CBSE Class 7 Answered

The circulatory system is defined as the system which moves blood, oxygen, and nutrients through the body. An example of the circulatory system is the functioning of the human heart, blood and blood vessels. It consists of the heart, blood vessels i.e arteries, veins and capillaries, blood and lymph. Platelets are important to clot the blood at points of injury.

• The heart beats continuously and acts as a pump for the transport of blood which carries other substances with it.

• The heart is located in the chest cavity with its lower tip slightly tilted towards the left. The size of the heart varies from person to person; it is roughly the size of one’s fist.
• The human heart has four chambers. The two upper chambers are called atria and the two lower chambers are called ventricles. This partition between chambers helps to avoid mixing of oxygen-rich blood with carbon-dioxide-rich blood.