Heart- the
involuntary pump .
The heart is a
muscular organ which pumps blood . the
heart is covered by a pericardial membrane . it is of a size a human fist and weighs about 360 gms. As
oxygen and the carbon dioxide both have
to transported by the blood , the heart
has different chambers , the left and the right , to prevent oxygen rich blood from mixing with the blood containing carbon dioxide . the left half
carries oxygenated blood . such separations allows a highly efficient supply
of oxygen to the body. This is very essential in the animals that have high energy needs
, such as bird and mammals , which
constantly use energy to maintain their
body temperature. Each half is further divided into two chambers the upper one
is called as atrium and the lower one is called ventricles therefore the human heart has four
chambers.
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