Hepatobiliary and Foregut

Question 1

How are the regions of the gut (foregut, midgut, hindgut) defined? What organs are in the foregut? (6) What is their blood supply?

Answer 1

Defined by blood supply.

Esophagus, stomach, liver, gall bladder, pancreas, spleen.

Foregut organs are supplied by the celiac trunk.

Question 2

Define mesentery, ligament, and omentum.

Answer 2

Mesentery: double layer of peritoneum between the body wall and an organ.

Ligament: double layer of peritoneum between organs or between an organ and the abdominal wall.

Omentum is a double layer of peritoneum between the stomach and another organ.

Question 3

What is a retroperitoneal organ? What is the difference between primary and secondary retroperitoneal organs?

Answer 3

Organs that are anchored to the posterior abdominal wall by CT (adventitia). They are behind the peritoneum and their anterior surface is covered by visceral peritoneum (serosa) that is continuous with the parietal peritoneum.

Primary = the organ developed on the posterior abdominal wall

Secondary = the organ developed outside the body and moved to the posterior abdominal wall, where it fused.

Question 4

Name two organs that are secondary retroperitoneal organs

Answer 4

Colon (ascending and descending parts), duodenum

Question 5

Superior to the diaphragm, the esophagus is surrounded by __________ and inferior to the diaphragm it is surrounded by ________.

Answer 5

superior: adventitia
inferior: serosa

Question 6

The ______ ______ of the diaphragm loops back on itself to form the esophageal hiatus at the spinal level of _____. Fibers from the right crus contribute to the formation of the _________ ________ _________, which prevents regurgitation of chyme into the esophagus.

Answer 6

right crus, level of T10. Contributes to the formation of the lower esophageal sphincter

Question 7

What type of muscle is the esophagus made out of?

Answer 7

Upper: skeletal
Middle: mixed skeletal and smooth
Lower: smooth

Question 8

What is the zigzag line of the esophagus?

Answer 8

Where SSNKE turns into columnar gastric epithelia.

Question 9

Weakening of the lower esophageal sphincter often causes ______.

Answer 9

GERD

Question 10

What are three complications of GERD?

Answer 10

1. Esophagitis
2. Strictures of the esophagus
3. Barrett’s esophagus (metaplasia)

Question 11

Describe the two hiatal hernias, including complications. Which one is more common?

Answer 11

Sliding hernia (common) is when the cardiac region of the stomach pushes up through the hiatus, moving the Z line superiorly. GERD almost always happens after this because the R. crus is weakened and the circular esophageal muscle is no longer in the same axial plane.

Paraesophageal hernia is when the Z line remains in place but a portion of the fundus balloons up through the hiatus, which can be constricted and become necrotic (bad).

Question 12

Describe the arterial blood supply to the lesser curvature of the stomach.

Answer 12

aorta –> celiac trunk

celiac trunk gives off left gastric artery to supply the superior part of the lesser curvature of the stomach

the celiac trunk turns into the common hepatic a. –> hepatic a. proper –> gives off the right gastric artery that supplies the inferior part of the lesser curvature of the stomach

Question 13

Describe the arterial blood supply to the greater curvature of the stomach.

Answer 13

At the same place where the common hepatic turns into the proper artery, there is a branch called the gastroduodenal artery that runs behind and under the small intestine and emerges anteroinferiorly to the greater curvature of the stomach as the right gastroepiploic a., which anastomoses with the left gastroepiplioc a. (from the splenic artery)

Question 14

Where along the duodenum do the outgrowths for the pancreas and liver occur initially during development?

Answer 14

The major duodenal papilla (Vater) - that’s why the duct is common!

Question 15

The sphincter of Oddi is mainly under _______ control.

Answer 15

hormonal (CCK)

Question 16

The liver is suspended from the _____ and _______ by _________.

Answer 16

suspended from the IVC and diaphragm by adventitia.

Question 17

What covers the liver (besides the bare area)?

Answer 17

Visceral peritoneum

Question 18

The lesser omentum forms the roof of the _______ ______ and is divided into two sections (ligaments). Name them.

Answer 18

it forms the roof of the lesser sac.

superior part is called the hepatogastric ligament (b/c it connects the stomach to the liver)

inferior part is called the hepatoduodenal ligament (b/c it connects the duodenum to the liver)

Question 19

What is in the portal triad? What are these structures found in?

Answer 19

portal vein, hepatic artery, common bile duct, all found within the hepatoduodenal ligament

Question 20

Fluids that have accumulated in the lesser sac can flow out and into the _______ ________ when a person lays on their right side.

Answer 20

hepatorenal recess (pouch of Morrison)

Question 21

The umbilical vein runs along the inferior part of the ________ ligament, and turns into the _______ ________ _______ after birth. The ductus venosus, which shunts blood from the _______ vein directly to the _____, turns into the _______ ________ after birth.

Answer 21

falciform ligament

the umbilical vein turns into the ligamentum teres hepatis (round ligament of the liver) after birth

the ductus venosus shunts blood from the umbilical vein to the IVC and turns into the ligamentum venosum after birth

Question 22

The liver gets 75% of its blood from the _______ _______ and 25% from the ______ _______.

Answer 22

75% from the portal vein and 25% from the hepatic arteries

Question 23

How many morphological lobes of the liver are there? How many functional segments are there?

Answer 23

4 morphological, 8 functional segments

Question 24

True or false: despite the size difference between the right and left liver lobes, blood supply is split roughly 50/50.

Answer 24

true

Question 25

What portions of the liver do the left and right hepatic arteries supply, respectively?

Answer 25

Left hepatic artery: left lobe, quadrate lobe, 1/2 of the caudate lobe

Right hepatic artery: right lobe, 1/2 of the caudate lobe (and also the gallbladder)

Question 26

As much as ___% of donor liver can be removed without complications; regrowth to original size occurs within a few weeks.

Answer 26

70%

Question 27

Name four venous systems that can become distended as a result from portal hypertension.

Answer 27

1. Esophageal veins (esophageal varices)
2. Retroperitoneal veins (colonic varices)
3. Rectal veins (hemorrhoids)
4. Paraumbilical veins (caput medusa)

Question 28

What do the spiral valves in the cystic duct (of the gallbladder) do?

Answer 28

They keep the duct open so that bile can flow into the gallbladder when the sphincter of Oddi is closed (not eating).

Question 29

What complications can occur in the following situations:

gallstones stuck in the cystic duct

gallstones stuck in the common bile duct

gallstones stuck in the hepatopancreatic ampulla

Answer 29

gallstones stuck in the cystic duct can cause cholecystitis

gallstones stuck in the common bile duct can cause cholecystitis and jaundice

gallstones stuck in the hepatopancreatic ampulla can cause cholecystitis, jaundice, and pancreatitis

Question 30

What is a cholecystoenteric fistula?

Answer 30

When a gallstone causes fusion of the transverse colon and gallbladder. The stone can drop into the colon and get stuck at the iliocecal sphincter.

Question 31

What supplies sympathetic autonomic input to the hepatobiliary system? Where do these synapse?

Answer 31

The greater splanchnic nerves (T5-9). They synapse at the celiac ganglion.

Question 32

Where would visceral pain of the hepatobiliary system be referred to? What about pain from the upper surface of the liver?

Answer 32

From hepatobiliary –> T5-9 dermatome (below nipples to just above the umbilicus - front and back).

From upper surface of liver –> phrenic (C3-5) - suprascapular and axillary nerves - shoulders

Question 33

What supplies parasympathetic input to the hepatobiliary system? What does their stimulation do?

Answer 33

Vagus nerve - stimulates bile production and glycogen synthesis

Question 34

Do hormones control most functions of the hepatobiliary system (instead of nervous input)? What do the hormones stimulate?

Answer 34

Yeah, hormones stimulate gallblader contraction (CCK) and increase bile flow (secretin)

Question 35

Do transplanted livers have innervation?

Answer 35

Nope

Question 36

At what spinal levels do the vena cava, esophagus, and aorta pass through the diaphragm?

Answer 36

IVC: T8
Esophagus: T10
Aorta: T12

Question 37

The right and left gastro-epiploic arteries run within the ______ ________.

Answer 37

greater omentum