digestive system presen.08
DESCRIPTION
Chapter 08 - Digestive SystemTRANSCRIPT
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.