Digestive System Sudarshana Elapatha

National Dip. In Teaching

The digestive system serves for digestion of

complex food into

simpler end products which are capable of being absorbed.

Digestion

Process of

food gets shaped into

bolusby the action of

The

in

converts

starch sugar.in to

amylase enzyme

is capable of Antibacterial

Action

by the a virus which infects

the salivary

mumps is caused

glands

The disease

the oesophagus

through the pharynx.

The food bolus in the buccal cavity,

enters

The pharynx is common to both respiratory tract and alimentary canal.

Stomach

.

The oesophagusFood that enters

Cardiac sphincter

down toThe

The oesophagus

with the aid of

peristaltic contractions

Stomach

with an inner lining of longitudinal folds.

is a thick

Muscular sac Muscular sac

is formed when food in the stomach is ground for 3-4 hours.

StomachA semifluid paste called

Stomach wall

&HCl acid Pepsin Renin

secretes

on the

food

coagulate milk

Stomach

Renin

serves to

of children

in the

pepsin

Polypeptide

is formed as a result of

incomplete digestion of proteins

by

pepsinProte

ins Polypeptide

In theStomach

GastritisBurning sensation in

the stomach

Gastritis Burning sensation in the

stomach

condition can initiate from intake of

food

highly acidicoily or spicy

not taking meals

timeat proper&

anxiety

Gastritis Burning sensation

in the stomach smokingcertain drugs alcoholintake of contribute to

gastritis condition

Intestine

Small

Small intestine consists of

3parts namely

Duodenum

Jejunum

Ileum

Duodenum Pancreatic juice

And Bile is secreted

on to the food which enters the

secreted from the

Food is made

basicby the

BILE

liver

The pancreatic juice contains

3Enzymes

Amylase

Lipase Trypsin

Amylase

and similar enzymes

Formation of

fromGlucose

Carbohydrate by the action of

Lipase

Fats Fatty acids &are formed by the action of

onLipids

Trypsin

proteins.

are formed by the action of

on

Amino acids

Food is digested

further by the addition of

intestinal juices in the

jejunum

are simple products of food .

Glycerol Fatty acids

Amino acids Glucose

Absorption

of simple end products of food

take place mainly

in the small intestine.

Absorption

The ileum is modified

to absorb the digested

final food products.

finger like structures

called

The inner wall of the ileum bears

Villi

Villi provide

more surface area

to nutrients

to be absorbed.

The Villi encapsulate a network of

blood capillaries anda lymphaticvein

(lacteal).

Glucose and Amino acids

absorb into blood capillaries

fatty acids and glycerol

absorb into

lacteals

It is long in structure,Hence the chyme remains inside it for a longer period of timeVilli provide more surface area to nutrients to be absorbed.

Villi encapsulate a network of bloodcapillaries and a lymphatic vein.

Substances which are not absorbed

passes to the

large intestine.

All the required nutrients

except water are absorbed to the body

by the timethey pass to the large intestine.

water Is reabsorbedBy the large intestine.