IMMUNOLOGY

Detailed explanation-1: -Blood, the heart and the vessels through which blood is pumped around the body, together make up the cardiovascular system.

Detailed explanation-2: -Blood comes into the right atrium from the body, moves into the right ventricle and is pushed into the pulmonary arteries in the lungs. After picking up oxygen, the blood travels back to the heart through the pulmonary veins into the left atrium, to the left ventricle and out to the body’s tissues through the aorta.