Page 101 - Science Class 07

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Transportation in Human Beings
• Circulatory System in Human Beings
• Heart— The Pumping Sta on
• Role of Liver and Kidneys
• Blood Circula on
• Circulatory System in Other Animals
During lunch me, Naina’s mother served her
bi er gourd. Looking at which Naina frowned
and pushed the plate across the table. Her
mother shouted at her and asked her to eat it,
“But maa, my stomach just can’t digest this and
the transporta on just doesn’t occur in my
stomach. What’s the point?” Naina replied.
“Human body can digest any edible item and
this item can be transported easily in form of
blood and nutrients anywhere in our body,”
said her mother. Naina wondered how can our
body transport this food into our blood and
other parts of the body? Does this happen in
plants too?
Let us find out about transporta on in animals:
Like plants, human body also has a transpor-
ta on system which is also called the
circulatory system. But, the human circulatory
system is more complicated as compared to
the plants. Human body has a group of
complicated organs involved in circulatory
Science-7
and Animals
• Blood
• Blood Vessels
• Blood Transfusion
• Pulse Rate and Heart Beat
system. These organs con nuously work and
hence need more energy.
Circula on is the process by which nutrients,
respiratory gases and waste products are
transported through living organisms.
Like human beings, other unicellular and
mul cellular organisms also have a circulatory
system. But the process of circula on in
organisms varies from organism to organism. In
this chapter, you will study about the
circulatory system of human, amoeba, sponges,
earthworms, insects and other higher animals.
CIRCULATORY SYSTEM IN HUMAN BEINGS
In human beings, the various organs associated
with this system include the heart, lungs, blood
vessels, capillaries and blood. The heart is the
pumping organ that squirts out blood. The
heart does this with so much pressure that it is
capable of squir ng blood up to 9 meters high.
It never stops and beats con nuously so that
blood can travel to all parts of the body.
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