Where do portosystemic anastomoses occur?
A portocaval anastomosis or porto-systemic anastomosis is a specific type of anastomosis that occurs between the veins of the portal circulation and those of the systemic circulation.
Where are portosystemic shunts?
A portosystemic shunt (PSS) is an abnormal vein connecting the blood supply returning from the intestines to the vein returning blood to the heart, bypassing the liver (shunting). Portosystemic shunts can be either congenital (present at birth) or acquired.
What are included in the portal systemic anastomoses?
The major portal-systemic anastomoses include: 1) esophageal branches of left gastric vein with esophageal veins, 2) superior rectal vein with middle and inferior rectal veins, 3) paraumbilical veins with subcutaneous veins of anterior abdominal wall, 4) retroperitoneal veins with venous branches of veins of the colon …
What is anastomosis anatomy?
An anastomosis is a surgical connection between two structures. It usually means a connection that is created between tubular structures, such as blood vessels or loops of intestine. For example, when part of an intestine is surgically removed, the two remaining ends are sewn or stapled together (anastomosed).
Why does portosystemic anastomosis occur?
It is caused by blockage in the veins of the liver due to pathological conditions such as liver cirrhosis and the inability of the blood to flow through.
Why does portosystemic shunting occur?
Portosystemic shunt (PSS) is a common condition and usually follows portal hypertension or liver trauma, including iatrogenic injury [1–3]. However, congenital or spontaneous PSS can also occur and presents diagnostic along with management challenges [3].
What is the most common collateral pathway for the portal hepatic circulation?
Efferents from Umbilical Varices The most common path of drainage of paraumbilical veins is through the inferior epigastric veins, which follow the posterior face of the rectus abdominis muscles to finally reach the external iliac veins.
Where do arterial anastomoses occur in the body quizlet?
Where do arterial anastomoses occur in the body? There are other organs in which anastomoses occur—the brain, for example. The internal iliac arteries supply blood both to the pelvic organs and to the lower limbs. The pulse of the posterior tibial artery is palpated behind the knee.
Where does portal vein drain into?
the liver
The portal vein (PV) is the main vessel of the PVS, resulting from the confluence of the splenic and superior mesenteric veins, and drains directly into the liver, contributing to approximately 75% of its blood flow [1].
What is a portosystemic shunt in humans?
Portosystemic shunts (PSSs) are vascular anomalies that connect the portal circulation with the systemic circulation, diverting portal blood away from the liver.
How does portal hypertension cause portosystemic shunts?
Portal hypertension is a major complication which appears during CLD evolution. It is defined as an increase of portal blood pressure over 5-10 mmHg. Portosystemic shunts open when the venous portal-liver gradient becomes higher than 10-12 mmHg[5,6].
What are portosystemic varices?
Portosystemic collateral pathways (also called varices) develop spontaneously via dilatation of pre-existing anastomoses between the portal and systemic venous systems.
Where does the portal vein originate?
The portal vein (Fig. 23.11) originates at the junction of the splenic and superior mesenteric veins, which converge immediately posterior to the pancreatic neck. The portal vein courses obliquely toward the right to terminate at the porta hepatis, where it divides into right and left portal branches.
Which term refers to a circulatory route in which blood flows from an artery directly into a vein thereby bypassing the capillary?
lymphatic capillaries. Which term refers to a circulatory route in which blood flows from an artery directly into a vein, thereby bypassing the capillary? arteriovenous anastomosis.
Do veins have Vasa Vasorum?
Small blood vessels that supply the walls of larger arteries and veins are known as vasa vasorum. These blood vessels supply the outer wall (externa) of large arteries and veins.
What is porto-systemic anastomosis?
Porto-systemic anastomosis Portal caval system. A portocaval anastomosis is a specific type of anastomosis that occurs between the veins of the portal circulation and those of the systemic circulation .
Where is the anastomosis located?
Another anastomosis is between the ductus venosus (portal vein) and the inferior vena cava (systemic vein). This is very rare and at the site of patent ductus venosus.
What are the potential sites of portacaval anastomosis?
The inferior end of the esophagus and the superior part of the rectum are potential sites of a harmful portacaval anastomosis. In portal hypertension, as in the case of cirrhosis of the liver, the anastomoses become congested and form venous dilatations.
What is the anastomosis of the colonic vein?
The anastomosis between omental and colonic veins (portal veins) with the retroperitoneal veins (systemic veins) in the region of hepatic and splenic flexure. Another anastomosis is between the ductus venosus (portal vein) and the inferior vena cava (systemic vein).