Question

Explain circulatory system through a diagram.

Answer 1

Hint: Human circulatory system is also defined as blood vascular system. This system is made up of a muscular chambered heart, a network of closed branching blood vessels namely arteries, veins and capillaries and blood, the fluid which is circulated. The circulatory pathways are of two types open and closed.

Complete answer: The heart that is the pumping organ of a human body is composed of four chambers, two atria and two ventricles. Double circulation is defined as the process in which blood passes through the heart twice for each circulation of the body. It includes two types of circulation namely pulmonary and systemic circulation.

Pulmonary Circulation:- The deoxygenated blood pumped into the pulmonary artery is passed on to the lungs from where the oxygenated blood is carried by the pulmonary veins into the left atrium. This pathway is known as pulmonary circulation.
Systemic Circulation
The oxygenated blood that enters the aorta is carried by a network of arteries, arterioles and capillaries to the tissues at which the deoxygenated blood is collected by a system of venues, veins and vena cava and now this blood emptied into the right atrium. This is called systemic circulation. T, the systemic circulation provides nutrients, oxygen and other essential substances that are advantageous to the tissues and takes $\mathop {CO}\nolimits_2 $, and other harmful substances away for elimination.
The systemic circulation is made up of small muscular arteries and arterioles and they offer a larger amount of resistance to blood flow than that in the pulmonary circulation. Even after having the differences in resistance, the rate of blood flow through the systemic circulation should always be matched to the flow rate of the pulmonary circulation. the amount of work performed by the left ventricle is mostly and usually greater than that performed by the right ventricle, so the musculature wall of the left ventricle is thicker than that of the right ventricle.

Note: The circulatory patterns are of two types open or closed. In open circulatory system, blood is pumped by the heart which passes with the help of large vessels into open spaces or body cavities. The body cavities are called sinuses. This type of system is possessed by the members present in arthropods and molluscs. In a closed circulatory system, the blood pumped by the heart is always circulated through a closed network of blood vessels. This system or pattern is considered to be more advantageous as the flow of fluid can be more precisely regulated.