Week 6: GI tract

Question 1

Celiac Trunk (supply)

Answer 1

Supplies foregut: abdominal oesophagus, stomach, duodenum, pancreas,liver, gall bladder, spleen.

Question 2

Superior Mesenteric Artery (supply)

Answer 2

Supplies midgut: Duodenum, pancreas, jejunum, ileum, caecum, appendix, ascending colon, transverse colon.

Question 3

Inferior Mesenteric Artery (supply)

Answer 3

Supplies hindgut: Transverse colon, descending colon, sigmoid colon, rectum

Question 4

Abdominal Aorta (Unpaired Branches)

Answer 4

Celiac trunk, superior and inferior mesenteric arteries

Question 5

Celiac Trunk (location and arteries)

Answer 5

Arises at T12/L1 from abdominal aorta.

Gives rise to the splenic artery, the common hepatic and the left gastric.

Question 6

Splenic Artery

Answer 6

• Classic tortuous appearance along pancreas superiorly
• Some branches will travel within splenorenal ligament and greater omental ligaments
• Supplies pancreas, stomach, spleen

Question 7

Common hepatic artery

Answer 7

Gives off the proper hepatic artery and the gastroduodenal artery.

Pathway to liver within hepatoduodenal ligament (lesser omentum).

Supplies: stomach, duodenum, pancreas, liver and gall bladder

Question 8

Left gastric artery

Answer 8

• Smaller branch, will travel within gastrohepaticligament (L.O)
• Supplies stomach and abdominal oesophagus

Question 9

Potential anastomoses of portal and systemic veins

Answer 9

1. Oesophagus
   Left gastric ———– azygous
2. Umbilicus/anterior abdominal wall
   Paraumbilical ——— epigastric
3. Secondarily Retroperitoneal Viscera + Liver
   Bare areas of these viscera
   Ex. left colic —- lumbar
4. Rectum
   Superior rectal ——- middle/inferior rectal

Question 10

What does the ilio-inguinal n. innervates?

Answer 10

Branch from the lumbar plexus. Pass downwards across quadratus lumborum, second most superior nerve coming out of the spine.

Sensory: Transversus abdominis and internal oblique muscles, anteromedial aspect of the thigh, skin over parts of the external genitalia

Motor: Transversus abdominis and internal oblique muscles

Question 11

What does the ilio-hypogastric n. innervates?

Answer 11

Branch from the lumbar plexus. Pass downwards across quadratus lumborum, most superior nerve coming out of the spine.

Motor: Transversus abdominis, internal oblique, conjoint tendon.

Sensory: External abdominal oblique, transversus abdominis, internal abdominal oblique; Skin of the suprapubic region and posterolateral aspect of gluteal region.

Question 12

Genito-femoral n.

Answer 12

Branch from the lumbar plexus. Passes on top of psoas major and divides into the genital branch and femoral branch. The genital branch runs through the inguinal canal whilst the femoral branch passes posterior to the inguinal ligament.

Question 13

The greater omentum

Answer 13

Mesentery from the greater curvature of the stomach that flows down in front of the intestines, folds under itself and re-attaches back into the transverse colon.

Question 14

The lesser omentum

Answer 14

Mesentery from the lesser curvature of the stomach also attaching to the underside of the liver and the diaphragm.

Question 15

“Ligaments” that together form the GREATER omentum

Answer 15

• Gastrocolic ligament (stomach - transverse colon)
• Gastrosplenic ligament (stomach - spleen)
• Gastrophrenic ligament (stomach - diaphragm)

Question 16

“Ligaments” that together form the LESSER omentum

Answer 16

• Gastrohepatic ligament (stomach - liver)

- Hepatoduodenal ligament (liver - duodenal)

Question 17

The pre-aortic lymph nodes are associated with

Answer 17

unpaired viscera

Question 18

The para-aortic lymph nodes are associated with

Answer 18

paired viscera

Question 19

Lymph nodes from the abdominal region drain into

Answer 19

cisterna chyli which then drains into the thoracic duct