Download The Digestive System

The digestive system
Lecturer:
Anatomy and Physiology
Mrs. Reid-Brown
Group Members:
o Suttiana Allen
I.D#: CH2011
o Douglas Francis
I.D#: CH2008
o Kenroy Campbell I.D#: CH20118389
Parts of the digestive system
The main function of the digestive
system
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The main function is the breakdown of
food into smaller portions, to be
absorbed as nutrients into the
bloodstream, and transferred to the cells
to produce energy, and aid in the
elimination process.
Components of the digestive
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The digestive system consists of the :
Mouth
Esophagus
Stomach
liver
gall bladder
pancreas
small intestine
and a large intestine.
Functions of the digestive system:
Mouth

When food enters the mouth, the salivary
gland releases saliva containing enzymes.
The jaw and teeth, breakdown the food
into smaller pieces, and when swallowed,
moves into the esophagus.
Esophagus

By a wave of muscle contractions
(peristalsis), the food in the esophagus is
pushed into the stomach. The esophageal
sphincter (LES) closes to prevent reentry.
If rejected by the stomach, the esophageal
sphincter, reopen, by contractions, and
force the food back into the mouth, as
vomit.
Stomach

Food passes through four phases.
Chemical digestive juices and enzymes
mix with the food, and is dissolved and
absorbed in the blood. The food is
squeezed by stomach muscles, and
liquefied by the juices.
Liver

The liver has several functions, the main one
is the processing of fat, and liquefied food
rich in nutrients, which is drained from the
small intestines to make it useful. It also
produces sugars from protein, and fatty
substances, releasing albumin and keeping
the blood vessels hydrated with fluids. Toxins
in the blood is converted, and excreted
safely from the body, and calcium used to
reduce acid in the waste.
Gall bladder

Bile is released from the liver into the gall
bladder, and later released into the small
intestine, to dissolve fats.
Pancreas
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The pancreatic duct delivers digestive
juices into the small intestine.
Small intestine

It has three sections, duodenum, jejunum, and ileum. The
duodenum and stomach meets at the pyloric sphincter
preventing material from going back into the stomach. The
duodenum breaks down carbohydrate into sugar, with the
use of enzymes from the pancreas, and liver. Lipase from the
pancreas breaks down fats in the duodenum to produce fatty
acids.
The jejunum absorbs carbohydrates and protein from the
material. Pepsin and amino acids breaks down protein in the
stomach. The ileum absorb fats, and bile salts, vitamins B12,
vitamins in fatty liquids, electrolytes, bile salts, and water
through its pores into the blood. The ileocecal valve, which
joins the ileum and large intestines together prevents the
backward flow of the pasty material into the small intestine.
Large intestine

The large intestine (colon) collects undigested
food. It moves waste from the small intestine to
rectum, passing through the ascending colon, and
transverse colon, and absorbing water through
this process. The waste becomes firm when it
reaches the sigmoid colon, and is designed to
slow down the elimination of the waste, until it is
ready. The rectum stores the waste, and uses the
anal sphincter to prevent release of the waste,
until ready.
Components of the digestive
systems
Summery
References: