Blood circulation is essential for a healthy body. Every cell in the body needs to received oxygen and nutrients. Blood rich in oxygen is sent to the body organs, tissues and cells to nourish them, and the waste products that result are disposed of through the same system. The heart, lungs and blood vessels work together to complete circulation. The two major pathways are cardiopulmonary and systemic circulation. The three specialized routes are coronary, portal and fetal circulation. The body cannot function well without a strong circulatory system.
Blood circulates from the heart to the lungs and back to the heart in cardiopulmonary circulation. The blood that has picked up carbon dioxide and other waste products is brought to the right side of the heart where it is pumped through to the lungs. In the lungs, the carbon dioxide will be expelled from the body and the blood will obtain oxygen needed by the cells of the body. The now oxygenated blood will enter the left side of the heart. This is the efficient way the body has of maintaining the proper amount of oxygen and eliminating waste in the blood supply.
The left side of the heart pumps the oxygenated blood to the body tissues. The blood travels through the aorta to all the body tissues and organs, carrying much needed oxygen with it. The cells use this oxygen to function and also produce waste products such as carbon dioxide, which they need to remove. The blood that dropped off the oxygen is now able to pick up the waste products and carry them away from the cells and back to the heart to be sent to the lungs and expelled. This circulatory route is absolutely vital because it is the way body tissues receive oxygen and eliminate waste.
The body includes three specialized circulatory routes. Coronary circulation brings blood from the heart to the muscular layer of the heart wall. This gives the muscles the oxygen necessary to be able to pump the blood. It also carries away the carbon dioxide waste. Portal circulation takes blood from the digestive system and brings it to the liver. This helps the body keep its glucose concentration in the correct range. Fetal circulation is the route by which a fetus receives oxygen and nutrition from the mother's bloodstream and only occurs in pregnant women.
Circulation is affected by aging. As the body ages, the arteries lose some of their elasticity and become less pliable and smaller. This causes the heart to work harder to push the blood through the arteries to the body, resulting in decreased blood flow to the organs such as the brain, as well as an increase in blood pressure. Veins also suffer some changes that weaken the walls and valves of the vessels, making older people more prone to varicose veins. The smooth inner lining of all blood vessels becomes a bit rough as the body ages, leaving a body more prone to blood clots or thromboses.
The circulatory system includes several common disorders.
Aneurysm is when the wall of the artery thins a bit and allows blood to balloon in the area. This most often occurs in an artery and can be quite dangerous. Aneurysms are possible in veins as well.
Embolism is a blood clot that is able to travel. This is dangerous because it could travel to the brain, lungs or heart.
Arteriosclerosis is the thickening of the artery walls due to the loss of elasticity.
Atherosclerosis is when fatty deposits form along the arteries and block the blood flow.
Phlebitis is when the lining of a vein becomes inflamed and blood clots in the area. This leads to pain and swelling in the affected area.
Gangrene occurs if there is not a sufficient blood supply to an area, leading to tissue death.
- The Human Body in Health and Illness; Barbara Herlihy, PhD, RN; 2003
- Body Structures & Functions; Ann Senisi Scott; 2004