Blood vessels of the abdomen and pelvis

Abdominal aorta

The abdominal aorta is a continuation of the thoracic aorta, once it has traversed the aortic hiatus of the diaphragm. As it supplies just about everything in the abdomen and pelvis, it is a large caliber artery, and is as wide as a garden hose (~25mm) and gives numerous branches.

The course of the abdominal aorta is quite simple. After passing through the aortic hiatus (T12), it descends slightly to the left of the lumbar vertebrae, with the inferior vena cava being just right to it. The aorta terminates at the L4 level by bifurcating into left and right common iliac arteries.

There are 10 major branches of the abdominal aorta. We can sort them by what part of the abdomen and pelvis they supply into visceral (organs), parietal (abdominal walls) and terminal branches. 

We’ve created a diagram with major branches of the abdominal aorta to ease up your straight recall practice.

Don’t get petrified if you have realized that the aorta has more branches than you initially anticipated. Once we break things down and look at the blood supply organ by organ, it will all sort nicely in the end.

If you still feel overwhelmed by so many branches of the aorta, check out these 4 steps to memorize anatomical terms which will make your study process a lot more efficient.

Inferior vena cava

The inferior vena cava (IVC) is the headmaster of the veins department. It collects all the blood from the abdomen, pelvis and lower limbs and carries it to the right atrium of the heart. The IVC is formed by merging of the left and right common iliac veins at the L5 vertebral level, just in front of the aortic bifurcation. 

The inferior vena cava then ascends to the right of the abdominal aorta along the vertebral column, receiving blood from numerous tributaries, and eventually passing through the caval foramen of the diaphragm. Notice that the veins draining the organs of gastrointestinal tract do not empty into the inferior vena cava. This is important to remember! Continue reading below to find out more about their venous drainage. 

Abdominal wall

Now that we understand the beginning (abdominal aorta), and the end (inferior vena cava) of the abdominopelvic circulation, let’s fill the gaps in between by looking the supply and drainage of the different parts of this region, beginning first with the abdominal wall. 

Stomach

The stomach is supplied by the branches of the celiac trunk, which include the right and left gastric, right and left gastro-omental, short gastric and posterior gastric arteries. Venous blood is conveyed by the right, left and short gastric, prepyloric, right and left gastro-omental veins. They all empty into the system of the hepatic portal vein.

Small and large intestines

The intestines have very rich blood supply. Put simply, they are supplied and drained by the branches of three primary vessels: the celiac, superior and inferior mesenteric vessels. Let’s take a closer look into that.

Vessels of the small intestine are grouped by which segment they supply: 

• The duodenum is supplied by the superior and inferior pancreaticoduodenal arteries, which are the branches of the gastroduodenal and superior mesenteric arteries, respectively. Venous drainage occurs via the prepyloric, superior pancreaticoduodenal and inferior pancreaticoduodenal veins, which are and drained by the superior mesenteric and hepatic portal vein. 
• The jejunum and ileum are supplied by the jejunal and ileal arteries, and drained by their venous counterparts, the jejunal and ileal veins (tributaries of the superior mesenteric vein).

The segmental approach to vasculature applies to the large intestine as well:

• The cecum is supplied by the ileocolic artery, and drained by the ileocolic vein. 
• The ascending colon is supplied by the ileocolic and right colic arteries (both branches of the superior mesenteric artery), and is drained by their venous counterparts, the ileocolic and right colic veins. 
• The proximal two-thirds of the transverse colon are supplied by the middle colic artery (of superior mesenteric artery) and while the distal third receives its arterial supply via left colic artery (of inferior mesenteric artery).  Both segments of the transverse colon are drained by the venous equivalents of the these arteries, which empty into the superior mesenteric and inferior mesenteric veins, respectively. 
• The descending and sigmoid colon are supplied by the left colic and sigmoid arteries, which are branches of the inferior mesenteric artery. Venous blood is drained via veins of the same name which empty into the  inferior mesenteric vein drains. 
• The rectum and anal canal recieve arterial blood from the superior, middle and inferior rectal arteries. The venous blood is conveyed through the superior, middle and inferior rectal veins.

Peritoneum

As you know, the peritoneum consists of the parietal and visceral peritoneum. The parietal peritoneum is supplied by the vessels of the abdominal wall. The visceral peritoneum is supplied by its associated viscera. So if we know that the intraperitoneal organs are the liver, spleen, stomach, superior part of the duodenum, jejunum, ileum, transverse colon, sigmoid colon and superior part of the rectum, we then know that their vessels supply the adjacent peritoneal formations.

Liver and gallbladder

Let’s see what supplies the liver, our detox center. The tissue of the liver is supplied by the hepatic artery, which is a branch of the celiac trunk. Interestingly, the blood delivered by the hepatic artery only represents one quarter of the total blood volume received by the liver. The other three quarters of the blood delivered to the liver come from the hepatic portal vein. Venous blood is drained by the hepatic veins, which empty into the inferior vena cava.

The biliary system, which consists of intra- and extrahepatic biliary ducts as well as the gallbladder, is supplied by several vessels:

• Intrahepatic biliary ducts are supplied by the branches of the hepatic artery, and drained by the hepatic veins. 
• The common bile duct is supplied by the cystic artery, right hepatic artery, superior pancreaticoduodenal and gastroduodenal arteries. The hepatic veins and superior pancreaticoduodenal vein drain the common bile duct.
• The gallbladder is supplied by the cystic artery, and drained by the cystic vein. 

Pancreas

The pancreas is supplied by the pancreatic branches of the splenic, gastroduodenal and superior mesenteric arteries (SMA). 

The splenic artery gives off several pancreatic branches which supply the body and tail of the pancreas. The gastroduodenal artery gives off the superior pancreaticoduodenal artery, whereas the superior mesenteric artery provides the inferior pancreaticoduodenal artery; these deliver arterial blood to the head of the pancreas. The pancreas is drained by the pancreatic and pancreaticoduodenal veins, which empty into the splenic, superior mesenteric and hepatic portal veins.

Kidneys

Kidneys are supplied by the renal arteries, which are bilateral branches of the abdominal aorta. The kidneys are drained by the renal veins, which are tributaries to the inferior vena cava.

Reproductive organs

Reproductive organs in both sexes are supplied by branches of the gonadal (testicular or ovarian) and internal iliac vessels.

Concerning the blood supply of the male pelvis, here are the must-know facts:

• The ductus deferens (formerly known as the vas deferens) is supplied by the superior vesical artery and drained by the testicular vein. 
• Seminal glands are supplied by the inferior vesical and middle rectal arteries, and drained by the middle rectal veins. 
• The prostate is supplied by the inferior vesical, internal pudendal and middle rectal arteries. It is drained by the prostatic venous plexus which empties into the internal iliac vein. 
• The testes are supplied by the testicular arteries, and drained by the pampiniform venous plexus. Testicular veins emerge from the plexus, with the right testicular vein emptying into the IVC, and the left into the left renal vein. 
• The penis is supplied by the branches of internal and external pudendal arteries, while it is drained by the deep dorsal vein of the penis, a tributary to the internal pudendal vein.

There are several facts you should remember about the female pelvis blood supply:

• The ovaries are supplied by the ovarian arteries, and drained by the pampiniform venous plexus which empties into the ovarian vein. Note that the right ovarian vein empties to the IVC, whereas the left empties into the left renal vein. 
• The uterus is supplied by the uterine arteries and drained by the uterine veins. 
• The vagina is supplied by the uterine, vaginal and internal pudendal arteries. It is drained by the vaginal venous plexus.