List of Partners vendors. The circulatory system, also known as the cardiovascular system, is a simple loop which starts, and ends, with your heart. It is a closed system, meaning blood does not enter or leave the system during its journey from your heart to your body and back again. In such a system, a continuous flow of the same liquid can be pumped through the loop again and again.
Your blood is vital to your well-being and circulates nutrients including electrolytes, oxygen, carbon dioxide and amino acids throughout your body. Your heart is responsible for the majority of the circulatory system's function and is where the process begins. The circulatory system begins in your right atrium, the upper right-hand chamber of your heart. Blood moves from the right side of your heart through your lungs to get rid of carbon dioxide and pick up oxygen, and then returns to the left side of your heart, ending up in the left ventricle.
The left ventricle is the strongest part of the heart, since it must pump blood out to the rest of the body. When it comes to circulating blood throughout your body, the left ventricle is the most important chamber in the heart.
The left ventricle is the largest of the four chambers and is responsible for generating the force necessary to propel your blood out of your aorta, the first artery your blood enters as it leaves your heart. Your blood travels from your aorta through a series of smaller blood vessels until it reaches your capillaries.
Before reaching your capillaries, however, blood must travel through the arterioles, where its speed and pressure are constantly adjusted as different segments of the arterioles change diameter in response to pressure and chemical sensors positioned nearby. These sensors adjust blood flow via the arterioles in response to changing conditions in your body.
Because of arteriole action, by the time your blood reaches your capillaries, it is no longer traveling in a pulsing fashion.
Blood flows continuously through the capillaries, it does not "squirt" and "pause" as your heart beats. This continuous flow is necessary because there is a constant exchange of oxygen and nutrients happening in the capillary walls. No cell in the body is far from a capillary. As blood travels through the capillaries, its supply of oxygen is reduced and has picked up waste products as well. Arteries divide like tree branches until they are slender.
The largest artery is the aorta, which connects to the heart and picks up oxygenated blood from the left ventricle. The only artery that picks up deoxygenated blood is the pulmonary artery, which runs between the heart and lungs. Capillaries The arteries eventually divide down into the smallest blood vessel, the capillary. Capillaries are so small that blood cells can only move through them one at a time.
Oxygen and food nutrients pass from these capillaries to the cells. Capillaries are also connected to veins, so wastes from the cells can be transferred to the blood. Veins Veins have one-way valves instead of muscles, to stop blood from running back the wrong way. Generally, veins carry deoxygenated blood from the body to the heart, where it can be sent to the lungs. The exception is the network of pulmonary veins, which take oxygenated blood from the lungs to the heart.
Blood pressure Blood pressure refers to the amount of pressure inside the circulatory system as the blood is pumped around. Common problems Some common problems of the circulatory system include: Aneurysm — a weak spot in the wall of an artery Atherosclerosis — a narrowing of the arteries caused by plaque deposits Heart disease — lack of blood supply to the heart because of narrowed arteries High blood pressure — can be caused by obesity among other things Varicose veins — problems with the valves that stop blood from running backwards.
Where to get help Your doctor In an emergency, always call triple zero Things to remember The circulatory system delivers oxygen and nutrients to cells and takes away wastes. The heart pumps oxygenated and deoxygenated blood on different sides. The types of blood vessels include arteries, capillaries and veins. Lloyd, M. Give feedback about this page. Was this page helpful? Yes No. It is in the microscopic capillaries that blood performs its ultimate transport function.
Nutrients and other essential materials pass from capillary blood into fluids surrounding the cells as waste products are removed. Numerous control mechanisms help to regulate and integrate the diverse functions and component parts of the cardiovascular system in order to supply blood to specific body areas according to need.
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