Proper functioning of the circulatory system is very important as it helps in reaching all the nutrients and blood oxygen to every part of the body. There are lot of components and organs involved which complete the whole process of circulation. The process is disrupted when any of the related organs gets infected or damaged and functions partially or stops functioning completely.
The Human circulatory system is an organ system that is mainly concerned with transportation of nutrients, gases, blood cells and hormones throughout the body, through a network of blood vessels. It is also the main cooling as well as transportation system of the body. The RBCs carry nutrients and oxygen to the cells while the white blood cells in the circulatory system act as cleaners and start functioning whenever we are exposed to cold, infection or cut. The main components of circulatory systems are arteries and veins. Many times the veins consist of blood from which the oxygen and nutrients have been delivered already. These have low oxygen or no oxygen molecules and nutrients and are called deoxygenated blood. Such blood is very dark red in color. The regular blood looks bright red. Some veins specially carry oxygenated blood while there is one artery which only carries deoxygenated blood.
It consists of heart, blood and blood vessels. Blood vessels constitute arteries, veins, arterioles and capillaries. These play an important role in the functioning of cardiovascular or circulatory system. The structure of this system can be expressed as a closed loop that begins and also ends at one location- the heart. The heart is divided into left atrium, right atrium, left ventricle and right ventricle. The walls of the ventricle are stronger as well as thicker than the atria walls. The right atrium is placed uppermost and is that right chamber which accepts deoxygenated blood through the superior vena cava and inferior vena cava. The left atrium performs the function of collecting oxygenated blood present in the pulmonary veins and pumps it into the aorta which is the biggest heart artery from where it is distributed to arterioles and arteries.
The circulatory system can be divided into two categories depending upon the type of functioning.
The Systemic Circulation: It is a loop which beings from the heart and is connected to the different parts of body. The systemic circulation works exactly opposite to pulmonary circulation. During this circulation, the oxygen rich blood is collected by the arteries from the heart and is sent to various body tissues. During this process, the oxygen present in the blood is diffused inside the body cells and the carbon dioxide present in the cells is diffused back into the blood. The capillaries surrounding the body cells assist in this exchange of gases.
The Pulmonary Circulation: The pulmonary circulation is like a loop which runs from heart to the lungs. In this portion, deoxygenated blood received by the heart is transported to the lungs and the oxygenated blood is returned back to the heart. The deoxygenated blood leaves the right ventricle of heart via two pulmonary arteries and then flow into lungs. During respiration process in the blood carbon dioxide and oxygen are released by RBCs .This oxygenated blood is then transported back into the left atrium of heart via pulmonary veins. The systemic circulation then performs the function of distributing oxygen rich blood to various body parts.
The circulatory system also works with the help of other body systems. It works in coordination with respiratory system as well as digestive system to supply nutrients and oxygen to different body parts. The messenger chemicals or hormones present in the blood are secreted by the endocrine system. Hence the circulatory system also performs the function of circulating hormones for proper communication between the organs.