Gi Anatomy, Usmle Step 1

Front 1

Where is the falciform ligament?
What structure does it contain, and what is this structure a derivative of?

Back 1

The falciform ligament divides the liver into R and L lobes, and it connects the liver to the anterior abdominal wall. It contains the ligamentum teres, which used to be the fetal umbilical vein.

Front 2

Where is the hepatoduodenal ligament, what structures does it contain, and what is its significance?

Back 2

Hepatoduodenal ligament connects the liver to the duodenum. It contains the portal triad - hepatic artery, portal vein, and bile duct. It's significance is that it can be compressed b/w the thumb and forefinger placed in the omental foramen (epiploic foramen of Winslow) to control bleeding. It connects the greater and lesser sacs.

Front 3

What is the gastrohepatic ligament, what does it contain, and what is its significance?

Back 3

The gastrohepatic ligament connects the liver to the lesser curvature of the stomach. It contains the gastric arteries, and it separates the R greater and lesser sacs. It can be cut during surgery to access the lesser sac.

Front 4

What is the gastrocolic ligament, what does it contain, and what is it a part of?

Back 4

the gastrocolic ligament connects the greater curvature of the stomach with the transverse colon. it contains the gastroepiploic arteries, and it is part of the greater omentum.

Front 5

What is the gastrosplenic ligament, what does it contain, and what does it separate?

Back 5

the gastrosplenic ligament connects the greater curvature of the stomach w/ the splene. it contains the short gastric arteries, and it separates the L greater and lesser sacs.

Front 6

What is the splenorenal ligament, and what does it contain?

Back 6

The splenorenal ligament connects the spleen to the posterior abdominal wall, and it contains the splenic artery and vein.

Front 7

What is the median umbilical fold, and what was it in fetal life?

Back 7

the medial umbilical fold is a single, midline ligament running from superior surface of bladder to umbilicus. also known as the urachus, was the allantoic duct in fetal life.

Front 8

What are the medial umbilical folds, and what were they in fetal life?

Back 8

the medial umbilical folds are bilateral ligaments running from vesicular branches of internal iliac arteries to the umbilicus. they used to be the fetal umbilical arteries.

Front 9

What are the lateral umbilical folds?

Back 9

lateral umbilical folds are bilateral, formed by inferior epigastric vessels, which fxn in adult life.

Front 10

What is the blood supply, parasympathetic innervation, and vertebral level of the foregut?
What structures are supplied?

Back 10

Celiac artery
Vagus nerve
T12/L1
Supplies: stomach, proximal duodenum, liver, gallbladder, pancreas

Front 11

What is the blood supply, parasympathetic innervation, and vertebral level of the midgut?
What structures are supplied?

Back 11

Superior mesenteric artery
Vagus nerve
L1.

Distal duodenum to proximal 2/3 of transverse colon

Front 12

What is the blood supply, parasympathetic innervation, and vertebral level of the hindgut?

Back 12

IMA
Pelvic nerve
L3

Distal 1/3 of transverse colon to upper portion of rectum; splenic flexure is watershed region.

Front 13

What are the three branches of the celiac trunk?
What does the L gastric artery supply?
What does the common hepatic artery supply?
What does the splenic artery suppy?

Back 13

L gastric, splenic, and common hepatic.

Left gastric artery supplies the lesser curvature of the stomach and the lower 1/3 of the esophagus.

The common hepatic artery gives off the gastroduodenal artery, then the right gastric artery. Eventually it splits into the L and R hepatic artery, the latter of which gives off the cystic artery. The gastroduodenal artery splits into the R gastroepiploic artery (which supplies the greatur curvature) and the superior pancreaticoduodenal artery. The R gastric artery supplies the lesser curvature (along w/ the L gastric artery).

The splenic artery is the largest branch of the celiac trunk, and passes posterior to the stomach to supply the spleen. It gives off short gastric arteries to the fundus of the stomach, and the L gastroepiploic artery (supplies the L half of the greater curvature and anastamoses w/ the R gastroepiploic).

Front 14

What arteries are in collateral circulation with the internal thoracic/mammary (subclavian)?

Back 14

Superior epigastric (internal thoracic) and inferior epigastric (external iliac)

Front 15

What artery is in collateral circulation with the superior pancreaticoduodenal artery (celiac trunk)?

Back 15

The inferior pancreaticoduodenal artery (SMA)

Front 16

What artery is in collateral circulation with the middle colic (SMA)?

Back 16

Left colic (IMA)

Front 17

What artery is in collateral circulation with the superior rectal (IMA)?

Back 17

Middle rectal (internal iliac)

Front 18

How does putting a shunt between the splenic and L renal veins relieve portal HTN?

Back 18

shunt blood into systemic circulation.

Front 19

What is the blood supply, innervation, venous drainage, and cancer risk above the pectinate line (upper 2/3 of rectum)?

Back 19

Above the pectinate line, the rectum drains to the internal iliac nodes, there is columnar epithelium, it is derived from endodrm, it is supplied by the superior rectal artery (branch of IMA) and it drains from superior rectal vein to IMV to portal system. It is supplied by the inferior hypogastric plexus (visceral innervation), so hemorrhoids are not painful. Risk of adenoCA.

Front 20

What is the blood supply, innervation, venous drainage, and cancer risk below the pectinate line?

Back 20

Drains to superficial inguinal nodes, has stratified squamous epithelium, is derived from ectoderm, is supplied by the inferior rectal artery, is drained by the inferior rectal vein --> pudendal vein --> internal iliac vein --> IVC. it's supplied by inferior rectal nerves (branch of pudendal nerve), so the external hemorrhoids are painful.
Risk of squamous cell carcinoma.

Front 21

Which surface (apical or basolateral) faces bile canaliculi and which faces sinusoids?

Back 21

The apical surface of hepatocytes faces the bile canaliculi, and the basolateral surface faces the sinusoids.

Front 22

What are zones I, II, and III?
Which is most affected by viral hepatitis?
Which is most affected by ischemia, alcoholic hepatitis, toxic injury, and has the P-450 system?

Back 22

Zone I is the periportal zone, and it is most affected by viral hepatitis.
Zone II is the intermediate zone.
Zone III is the centrilobar (pericentral vein) zone. Zone III (centrilobar/pericentral vein) has the P-450 system, is most affected by toxic injury and alcoholic hepatitis, and is first affected by ischemia.

SO THE ONLY THING THAT THE PERIPORTAL ZONE IS AFFECTED BY FIRST IS VIRAL HEPATITIS!!!

Front 23

What is the space of Disse?

Back 23

It is the perisinusoidal space, where the stellate cells (Ito cells) reside. It's also the space that's affected by fibrosis!