Mechanical digestion begins in the mouth as the food is chewed
Chemical digestion begins in the mouth when food mixes with saliva
Saliva contains an enzyme (amylase) that begins the breakdown of carbohydrates
The epiglottis is a flexible flap at the end of the larynx in the throat.
It acts as a switch between the larynx and the esophagus
to permit air to enter the airway to the lungs and food to pass into the esophagus
esophagus it is a muscular tube connecting the throat with the stomach.
The esophagus is about 8 inches long.
The esophagus muscle acts with peristaltic action
to move swallowed food down to the stomach
The food then enters the stomach
which is a rounded, hollow j shape organ
Located between the esophagus and the duodenum
the stomach has three mechanical tasks to do
First, the stomach must store the swallowed food and liquid
This requires the muscle of the upper part of the stomach
to relax and accept large volumes of swallowed material
The inner layer of the stomach is full of wrinkles known as rugae
Rugae both allow the stomach to stretch in order to
accommodate large meals and help to
grip and move food during digestion.
The second job is to mix up the food
liquid, with digestive juice produced by the stomach
The lower part of the stomach mixes these materials as a blender
by its muscle action. and breaks down
the food to tiny particles in 3 milimiters
finally, the stomach empties this acidy mash slowly into the small intestine
The small intestine or small bowel is an organ
in the gastrointestinal tract where most of the end absorption of
nutrients and minerals from food takes place
It lies between the stomach and large intestine
Duodenum, the first part of the small intestine
which receives partially digested food from the stomach
and begins the absorption of nutrients
The duodenum is the shortest segment of the intestine
and is about 23 to 28 cm (9 to 11 inches) long
The pancreatic juices and bile that are released into
the duodenum help the body to digest fats, carbohydrates, and proteins
The food is in instetin now and have very long way to go
As a person grows the small intestine increases 20 times in
length from about 200 cm in a newborn to almost 6 m in an adult
The inner walls of the small intestine show mucosal folds.
These are called the plicae circulares
The plicae are more numerous in the early and
educe in numbers in the later part and are completely absent
Digestion is important because your body needs nutrients
from food and drink to work properly and stay healthy
Proteins, fats, carbohydrates, vitamins , minerals, and water are nutrients
Your digestive system breaks nutrients into parts small enough
for your body to absorb and use for energy
growth, and cell repair
What is left over, which is mostly liquid
then moves into the colon
The water is absorbed in the colon
Bacteria in the colon break down the remaining material
Then the colon moves the leftover
material into the rectum
the rectum is like a storage-holder for this waste
Muscles in the rectum move the waste, called stool
out of the body through the anus