The walls of blood vessels are composed of three layers (or tunics). The artery right has a thicker wall and a smaller Renal elastic artery. These post capillary veins then unite and form venules, which then progress to larger veins, which will return deoxygenated blood back to the heart. Definition of the human blood circulation , veins and their special features , direction of blood flow . Arteries. Basic Histology -- Artery and Vein. In this image you can see part of an artery (art) and corresponding vein. Arteries have thicker walls and tend to have narrower lumens. Can you identify which is the artery and which is the vein in this picture? There are two types of blood vessels in the circulatory system of the body: arteries that carry oxygenated blood from the heart to various parts of the body and veins that carry blood towards the heart for purification. Both arteries and veins have are composed of the same three layers. Basic Histology -- Artery and Vein. There are several clues you can use to figure out which is which. Description: This is a section through a comparable sized artery and vein. Please tell me that you've wondered at least once how this part of your insides looks like! Read more! Arteries have thicker walls and tend to have narrower lumens. The right superior pulmonary vein passes in front of and a tad below the pulmonary artery at the root of the lung, and the inferior pulmonary vein is situated at the lowest part of the lung hilum.In reference to the heart, the right pulmonary veins pass behind the right atrium and superior vena cava return, and the left pulmonary veins pass in front of the descending thoracic aorta. Do not consider oxygenation when classifying a vessel as an artery or vein. - 40X In many parts of the body, arteries and veins occur in pairs, one (the artery) taking blood to an organ and the other (the vein) returning it to the heart. The walls of arteries are thicker than that of veins to withstand pulsatile flow and higher blood pressures. Histology - Artery and vein View Related Images. At parturition the umbilical vein and urachus remain outside the abdomen. Both types of blood vessel have an inner lining of simple, flat cells called "endothelium". Note the much thicker tunica media of … You will often be able to distinguish arteries and veins, especally when they run together, as they usually do. until you release the first finger. relative lumen size decreases). Tunica intima/interna Tunica media Tunica adventitia. Description: This is a section through a comparable sized artery and vein. Answer: Elastic artery, muscular artery, arteriole, capillary, small venule, large venule, vein. Elastic Artery (Carotid Artery) - convey blood from the heart to systemic and pulmonary circulations. Histology - Artery and vein View Related Images. The thickness of the walls of the veins is much less, compared to the lumen, and the lumen is often collapsed as shown here. Magnified view of renal elastic artery of the kidney Artery inside adipose tissue.