Hindgut - Anatomy

Question 1

What supplies the blood to the hindgut?

Answer 1

IMA

Question 2

Is the abdominal aorta intra or retroperitoneal?

Answer 2

Retroperitoneal (lying on posterior wall)

Question 3

What does the right colic artery supply?

Answer 3

Ascending colon and hepatic flexure

Question 4

What does the middle colic artery supply?

Answer 4

Some of hepatic flexure, proximal 2/3 of transverse colon

Question 5

Where is the SMV? Where does it always sit?

Answer 5

Always to the right of the SMA (and by right I mean left when looking at it)

Question 6

What is the function of the SMV?

Answer 6

Drains structures of the midgut

Question 7

What is the ascending part of the duodenum held in place by?

Answer 7

Small peritoneal ligament –> ligament of treitz

Question 8

Where does the SMA and SMV emerge?

Answer 8

Around L1, deep to neck of pancreas (trans-pyloric plane)

Question 9

What is the falciform ligament a remnant of?

Answer 9

Ventral mesentery

Question 10

What is the remnant of the umbilical vein?

Answer 10

Round ligament of the liver

Question 11

Where does the oesophagus pass through the diaphragm?

Answer 11

T10

Question 12

Where does the thoracic aorta pass through the diaphragm?

Answer 12

T12

Question 13

Where does the vena cava pas through the diaphragm?

Answer 13

T8

Question 14

What is found at the inferior aspect of the falciform ligament?

Answer 14

Thickened structure –> ligamentum teres

Question 15

As the falciform ligament progresses towards the diaphragm, what does it split into?

Answer 15

Right and left coronary segments which leave liver and attach to inferior surface of diaphragm

Peritoneum also reflects off the posterior surface

Question 16

If you slide your hand just inferior to the diaphragm in the sub-phrenic recess, why can your hand not go all the way around the liver?

Answer 16

Due to coronary ligaments reflecting off liver and attaching to diaphragm

Question 17

What are the 4 anatomical lobes of the liver? What do you need to look at to appreciate these lobes?

Answer 17

Look at the visceral surface:

• Right lobe
• Left lobe
• Caudate lobe
• Quadrate lobe

Question 18

Where do structures enter and leave the liver?

Answer 18

Porta hepatis

Question 19

What is it called when the peritoneum reflects off the liver on the posterior surface and attaches to the diaphragm?

Answer 19

Posterior coronary ligament

Question 20

At the lateral edge, the posterior and anterior coronary ligaments merge. Where do they merge?

Answer 20

Right and left triangular ligaments

Question 21

What is the bare area of the liver?

Answer 21

As the peritoneum comes off the liver, there is a region of the liver that is devoid of visceral peritoneum (duller and more roughened)

Question 22

How many segments can the liver be split into?

Answer 22

8

Question 23

What does each segment of the liver recieve?

Answer 23

Its own arterial blood supply, own venous supply, own duct system for secreting bile (biliary system)

Question 24

What does the hepatic vein drain into?

Answer 24

IVC

Question 25

Where is the portal triad contained?

Answer 25

Free edge of lesser omentum (hepatoduodenal ligament)

Question 26

What structures are found within the portal triad?

Answer 26

- Hepatic artery proper - Common bile duct - Portal vein

Question 27

What forms the common bile around?

Answer 27

From the gall bladder, the cystic duct (bottom) meets the hepatic duct (top) to form the common bile duct

Question 28

Where does the cystic artery come from?

Answer 28

Right hepatic artery

Question 29

What does the cystic artery?

Answer 29

Gall bladder

Question 30

What is the hepatoportal vein a combination of?

Answer 30

Majority of the veins coming from the GI tract --> splenic vein, IMV, SMV

Question 31

Where is the splenic artery found?

Answer 31

Superior aspect of pancreas

Question 32

Where is the splenic vein found?

Answer 32

Inferior aspect of pancreas

Question 33

Where does the IMV drain into?

Answer 33

Drains hindgut into splenic vein

Question 34

What is the hepatoportal vein formed by?

Answer 34

IMV, SMV, splenic (IMV drains hindgut, meeting splenic vein that then meets with SMV)

Question 35

What also drains into hepatoportal vein (small contribution)?

Answer 35

Short gastric vein

Question 36

Are the inferior mesenteric vessels intra or retroperitoneal?

Answer 36

Retroperitoneal

Question 37

What are the branches of the IMA?

Answer 37

1. Left colic 2. Sigmoidal 3. Superior rectal

Question 38

What is the anastomotic loops between IMA and SMA?

Answer 38

Marginal artery

Question 39

What does the middle colic join with to form marginal artery?

Answer 39

Some branches of the left colic

Question 40

What is importance of marginal artery in times of decreased blood supply in IMA (e.g. during aneurysm)?

Answer 40

Can still provide hindgut with arterial blood via marginal artery which receives blood from SMA

Question 41

What does the left colic artery supply?

Answer 41

The descending colon and splenic flexure

Question 42

What vertebral level does the sigmoid colon meet the rectum? What is this junction called?

Answer 42

S3 Rectosigmoid junction

Question 43

What is a portosystemic anastomosis?

Answer 43

Collateral communication between portal and systemic venous system

Question 44

What is cause of varices?

Answer 44

An increase in blood within vein (hypertension) causes them to become swollen or enlarged

Question 45

What can portal hypertension lead to?

Answer 45

Blood that usually courses to liver (portal system) now courses to IVC (systemic system) causing an enlargement of these vessels

Question 46

How can portal hypertension affect the ligamentum teres?

Answer 46

Can cause it to reopen

Question 47

What is the ligamentum teres?

Answer 47

Remnant of umbilical vein --> round ligament of the liver (thickened structure at posterior aspect of falciform ligament)