Question

Explain the working of human heart for class 7.

Answer 1

it is a muscular organ which pumps blood from the body of humans and even animals.the blood passes through blood vessels of the criculatory system.blood provided with oxygen and nutrients.
it is located between two lungs in the middle compartment in the body.the heart is divided into four chambers.

Answer 2

Heart is the muscular organ located in the chest cavity.It is slightly situated tilted towards left.
structure:
HuMan heart is divided into two halves.
each side of heart has two chamber.
The two upper chambers are called atria or auricles and two lower chambers are called ventricles.
There are valves between the auricles and the ventricle on each side.
The right auricle opens into the right ventricle and the left auricle into left ventricle.
There are no valves between two auricles or ventricles. As a result, the blood in the right side of heart remains completely separated from left side of heart.the valves allow blood to flow only in one direction and there is no mixing of oxygenated blood ( rich in oxygen) with deoxygenated blood.( rich in CO2).
Function:
The heart acts as pump and brings about movement of blood in the body.
All the atria and ventricles of the heart contract and relax at appropriate times and makes the heart behave like pump.since ventricles have to pump blood into various organs with high pressure they have thicker walls than atria.
Arteries , veins and capillaries are called as blood vessels.