Question

Explanation of inner circulatory system?

Answer 1

The heart and circulatory system (also called the cardiovascular system) make up the network that delivers blood to the body's tissues. With each heartbeat, blood is sent throughout our bodies, carrying oxygen and nutrients to all of our cells.
The circulatory system is composed of the heart and blood vessels, including arteries, veins, and capillaries. Our bodies have two circulatory systems: The pulmonary circulation is a short loop from the heart to the lungs and back again, and the systemic circulation which sends blood from the heart to all the other parts of our bodies and back again.

The heart has four chambers that are enclosed by thick, muscular walls. It lies between the lungs and just to the left of the middle of the chest cavity. The bottom part of the heart is divided into two chambers called the right and left ventricles, which pump blood out of the heart. A wall called the interventricular septum divides the ventricles.The upper part of the heart is made up of the other two chambers of the heart, called the right and left atria.The right and left atria receive the blood entering the heart. A wall called the interatrial septum divides the atria, and they're separated from the ventricles by the atrioventricular valves.
Systole: Contraction of cardiac muscles is called systole.
Diastole: Relaxation of cardiac muscles is called diastole.
Arteries: These are thick-walled blood vessels which carry oxygenated blood from the heart to different organs. Pulmonary arteries are exceptions because they carry deoxygenated blood from the heart to lungs; where oxygenation of blood takes place.
Veins: These are thin-walled blood vessels which carry deoxygenated blood from different organs to the heart. Pulmonary veins are exceptions because they carry oxygenated blood from lungs to the heart. Valves are present in veins to prevent backflow of blood.
Capillaries: These are the blood vessels which have single-celled walls.

Double Circulation: In the human heart, blood passes through the heart twice in one cardiac cycle. This type of circulation is called double circulation. One complete heartbeat in which all the chambers of the heart contract and relax once is called cardiac cycle.
Circulation of Blood through the heart:
$SystemicVein\Rightarrow SinusVenosus\Rightarrow RightAuricle\Rightarrow RightVentricle\Rightarrow PulmonaryArtery\Rightarrow Lungs\Rightarrow PulmonaryVein\Rightarrow LeftAuricle\Rightarrow LeftVentricle\Rightarrow Aorta\Rightarrow SystemicCirculation$