The digestive system breaks down food and absorbs nutrients. It begins with the mouth and includes the esophagus, stomach, small intestine, large intestine and anus. Accessory organs like the liver, gallbladder and pancreas produce enzymes and bile to aid in chemical digestion. Food is mechanically and chemically broken down as it passes through the digestive tract, with the small intestine absorbing most nutrients and the large intestine absorbing water before waste is excreted through the anus.

1. DIGESTIVE SYSTEM
Mr. Sachin S.

2. INTRODUCTION
 The digestive system is responsible for
processing food, breaking down into usable
protein, carbohydrate, fats, mineral and other
substances.
 Digestive system starts from teeth and extended
till anus
 Food passes from mouth, esophagus, stomach,
small intestine, large intestine and eliminated
from anus
 Along the way through the digestive tract, the
pancreas, spleen, liver, gall bladder secrete
enzymes ( chemical substances ) which helps in
the digestion process

3. DIVISION OF DIGESTIVE SYSTEM
• Alimentary tube: tube from mouth to anus ( oral cavity, pharynx, oesophagus, stomach,
small intestine and large intestine
• Accessory organs of digestive system: teeth, tongue, salivary glands, liver, gall bladder
and pancreas.
• Mechanical breaking of food: physical breaking of food into small pieces
• Chemical digestion: breaking of food into complex chemical molecules that body can
utilized enzyme such as ( fat, protein and carbohydrates)

4. IMPORTANCE OF DIGESTIVE SYSTEM
• Breaking food into smaller molecules
• Carrying food for digestion.
• Storing food.
• Absorption of nutrients
• Excretion of waste.

5. ORGANS OF DIGESTIVE SYSTEM

6. Teeth
• The role of teeth is to break up food into
soft pulpy mass that can swallowed.
• This is the process that mechanically
breaks food into smaller pieces and
mixes it with saliva.
Tongue
• The tongue helps to move food between
the teeth.
• It also contains taste receptors.
• The slightly rough surface of tongue is
due to papilla that contain a maximum of
100 taste buds

7. SALIVARY GLANDS
• The salivary glands secretes saliva, as food chewed it is
mixed with the saliva secreted by three pairs of salivary
glands.
i. Parotid glands ( below ears )
ii. Submandibular ( submaxillary)
iii. Sublingual gland (bellow floor of mouth )
• Saliva is water made of blood plasma

8. OESOPHAGUS
• Oesophagus is muscle tube from pharynx to
the stomach.
• It passes the food downward even body
upside down
• Lower oesophageal sphincter which has flap
above stomach which doesn’t allow gastric
guise ( hydrochloric acid ) to come up.
• Dis functioning of lower oesophageal
sphincter leads to heartburn, which can also
affect lining of oesophagus.

9. STOMACH
• it is a sac, the stomach is a reservoir for
food, so that digestion proceeds gradually
and we do not have to eat constantly. Both
mechanical and chemical digestion take
place in the stomach.
• When the stomach is empty, the mucosa
appears wrinkled or folded. These folds
are called rugae
• pH is necessary to kill most of
microorganism enter in stomach

10. LIVER
• The liver consist of two large lobes right
and left
• It is just bellow diaphragm
• It contain to two major blood vessels
i. Hepatic artery ( carry oxygenated blood
)
ii. Portal vain ( carrying blood from
digestive organs and spleen)
• digestive function is the production of bile.

11. PANCREAS
• Size of pancreas is 6 inch (15 cm)
• They produce enzymes that are involved in the digestion of all three types
of complex food molecules.
• Carbohydrates, fat and protein.
• Secretion of pancreatic juice is stimulated by the hormones secretin.

12. SMALL INTESTINE
• Most absorption of the end products of digestion takes place in the small intestine.
• It is 6 M ( 20 feet ) long
• First 10 inch is duodenum of small intestine
• Digestion is completed in small intestine

13. LARGE INTESTINE
• The large intestine, also called the colon.
• It is approximately 2.5 inches (6.3 cm) in diameter
and 5 feet (1.5 m) in length.
• No digestion takes place in the colon.
• The functions of the colon are the absorption of water,
minerals, and vitamins and the elimination of
undigestible material.
• Bacteria present in large intestine is important part
of immune system.
• Waste is eliminated through anus.

14. MECHANISM
 The digestive system tract begin with mouth,
i. where the teeth and tongue with breaking of food, aided by saliva secreted by
salivary gland.
ii. The chewed food, combined with saliva, is swallowed, carrying it in the esophagus and
to stomach.
iii. In the stomach food combines with hydrochloric acid, bile and pancreatic juice which
further help in breaking down of food.
iv. when partially digested food passed through small intestine and large intestine.
v. Within intestinal canals, the nutrients are absorbed from chyme(thick partially
digested food )into blood stream and leaving the unusable residual.
vi. This residual passes through colon where most of the water is absorbed into blood
stream.
vii. The solid waste is compacted together and passes through anal canal and the anus.

15. THANK YOU