Search results
Results From The WOW.Com Content Network
There are three sizes of veins: large, medium, and small. Smaller veins are called venules, and the smallest the post-capillary venules are microscopic that make up the veins of the microcirculation. [2] Veins are often closer to the skin than arteries. Veins have less smooth muscle and connective tissue and wider internal diameters than ...
Venules; Veins. Large collecting vessels, such as the subclavian vein, the jugular vein, the renal vein and the iliac vein. Venae cavae (the two largest veins, carry blood into the heart). Sinusoids. Extremely small vessels located within bone marrow, the spleen and the liver.
Post-capillary venules are the smallest of the veins with a diameter of between 10 and 30 micrometres (μm). When the post-capillary venules increase in diameter to 50μm they can incorporate smooth muscle and are known as muscular venules. [1] Veins contain approximately 70% of total blood volume, while about 25% is contained in the venules. [2]
Capillaries merge into venules, which merge into veins. [22] The venous system feeds into the two major veins: the superior vena cava – which mainly drains tissues above the heart – and the inferior vena cava – which mainly drains tissues below the heart. These two large veins empty into the right atrium of the heart. [23]
In anatomy, the venae cavae (/ ˈ v iː n i ˈ k eɪ v i /; [1] sg.: vena cava / ˈ v iː n ə ˈ k eɪ v ə /; from Latin 'hollow veins') [2] are two large veins (great vessels) that return deoxygenated blood from the body into the heart. In humans they are the superior vena cava and the inferior vena cava, and both empty into the right atrium ...
A list of veins in the human body: Veins of the heart. Coronary sinus. Great cardiac vein; Oblique vein of left atrium; Middle cardiac vein; Small cardiac vein
Vasa vasorum are more frequent in veins than arteries. [2] Some authorities hypothesize that the vasa vasorum would be more abundant in large veins, as partial oxygen pressure and osmotic pressure is lower in veins. This would lead to more vasa vasorum needed to supply the vessels sufficiently.
In 1653, he wrote, "...the blood doth enter into every member through the arteries, and does return by the veins, and that the veins are the vessels and ways by which the blood is returned to the heart itself; and that the blood in the members and extremities does pass from the arteries into the veins (either mediately by an anastomosis, or ...