What do medical smv.spv.pv mean respectively?

PV is portal vein, SMV is superior mesenteric vein and SPV is splenic vein.

1, portal vein:

The pressure on the blood vessel wall when the blood in the vein flows is called venous blood pressure. Venous pressure is very low, generally expressed by the height of water column.

The venous pressure in different parts is different. The closer to the heart, the lower the pressure. Venous pressure is influenced by many factors, such as the distance between vein and right atrium, posture, respiratory movement and muscle movement, which can increase or decrease venous pressure.

2.SMV is superior mesenteric vein.

Walking in the mesentery, accompanied by arteries of the same name. Venous blood is collected from the duodenum to the intestine, part of the stomach and pancreas above the left curvature of the colon, and forms a portal vein with the splenic vein.

3.SPV is a splenic vein

Splenic vein is one of the main branches of portal vein, which is mainly formed by the confluence of several veins of spleen. It generally runs behind the pancreas. It not only collects venous blood in the distribution area of splenic artery, but also receives the inflow of inferior mesenteric vein.

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Extended data:

Veins are mainly divided into:

1, venules:

Capillaries gradually turned into veins, and initially only a thin layer of connective tissue was added around the endothelium. When the diameter reaches 50μm, sparse smooth muscle appears between endothelium and connective tissue. When the diameter is large, the smooth muscle becomes a complete layer, and those with a diameter less than 500μm belong to venules. Veins with a diameter of 0.2 ~ 1 mm are called venules.

2. Intermediate vein:

The diameter of blood vessels is 1 ~ 10 mm, and the wall thickness is about110. In addition to the vein trunk, anatomically named visceral veins and veins at the distal extremities all belong to this category. The intima is thin, the endothelial cells are polygonal, and the endothelium is thin or not obvious, containing a small amount of collagen fibers, elastic fibers and fibroblasts. Most of them have no internal elastic membrane, but the blood vessels of lower limbs have thin internal elastic membrane.

3. Great veins:

Their diameters are all more than 9 ~ 10 mm, including external jugular vein, innominate vein, azygos vein, pulmonary vein, external iliac vein, renal vein, adrenal vein, superior mesenteric vein, splenic vein, portal vein and vena cava. The wall of great vein is thin, about 1/20 in diameter. The structure of intima is basically the same as that of middle vein. The subcutaneous tissue contains collagen fibers, elastic fibers and longitudinal smooth muscle bundles.