Cardiovascular apparatus. Also known as the cardiovascular system, it is the one that conducts blood and circulates it through the lymphatic system , leading the lymph in a unidirectional direction, towards the heart .
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- 1 Description
- 2 Unidirectional circulatory system
- 3 Pulmonary circulation
- 4 References
- 5 Sources
The heart acts as a pump that drives blood to the body’s organs, tissues, and cells . The blood supplies oxygen and nutrients to each cell and collects the carbon dioxide and waste substances produced by those cells.
Blood is transported from the heart to the rest of the body through a complex network of arteries , arterioles, and capillaries, and returns to the heart through venules and veins .
If all the vessels of this extensive network were united and placed in a straight line, they would cover a distance of 60,000 miles (more than 96,500 kilometers), enough to circle the World more than twice.
One-way circulatory system
The one-way circulatory system carries blood to all parts of the body. This movement of blood within the body is called circulation. The arteries carry oxygen-rich blood from the heart and the veins carry oxygen-poor blood to the heart.
In the pulmonary circulation, however, the roles are reversed. The pulmonary artery is the one that transports oxygen-poor blood to the lungs and the pulmonary vein is the one that transports oxygen-rich blood to the heart.
Twenty major arteries pass through the tissues of the body where they branch into smaller vessels called arterioles. The arterioles, in turn, branch into capillaries, which are the vessels responsible for supplying cells with oxygen and nutrients.
Most capillaries are thinner than a hair. Many of them are so thin that they only allow one blood cell to pass through at a time. After supplying oxygen and nutrients and collecting carbon dioxide and other waste substances, the capillaries lead the blood to wider vessels called venules. Venules join to form veins, which transport blood back to the heart to oxygenate it.