Page 19 - Science Class 07
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Small Intes ne Pancreas
The small intes ne is about 6 m long muscular The pancreas is a long, flat gland that lies in the
tube. The first slightly wider part of the small abdomen behind the stomach. It produces
intes ne is called duodenum. The rest, called enzymes that are released into the small
the ileum, is the longest part of the gut. The intes ne to help in diges on of food. It also
later stages of diges on take place in the small contains clusters of cells called islets. The cells
intes ne. The walls of the ileum produce in these islets produce hormones such as
intes nal juice and the diges ve processes of insulin and glucagon, which help to control the
the duodenum con nue for the me in the level of glucose (a type of sugar) in the blood.
ileum.
Bile is also emp ed into the small intes ne.
Nearly all the absorp on of digested food
Pancreas secrete insulin which maintains
materials takes place through the wall of the
the amount of sugar in our body. When
ileum through the villi. The villi (singular-villus)
pancreas of a person do not func on
are finger like outgrowths of the inner walls of
properly, he or she becomes diabe c.
the small intes ne.
Liver Large Intes ne
The liver is the largest gland in the body and is The undigested food passes through the large
situated on the right side of the upper intes ne. This undigested food contains a high
abdomen. It is reddish-brown in colour. It propor on of water. The walls of the large
secrete bile juice which is stored in a sac intes ne absorb much of this water, so it is not
located near the liver, called the gall bladder. lost from the body. The semi-solid remains are
When food reaches the small intes ne it called faeces. They are stored in the large
secretes bile juice into it. intes ne and passed out at intervals through
Bile juice helps in the diges on of food. Bile the anus. The large intes ne is muscular tube
juice, especially, breaks down the fat present in and is wider than small intes ne and its length
the food and converts it into smaller molecules is about 1.5 m and diameter is 4-6 cm.
to be digested easily.
Advancement in medical science has
enabled the doctors to transplant liver. In
transplanta on, unhealthy organ of the
body is replaced by healthy one which is
donated by another person.
Absorp on
The digested food is absorbed by the small
intes ne. The inner wall of the small intes ne
Liver has millions of minute finger like projec ons
Science-7 19
