Vasculature, innervation and lymphatics of the GI tract

Question 1

What organs does the coeliac trunk supply

Answer 1

Oesophagus
Spleen
Stomach
Liver
Gall bladder
Pancreas
1st and 2nd part of duodenum

Question 2

What does the superior mesenteric artery supply

Answer 2

3rd and 4th part of the duodenum
Jejunum
Ileum
Appendix
Ascending colon
Caecum
Proximal 2/3 of transverse colon

Question 3

What does the inferior mesenteric artery supply

Answer 3

Distal 1/3 of transverse colon 
Descending colon
Sigmoid colon
Rectum
Upper anal canal
Urogenital Sinus

Question 4

3 main branches of coeliac trunk

Answer 4

left gastric
splenic
common hepatic

Question 5

Where does the coeliac trunk arise from?

Answer 5

Anterior surface of abdominal aorta at the vertebral level of T12

Question 6

Where is the left gastric artery found and what branches does it give off

Answer 6

Upper part of the lesser curvature of stomach

Oesophageal branches

Question 7

Where does the splenic artery travel to and what branches does it give off

Answer 7

Travels left towards the spleen along the superior border of the pancreas
Tortuous course
Gives branches to neck, body and tail of pancreas
Gives off short gastric branches and left gastroepiploic

Question 8

What does the splenic artery and branches supply

Answer 8

Spleen
Neck, body and tail of pancreas

Short gastric branches - fundus of stomach
Left gastroepiploic - upper part of greater curvature of the stomach

Question 9

What are the two terminal branches of the common hepatic artery

Answer 9

Hepatic artery proper

Gastroduodenal artery

Question 10

What is the course of the hepatic artery proper and what does it supply

Answer 10

Ascends towards liver in the free edge of the lesser omentum, divides into right and left hepatic arteries
Right hepatic artery supplies the gallbladder by the cystic artery

Question 11

What branches does the gastroduodenal artery give and what do they supply

Answer 11

Gives right gastroepiploic artery - lower part of greater curvature

Superior pancreaticoduodenal artery - splits into anterior and posterior branches that supply head of pancreas and duodenum

Question 12

What does the right gastroepiploic artery anastomose with

Answer 12

L gastroepiploic artery

Question 13

What does the right gastric artery anastomose with

Answer 13

Left gastric artery

Question 14

Where is the superior mesenteric artery found

Answer 14

Arises from the anterior surface of the abdominal aorta at vertebral level L1
Lies behind the neck of the pancreas
Crosses anteriorly over the 3rd part of the duodenum

Question 15

What is the inferior pancreaticoduodenal artery

Answer 15

First branch of superior mesenteric artery
Splits into anterior and posterior branches
Supplies duodenum and head and uncinate process

Question 16

Branches of superior mesenteric on the left

Answer 16

numerous jejunal and ileal arteries supplying the jejunum and most of the ileum

Question 17

3 branches of right side of superior mesenteric artery

Answer 17

Middle colic artery
Right colic artery
Ileocolic artery

Question 18

Where does the middle colic artery supply and what are it’s branches

Answer 18

Enters transverse mesocolon
Supplies proximal 2/3 of transverse colon
Left and right branch
Left branch anastomoses with left colic and right branch anastomoses with right colic

Question 19

Where does the right colic supply and what are its two branches

Answer 19

Supplies ascending colon

Ascending branch and descending branch

Question 20

Where is the ileocolic artery found and what are it’s branches and theie supplies

Answer 20

Passes into right iliac fossa
Superior branch - ascending colon
Inferior branch towards ileocolic junction

Question 21

What arteries are found in the inferior branch of the ileocolic artery

Answer 21

Colic branches
Caecal arteries
Appendicular artery
Ileal branch

Question 22

Where is the inferior mesenteric artery found

Answer 22

Arises from the anterior surface of the abdominal aorta at vertebral level of L3
About 1.5 inches above the bifurcation of the aorta
Passes downwards and to the left, crossing the left common iliac artery

Question 23

Branches of the inferior mesenteric artery

Answer 23

Left colic artery
Several sigmoid arteries
Superior rectal artery

Question 24

What does the left colic artery supply

Answer 24

Ascending branch - supplies distal 1/3 of transverse colon and upper part of Descending colon
Descending branch- Lower part of descending colon

Question 25

What is the superior rectal artery

Answer 25

Terminal branch of inferior mesenteric artery Descends into pelvic cavity to supply the rectum to the level of the internal anal sphincter Anastomosis with middle rectal artery and inferior rectal artery

Question 26

What 3 arteries supply the rectum

Answer 26

Superior rectal artery - from inferior mesenteric artery Middle rectal artery - branch of the internal iliac artery Inferior rectal artery - branch of the internal pudendal artery Anastomose together

Question 27

What is the marginal artery

Answer 27

Single arterial trunk that connects superior mesenteric and inferior mesenteric arteries Runs along inner border of the colon Formed by anastomosing branches of the ileocolic, right colic, middle colic, left colic and sigmoid arteries

Question 28

What are the two venous systems of the abdomen

Answer 28

Portal venous system - venous blood passes through the liver for processing Systemic venous system - venous blood that joins the inferior vena cava without going to the liver

Question 29

How is the IVC formed

Answer 29

Union of common iliac veins at L5

Question 30

How is the protal vein formed

Answer 30

Union of splenic vein and superior mesenteric vein Behind neck of pancreas L2

Question 31

Course of the portal vein

Answer 31

Enters the liver and breaks up into sinusoids and then hepatic veins that drain into the IVC

Question 32

What is present between lobules of the liver

Answer 32

Portal triads - branch of hepatic artery, branch of portal vein and a bile duct tributary

Question 33

How does blood supply and drainage occur in liver lobule

Answer 33

Arterial and portal venous blood passes into sinusoids between liver cells Bile passes travels in the opposite direction, towards the bile duct to exit the liver

Question 34

What does the superior mesenteric vein drain?

Answer 34

Small intestine (jejunal and ileal veins) Caecum (ileocolic v.) Ascending colon (right colic v.) proximal part of transverse colon (middle colic v.) Also receives right gastroepiploic v., inferior pancreaticoduodenal v.

Question 35

Pathway of superior mesenteric vein

Answer 35

Begins in right iliac fossa, ascends in the mesentery of small intestine Joins the splenic vein behind the neck of pancreas

Question 36

What does the inferior mesenteric vein drain

Answer 36

Rectum (rectal veins) Sigmoid colon (sigmoid veins) Descending colon (left colic vein) Distal transverse colon (left colic vein)

Question 37

Pathway of inferior mesenteric vein

Answer 37

Begins as the superior rectal vein Receives sigmoid vein and left colic vein It ascends behind the body of he pancreas and joins the splenic vein

Question 38

Tributaries of the portal vein

Answer 38

``` Right and left gastric vein Cystic veins Paraumbilical veins Superior mesenteric vein Splenic vein ```

Question 39

What are the tributaries of splenic vein and what does it drain

Answer 39

Short gastric vein, left gastroepiploic vein from greater curvature, pancreatic veins and inferior mesenteric veins Drains the spleen

Question 40

Communications between portal ns systemic venous systems

Answer 40

Oesophageal - gastroesophageal junction Rectal - superior rectal vein anastomoses with the middle and inferior veins Paraumbilical - paraumbilical veins anastomose with veins draining the anterior abdominal wall

Question 41

What are the 3 preaortic lymph nodes that drain the abdomen and what do they drain into

Answer 41

Coeliac group, superior mesenteric group and inferior mesenteric group Eventually drain into cisterna chyli -> thoracic duct

Question 42

Key difference between sympathetic pathway and parasympathetic pathway

Answer 42

Sympathetic - short preganglionic neuron, log post ganglionic neuron Parasympathetic - long preganglionic and short post ganglionic

Question 43

Pathway of sympathetic division of GI tract

Answer 43

Originate from thoracic and lumbar region Pre-ganglionic fibres leave spinal cord and synapse in sympathetic chain ganglia or travel through sympathetic chain without synapsing Long postganglionic fibres then travel to target tissue

Question 44

Pathway of parasympathetic division of GI tract neurons

Answer 44

Originate in the brainstem in the cranial nerves or from the sacral region for controlling pelvic region Vagus nerve innervates abdominal viscera Pelvic nerves innervate pelvic viscera Long preganglionic fibres Ganglia are usually near or on target tissue Short post-ganglionic fibres

Question 45

Sympathetic splanchnic nerves in the abdomen

Answer 45

Greater splanchnic - coeliac Lesser splanchnic - aorticorenal, sometimes coeliac, superior mesenteric Least splanchnic - aorticorenal Lumbar splanchnic - inferior mesenteric ganglion

Question 46

4 main sympathetic ganglia

Answer 46

Coeliac Aorticorenal Superior mesenteric Inferior mesenteric

Question 47

What parts of the GI tract does the vagus nerve supply

Answer 47

Supplies oesophagus to proximal part of colon (foregut, midgut) and other organs derived from the foregut and midgut

Question 48

Parasympathetic splanchnic nerves

Answer 48

Pelvic splanchnic (S2-S4) Supplies hindgut