Blood supply of abdominal organs Flashcards
What are the main arteries that supply the abdomen?
- celiac trunk
- SMA
- IMA
What does the celiac trunk supply?
foregut = abdominal esophagus –> superior to major duodenal papilla
What does the SMA supply?
midgut = inferior to major duodenal papilla –> up to and including the proximal 2/3 transverse colon
What does the IMA supply’?
hindgut = distal 1/3 transverse colon –> midway through anal canal
What branches off the celiac trunk?
- left gastric A
- –esophageal branches
- splenic A
- –pancreatic branches
- –splenic branches
- –short gastric AA
- –left gastro-omental A
- common hepatic A
- –proper hepatic A
- ——left hepatic A
- ——right hepatic A
- ———-cystic A
- –gastroduodenal A
- —–supraduodenal A
- —–anterior and posterior superior pancreaticoduodenal A
- –right gastro-omental A
What branches from the SMA?
- anterior and posterior inferior pancreaticoduodenal AA
- jejunal and ileal AA
- arterial arcades
- vasa recta
- middle colic A
- right colic A
- ileocolic A
- colic, cecal, appendicular, ileal branches
- Marginal A
What branches off the IMA?
- left colic A
- sigmoid AA
- superior rectal A
Describe the arcades and vasa recta in the jejunum
arcades: large, fewer
vasa recta: long
Describe the arcades and vasa recta in the ileum
arcades: small, many
vasa recta: short
What is “Nutcracker Syndrome” aka renal vein entrapment?
- SMA passes anterior to left renal v and 3rd part of duodenum
- downward traction of SMA –> compression fo left renal v
- present with hematuria, proteinuria, left flank pain, N/V, left testicular pain in men
Describe the hepatic portal V
- covered by what?
- formed from?
- carries?
- contained in hepatoduodenal L
- formed by splenic v and SMA merging
- 1/3 cases IMV directly drains into HPV
- 2/3 cases IMV drains into splenic V (60%) or SMV (40%) - carries O2 poor blood and nutrients to liver
What are the porto-caval anastamoses? What do they appear as in portal HTN?
Esophageal varices
- portal: esophageal v from left gastric v
- caval: esophageal v from azygos v
Hemorrhoids
- portal: superior rectal v (continues as IMV)
- caval: inferior rectal v and middle rectal v
Caput medusae
- portal: para-umbilical vv
- caval: epigastric vv
Other
- portal: visceral vv (colic, splenic)
- caval: retroperitoneal vv of posterior abdominal wall and diaphragm
What is the blood supply of rectum above the pectinate line?
- derived from endoderm
- superior rectal a from IMA
- superior rectal v –> IMV –> portal system
What is the blood supply of the rectum below the pectinate line?
- derived from ectoderm
- inferior rectal a from internal pudendal a
- inferior rectal v –>internal pudendal v –> internal iliac v –> common iliac v –> IVC
Where does the aorta enter the aortic hiatus?
T12
Where does the aorta end?
L4 dividing into right and left common iliac arteries
Is the aorta intraperitoneal or retroperitoneal?
retroperitoneal
What are the variations of the right hepatic artery to portal vein?
91% right hepatic artery is anterior to hepatic portal vein
9% right hepatic artery is posterior to hepatic portal vein
What are the variations of arteries supplying the liver?
accessory or replaced right hepatic artery may originate from SMA
accessory or replaced left hepatic artery may originate from left gastric artery
What does the hepatic portal vein sustain? What about the hepatic artery?
hepatic portal vein: liver parenchyma
hepatic artery: non-parenchymal structures (intrahepatic bile ducts)
What is in the cystohepatic triangle of Calot?
- common hepatic duct
- cystic duct
- visceral surface of liver
If the SMA is occluded, how can the pancreas get blood?
celiac artery –> common hepatic A –> gastroduodenal A –> superior pancreaticoduodenal A
What are common variations in the SMA?
- common trunk for right and middle colic arteries
- common trunk for right and ileocolic arteries
- absent middle colic A replaced by a large branch from left colic
- absent right colic A
What is the superior rectal artery from?
IMA
What is the middle rectal artery from?
internal iliacs
What is the inferior rectal artery from?
internal pudendal
internal hemorrhoids
- visceral innervation
- not painful b/c above pectinate line
- prolapse of rectal mucosa that contains the normally dilated veins of the internal venous plexus
- bleeding is bright red due to the abundant ateriovenous anastamoses
external hemorrhoids
- somatic innervation
- painful b/c below pectinate line
- thromboses or blood clots in veins of the external venous plexus
- covered by skin
- painful because they are located below the pectinate line and are innervated by somatic sensory fibers (inferior anal nerves)
IVC
- begins anterior to L5
- 2.5 cm to the right of midline
- on the right side of the aorta
- passes through caval opening of diaphragm at T8
- longer than aorta
