anatomy 3 - Portosystemic anastomoses-Pectinate (dentate) line Liver anatomy-Biliary structures- Flashcards
Name three clinical signs of portal hypertension, detectable on physical exam.
Esophageal varices, anorectal varices, and caput medusae (gut, butt, and caput)
A patient with portal hypertension has rectal bleeding from prolapsed, dilated veins around the anus. How did this result?
Portosystemic anastomoses between the superior and middle rectal arteries created anorectal varices (not internal hemorrhoids)
What clinical finding results from portosystemic anastomoses when it involves the inferior epigastric and superior epigastric veins?
Caput medusae in the abdomen
An alcoholic patient has refractory gastrointestinal bleeding secondary to cirrhosis. What surgical procedure can be used to stabilize him?
Transjugular intrahepatic portosystemic shunt (TIPS) moves blood from the portal to hepatic veins, shunting blood to systemic circulation
Trace the blood flow from the anus to the IVC
Superior rectal vein to middle inferior rectal vein to IVC
Trace the blood flow from the esophagus to the IVC.
Left gastric vein to esophageal veins to azygos vein to IVC
Trace the blood flow from the umbilicus to the IVC.
Paraumbilical vein to epigastric vein to IVC
The pectinate line is formed where the embryonic ____ derivatives meet the ____.
Endoderm (hindgut), ectoderm
What type of hemorrhoids occur above the pectinate line? Below the pectinate line?
Internal; external
A patient presents with pain on defecation. You find that he has somatically innervated swollen masses on exam. What nerve innervates them?
Innervated by somatic nerves (the pudendal nerve) (these are external hemorrhoids) and thus are painful (internal hemorrhoids are not)
A patient is diagnosed with cancer occurring above the pectinate line. What kind is it? What if it were below the pectinate line?
Adenocarcinoma (endodermal derivation); squamous cell carcinoma (ectodermal derivation)
Above the pectinate line, lymphatic drainage is to what nodes?
Deep nodes
Below the pectinate line, lymphatic drainage is to what nodes?
Superficial inguinal nodes
Above the pectinate line, the blood supply comes from what artery?
The superior rectal artery (branch of the inferior mesenteric artery)
The superior rectal artery is a branch of what artery that comes off the aorta?
The inferior mesenteric artery
Innervation below the pectinate line is somatic or visceral?
Somatic innervation (hemorrhoids there are painful)
Below the pectinate line, the arterial supply is from what artery?
The inferior rectal artery
A 52-year-old man has rectal bleeding and a painful mass that flares up during defecation. Which nerve is involved?
Inferior rectal branch of the pudendal nerve (this is most likely an external hemorrhoid, which received somatic innervation)
A patient has a tear in the anal mucosa below the pectinate line. What is this called? Where is it most likely found on the anus?
Anal fissure; Posteriorly (below Pectinate line, Pain on Pooping, blood on Paper; located Posteriorly where it is Poorly Perfused
A patient with cirrhosis has internal hemorrhoids. Describe the pathway for venous drainage to the portal system, which is likely impaired.
Superior rectal vein to inferior mesenteric vein to portal system
The ____ surface of hepatocytes faces the canaliculi, whereas the ____ surface faces the sinusoids
Apical; basolateral
• In a patient with viral hepatitis, what zone of the liver is first affected?
Zone I, the periportal zone
A patient suffers septic shock and becomes hypotensive. Which zone of the liver is first to suffer necrosis?
Zone III, the pericentral vein zone, which is a watershed area
Drugs metabolized by the P-450 system are most likely to be found in which zone of the liver?
Zone III
