Artery

An artery carries blood away from the heart and into the body. Read more about structure, function and important diseases of the arteries here!

Artery

As artery is a blood vessel called, which leads the blood away from the heart into the body. Arteries, unlike veins, have a pronounced muscle layer in their walls. In them, the pulsation of the heartbeat is noticeable, which is why they are also called punch or pulsatile arteries. Read all important information about the arteries here!

Product Overview

artery

  • Venous versus arterial

  • Arteries: Structure

  • Various arteries at a glance

  • arterioles

  • Diseases of the arteries

Venous versus arterial

Arteries lead blood away from the heart, veins toward the heart. The proportion of the two types of vessels in the circulatory system is very different: Compared to the veins, which account for the major part of the blood vessels with around 75 percent, arteries are outnumbered by only about 20 percent (capillaries 5 percent). They are distributed throughout the body and usually found in the vicinity of the veins.

Venous blood is often equated with oxygenated blood and arterial oxygenated blood. But this is not correct: Although most arteries actually transport oxygen-rich and most veins oxygen-poor blood. The pulmonary arteries divert oxygen-poor blood from the heart to the lungs, where it absorbs new oxygen from the breathing air. The now oxygen-rich blood flows back to the heart via the pulmonary veins.

Arteries: Structure

The diameter of the arteries ranges from 20 microns (microns) in arterioles (the smallest arterial vessels) up to three centimeters in the aorta (the largest blood vessel in the body). The wall of all arteries consists of the classic three layers: Intima, Media, Adventitia.

Arteries generally have a thicker wall than veins because they have a higher pressure (100 to 75 mmHg versus less than 15 mmHg). The influence of internal pressure on the structure of the vascular wall becomes clear during vascular transplantation: When doctors place a piece of vein in the area of ​​an artery (for instance because of a narrowing of the blood vessels = stenosis in the leg), the wall changes and the vein gradually changes into an artery,

Characteristic of the wall of an artery is mainly the thick middle layer, which is hardly pronounced in the veins. The media contains smooth muscle and / or elastic connective tissue. The proportion of these two components varies, so that one can distinguish one elastic and one muscular type of arteries (in addition to transitional forms between the two):

Elastic-type arteries contain a particularly large number of elastic fibers in the media. Above all, the large vessels close to the heart belong to this type of vessel because they are particularly exposed to and must compensate for the high pressure fluctuations between contraction (systole) and relaxation (diastole) of the heart muscle. The wall of the muscular-type arteries, on the other hand, has a middle layer with much more smooth muscle. Such vessels are found predominantly in the organs. They can control the blood supply through the muscles in their walls.

There are four valves in the heart - the heart valves. Each of them can be faulty. See how the various heart valve defects arise and what consequences you have.

Various arteries at a glance

Important arteries in the body are:

  • Aorta (main artery)
  • Pulmonary Artery (Arteria pulmonalis)
  • Arm-head artery (brachiocephalic trunk)
  • Carotid Artery (Arteria carotis communis)
  • Collarbone artery (Arteria subclavia)
  • Liver-Spleen-Gastric Artery (Truncus celiacus)
  • Mesenteric artery (Arteria mesenterica)
  • Renal artery (Arteria renalis)
  • Pelvic artery (Arteria iliaca communis)
  • Upper Artery (Arteria brachialis)
  • Femoral artery (femoral artery)

Special arteries in terms of their shape or function are:

  • Barrier artery: can prevent the blood supply through muscle contraction in its wall (bronchi, penis, clitoris)
  • Tendril artery (Arteria helicina): strongly tortuous, can lengthen if necessary (in the penis during erection)
  • Collateral artery (Vas collaterale): secondary vessel of an artery; serves as an escape route (bypass or collateral circulation) in occlusion of this main artery
  • Endarteria: without collateral circulation

arterioles

In order to supply the entire body with sufficient oxygen, finer vessels are necessary. The arteries branch therefore into smaller vessels, the arterioles, which then split further into the capillaries. The capillary network then forms the transition to the venous system.

The vessel diameter of the arterioles varies between 20 to 100 micrometers (ΞΌm). The wall of the arterioles has less smooth muscle (thin media) and with 40 to 75 mmHg a slightly lower pressure than the larger arteries. In the white sclera of the eyes, these fine red vessels can be seen well.

Arterioli can contract and in this way slow the blood flow in the capillary bed. Thus, they have great influence on vascular resistance and blood pressure: both increase significantly as soon as the arterioles constrict. They are therefore among the resistance vessels. Threatens a large blood loss with life-threatening situation, contracting them and thus ensure the central blood flow and the supply of vital organs.

Diseases of the arteries

Arterial vascular diseases are usually occlusive diseases due to advanced arteriosclerosis: deposits and inflammation on the inner walls can narrow (stenosis) or even completely occlude a vessel and thus affect the oxygen supply (such as in a stroke or heart attack).

This can also happen because blood clots easily form on arteriosclerotically altered vessel walls, which can close a vessel in place (thrombosis) or - after being carried away by the bloodstream - elsewhere in the body (embolism).

Risk factors for arteriosclerosis and its sequelae include overweight, lack of exercise, high blood pressure, smoking and high blood lipid levels.

A pathological saccule or spindle-shaped enlargement of a artery is called aneurysm. It can suddenly break, which can become life-threatening (such as in the case of a rupture of the abdominal aorta).


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