM

ACCESSORY ORGANS OF THE DIGESTIVE SYSTEM SALIVARY GLANDS

Helping in the oral cavity produce saliva, which allows food to be swallowed without chocking.

LIVERProcess the nutrients absorbed by the intestines, detoxifying harmful substances in the body and producing bile which is important for the digestion of fats and lipids.

GALLBLADDERA small organ located just under the liver. It functions to store the bile produced by the liver.

PANCREASAlso an endocrine gland that produces the hormones insulin and glucagon, which play a role in regulating the level of glucose in the blood.