This document provides an overview of the digestive system and its organs. The digestive system includes the mouth, throat, esophagus, stomach, small intestine, large intestine, pancreas, liver, and gallbladder. Food passes through these organs as it is broken down by mechanical and chemical digestion. Glands and organs secrete enzymes and hormones like gastrin, cholecystokinin, and secretin to further break down food into nutrients that can be absorbed and used for energy. The summary highlights the key organs of the digestive system and the multi-step process of digesting food through different stages until nutrients are absorbed for use by the body.

1. Ministry of High Education
Almajmaa University
College of Medicine

4. Digestive System
Your digestive system is turn the food you eat into
energy your body needs to survive
The organ of digestive system are :
Mouth
Throat
Esophagus
Small Intestine
Large intestine
Pancreas
Liver
Gallbladder

5. mouth :
 The mouth is the beginning of
the digestive tract .
 Chewing and breaks the food
into pieces that are more easily
digested.
Throat :
 Also called the pharynx
 the throat is the next site for
food you've eaten. From here,
food travels to the esophagus .

6. Esophagus :
The esophagus is a
muscular tube extending
from the pharynx to the
stomach .
 By means of a series of
contractions, called
peristalsis the esophagus
delivers food to the
stomach .

7. Stomach :
• The stomach is a sac-like
organ with strong muscular
walls
• In addition to holding the
food, it's also a mixer and
grinder .
• The stomach secretes acid
and powerful enzymes that
continue the process of
breaking down the food.
• When the food leave the
stomach it is look like liquid
or paste .

8. Small intestine :
 Made up of three parts :
duodenum, jejunum, and
ileum .
 the small intestine is a long
tube loosely coiled in the
abdomen The small intestine
continues the process of
breaking down food by using
enzymes released by the
pancreas and bile from the liver.
 Bile is a compound that aids in
the digestion of fat and
eliminates waste products from
the blood.

9. • Large intestine : The
large intestine (colon) is
the last part of the
digestive system.
• Its function is to absorb
water from the remaining
indigestible food matter,
and then to pass useless
waste material from the
body by Rectum then
anus.

10. Pancreas : Among other functions,
the pancreas secretes enzymes
into the small intestine. These
enzymes break down protein, fat,
and carbohydrates from the food
we eat .
Liver : has many functions, but two
of its main functions within the
digestive system are :
 make and secrete bile
 cleanse and purify the blood
coming from the small intestine
containing the nutrients just
absorbed .

11.  Gallbladder : The
gallbladder is a pear-shaped
reservoir that sits just under
the liver and stores bile.
 Bile is made in the liver then
travels to the gallbladder
through a channel called the
cystic duct.
 During a meal, the gallbladder
contracts, sending bile to the
small intestine.

13. What is gastro-intestinal hormones ?
• The GI hormones are secreted by epithelial
cells lining the lumen of the stomach and
small intestine .
• GI hormones are secreted into blood .
• they affect function of other parts of the
digestive tube , liver, pancreas, brain .

14. Hormones
source
function
Gastrin
secreted by the
mucous lining of the
stomach
the secretion of gastric
acid is stimulated
Cholecystokinin
in the small intestine
that stimulates the
secretion of pancreatic
enzymes
Secretin
into the small
intestine
that stimulates the
secretion of water and
bicarbonate from the
pancreas
Motilin
in the stomach and
small intestine
controlling smooth
muscle contractions
Gastric
inhibitory
peptide
in the small intestine
Inhibits gastric
secretion

15. summary
The digestive system is one of the most
important system in the body, the organ of the
GI system digest the food which is the source of
energy .
Food passes through several stages (Mouth pharynx- esophagus – stomach – small intestine
- large intestine ) to Absorption of nutrients
With the help of enzymes .

16. Questions ?

17. Resources
• GUYTON AND HALL textbook of Medical
physiology .
• Medicine books web site.

18. Thank you
Don by : Mohammed Abdullah Hazazi
2nd year medical student
Supervisor : DR. Kamran Afzal
Assistant Professor of Physiology