29 Visceral Vasculature

STUDYAIMS

At the end of your study, you should be able to

Know the unpaired branches of the abdominal aorta

Know the major branches of the celiac trunk, superior mesenteric artery, and inferior mesenteric artery

Know the unpaired branches of the abdominal aorta and their distribution of blood

Understand the two types of venous drainage from the abdomen

Describe the formation of the hepatic portal vein from the splenic and superior mesenteric veins

Know the tributaries of the splenic and superior mesenteric veins

Describe the lymphatic drainage of the abdomen

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GUIDE

Abdomen: Visceral Vasculature

Arterial supply: Unpaired branches of the abdominal aorta (Section 4-2: Abdomen-Body Wall)

[Plate 284, Arteries of Liver, Pancreas, Duodenum, and Spleen]

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[Plate 285, Celiac Arteriogram]

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[Plate 286, Arteries of Duodenum and Head of Pancreas]

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Celiac trunk

Arises at T12

Supplies

Lower one third of esophagus

Stomach

First and second parts of duodenum

Pancreas

Spleen

Liver

Biliarysystem

Branches

Left gastric artery

Common hepatic artery

Splenic artery

Left gastric artery

Supplies distal esophagus and lesser curvature of stomach

Anastomosis with right gastric artery

Splenic artery

Supplies bodyof pancreas and spleen directly

Branches:

a.Left gastroepiploic: supplies left side of greater curvature of stomach, anastomoses with right gastroepiploic

b.Short gastric arteries: supplyfundus of stomach

Common hepatic artery

Extends retroperitoneallyto the right to reach hepatoduodenal ligament

Divides into gastroduodenal and proper hepatic arteries

Gastroduodenal arterybranches:

a.Superior pancreaticoduodenal supplying the head of pancreas and proximal duodenum

b.Right gastroepiploic arterysupplying right side of greater curvature of stomach

Proper hepatic branches:

a. Right and left hepatic arteries to right and left lobes of liver

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b.Right gastric arteryto right portion of lesser curvature of stomach

c.Cystic arteryusually from the right hepatic artery supplies the gallbladder and cystic duct

Superior mesenteric artery(SMA)

Arises at L1

Supplies the gut from the second part of duodenum as far as the distal one third of the transverse colon

Major branches include:

Inferior pancreaticoduodenal

a.Supplies duodenum (distal to entryof bile duct), pancreas, and spleen

b.Anastomosis with superior pancreaticoduodenal

Jejunal and ileal branches

a.Form anastomotic loops (arterial arcades) Fewer large loops in jejunum

Manyshorter loops in ileum

b.Loops give off vasa recta (straight arteries) Longer in jejunum

Shorter in ileum

Ileocolic artery:

a.Supplies caecum and some of the ascending colon

b.Supplies appendixvia appendicular branch

Right colic artery: supplies ascending colon and proximal transverse colon

Middle colic artery: supplies proximal two thirds of transverse colon

Inferior mesenteric artery(IMA)

Arises at L3

Supplies distal one third of the transverse colon → proximal rectum

Branches include:

Left colic artery: supplies distal transverse, descending and sigmoid colon

Superior sigmoid artery(ies): supplies sigmoid colon

Superior rectal artery(terminal branch of inferior mesenteric): supplies proximal rectum

Median sacral artery

Arises from posterior aspect of aorta just above bifurcation

Descends to supplylower lumbar vertebrae, sacrum and coccyx

Arterial supply: Paired branches of the abdominal aorta

[Plate 283, Arteries of Stomach, Liver and Spleen]

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Inferior phrenic arteries

First branches of abdominal aorta (or from celiac trunk)

Supplyinferior surface of diaphragm

Give rise to sixto eight superior suprarenal arteries on either side Middle suprarenal arteries

One or more on either side

Originate from aorta near origin of celiac trunk Renal arteries

Arise at level of L1/L2 intervertebral disc

Right renal arterylonger and passes posterior to inferior vena cava (IVC)

Divide close to hilum into five segmental end arteries Gonadal arteries

Arise inferior to renal arteries but superior to inferior mesenteric

Mayarise at different levels on either side

Run anterior to ureters, cross origin of external iliac vessels in suspensoryligament of ovaryand enter broad ligament

Divide into ovarian and tubal branches to supplyovaryand uterine tube

Branches anastomose with correspondinglynamed branches of uterine artery Lumbar arteries

Usuallyfour pairs

Given off from posterior aspect of aorta

Each gives off a dorsal branch

Supplies musculature of back

Gives off a spinal branch to vertebral column and spinal roots

Rest of arterysupplies anterolateral abdominal wall Common iliac arteries

Formed bybifurcation of aorta at level of iliac crest (slightlybelow level of umbilicus)

Follow medial borders of psoas muscle to pelvic brim

Bifurcate into internal and external iliac arteries at pelvic brim Supplypelvic viscera and lower limb

Venous Drainage (Section 4-2: Abdomen-Body Wall)

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Veins draining the abdominal viscera are tributaries of one of two venous systems

Inferior vena cava

Portal vein

No vein equivalent to celiac trunk or gastroduodenal vein

Splenic vein and superior mesenteric vein unite to form the portal vein

Tributaries of the splenic vein

Inferior mesenteric vein and its tributaries (left colic, sigmoid, superior rectal)

Pancreatic veins

Left gastroepiploic vein

Short gastric veins

Tributaries of the superior mesenteric vein

Inferior pancreaticoduodenal vein

Right gastroepiploic vein

Right colic vein

Ileocolic vein

Jejunal veins

Ileal veins

Veins draining directlyinto portal vein

Cystic vein

Superior pancreaticoduodenal

Left and right gastric veins also may

Tributaries of the IVC

Common iliac veins

Lumbar veins

Enter IVC in irregular pattern

Second lumbar vein mayenter left renal vein

Anastomose with tributaries of epigastric veins

Are connected to each other on either side bya vertical anastomotic channel, the ascending lumbar vein

Ascending lumbar veins connect with azygos vein on the right and hemiazygos vein on the left

Right gonadal vein (left drains to left renal vein)

Right and left renal veins

Right suprarenal vein (left drains to left renal vein)

Right inferior phrenic vein (left drains to left renal vein)

Hepatic veins

Two to three in number

Emptyinto IVC just below diaphragm

Blood from the hepatic portal vein constitutes approximately70% of the liver's blood supply

Lymphatic Drainage (Section 4-2: Abdomen-Body Wall and Section 4-4: Abdomen-Viscera (Gut) and 4-5: Abdomen-Viscera (Accessory Organs) for specific organs)

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Lymphatics generallyfollow arteries

Drain to local, then regional lymph nodes (lumbar, celiac, superior, and inferior mesenteric nodes)

Main lymphatic ducts of abdomen from regional nodes

Intestinal lymphatic trunks (single or multiple)

Right and left lumbar lymphatic trunks

Thoracic duct

Begins with union of main lymphatic ducts of abdomen, unless cisterna chili is present

Ascends into thoracic through aortic hiatus in diaphragm

Cisterna chili

Thin walled sac or dilation at union of main lymphatic ducts of abdomen

Drains to thoracic duct

If present, occurs at the level of L1/2

Not seen in all individuals

Can varyin size and shape

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