Artery

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Artery med.jpg

Arteries are the blood vessels in the Cardiovascular System which carry oxygenated blood from the heart to the rest of the body, with the exception of the Pulmonary Artery, which carries deoxygenated blood from the heart to the lungs. There is around 160 major arteries in the human body, and the largest artery is called the Aorta. Arteries branch into arterioles.

Like all major blood vessels, arteries consist of a layer of endothelial cells, a layer of smooth muscle cells and a layer of collagen. However, arteries are distinguished from other blood vessels because their smooth muscle layer is comparatively thicker than in veins. This is so that the blood, which is pumped from the heart at higher pressure, won't lose the pressure as it reaches the capillaries and allowing for efficient material exchange in the tissues. The total wall thickness of arteries is around 1.0 mm and internal diameter of around 4.0 mm, with the exception of the Aorta, which has wall thickness of 2.0 mm and internal diameter of 25.0 mm[1].

An artery is a blood vessel which carries blood away from the heart. It is the largest of all types of blood vessel, with strong vascular walls, the strength of which is required to move blood to body tissues which require oxygen.

Aterioles are small branches of arteries, and control the blood which is sent to capillaries. These are an important part of the arterial system[2].

Structure

The outer layer of an artery is called the tunica adventitia, which comes into contact with surrounding organs in order to protect the artery from wear. The inner layer is called a tunica intima has a smooth epithelium so that friction is reduced which is caused by blood flowing through the artery. The tunica media is the thickest layer and contains smooth muscle for contraction, to allow blood to flow through the artery[3].

In the heart, there are two main arteries; the pulmonary artery and the aorta. The pulmonary artery carries deoxygenated blood to the lungs to become oxygenated (using haemoglobin) to bind oxygen.

The aorta is the largest artery in the body and rises from the left ventricle of the heart, carrying oxygenated blood which can then be used in respiration.

References

  1. McGrawHill LANGE "Cardiovascular Physiology" 7th Edition D. E. Mohrman, L. J. Heller chapter 1 "Overview of the cardiovascular system
  2. Guyton, A. and Hall, J. (2011) Textbook of Medical Physiology, 12th edition. Philadelphia: Saunders Elsevier
  3. Rowland, M. (1992) Biology. Surrey: Thomas Nelson and Sons Ltd.
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