Part 5: Gastrointestinal Tract

Question 1

What binds oesophagus to diaphragm?

Answer 1

Phreno-oesophageal ligaments (firmly bound)

Question 2

What is the surface marking of the oesophagus projecting through diaphragm?

Answer 2

7th CC, thumbs breadth to left of sternum and level with T10

Question 3

The posterior oesophagus is said to scarcely possess a serous coat why?

Answer 3

Posterior oesophagus is much short than anterior due to slope of diaphragm and stomach. Fold of peritoneum is not firmly attached due to the shortness of abdominal oesophagus and also allows elongation of oesophagus in movement

Question 4

What are the different parts to the stomach?

Answer 4

Cardia (where oesophagus enters)
Fundus (above level of cardia)
Body (fundus to angular notch)
Pylorus (angular notch to gastroduodenal junction
Greater and lesser curvatures

Question 5

How is the stomach fixed to abdomen?

Answer 5

Entire stomach is within peritoneum. Fixed at pylorus and cardia, relatively mobile in middle to allow for distension

Question 6

What is the blood supply of the stomach?

Answer 6

L + R gastric
L + R gastroepiploic
Short gastric

Question 7

What is the venous drainage of stomach?

Answer 7

Same as arterial
L + R gastric veins
L + R gastroepiploic veins
Short gastric vein
Venous drainage into portal vein, SMA or splenic vein
1 vein without arterial companion is prepyloric vein which overlies pylorus and drains to portal vein

Question 8

What is the lymph drainage of the stomach?

Answer 8

Lymphoid follicles in mucosa to outlying nodes to coeliac nodes to cisterna chyli

Question 9

What is the nerve supply to the stomach?

Answer 9

Sympathetic fibres run with arteries
Parasympathetic control motility and secretion and come from anterior and posterior vagal trunk. Anterior trunk gives hepatic branch and posterior branch gives coeliac branch to coeliac ganglion

Question 10

The stomach has an extra muscle layer, what is it?

Answer 10

Innermost oblique muscle.
Fibres loop over fundus, pass in oblique direction to axis of organ, lie vertical in erect trunk providing gravitational support

Question 11

What is the stomach mucosa?

Answer 11

Parietal (acid secreting cells) in body

Pyloric type G cells in pylorus (gastrin secreting)

Question 12

What is the shape of the duodenum?

Answer 12

C-shaped around head of pancreas

Question 13

What are the parts of duodenum?

Answer 13

1st (superior): 2”. L1. Runs upwards and backwards.
2nd (descending): 3”. R L2. Curves downwards over hilum of R kidney. Bile duct on posteriormedial wall. Lies in both supra and infracolic compartments (crossed by transverse mesocolon)
3rd (Horizontal): 4” L3. R to L. Lies on aorta at commencement IMA. Crossed by bowel mesentery (in both L + R infracolic spaces)
4th (ascending): 1”. Lt of L2. ascends to L of aorta on the L psoas which fixes DJ flexure

Question 14

What are the lengths of the duodenum parts?

Answer 14

2,3,4 and 1 inches respectively

Question 15

What supports the DJ flexure?

Answer 15

Suspensory muscle of the diaphragm (muscle/ligament of Trietz)

Question 16

What is the mucosa of the duodenum?

Answer 16

Plicae circularis

Apart from 1st portion which is smooth (duodenal cap on barium)

Question 17

What is the blood supply of the duodenum?

Answer 17

Superior and inferior pancreaticoduodenal arteries

1st part may recieve supply from heaptic, CH, GD, sup PD R gastric or R GE

Question 18

Where does the jejunum begin?

Answer 18

DJ flexure, jejunum is defined as having mesentery where as duodenum is retroperitoneal

Question 19

How can one differentiate between ileum and jejunum?

Answer 19

Jejunum is wider bore, thicker wall when palpated with long straight arteries in mesentery.
Ileum is narrower with thinner wall. Straight arteries of arcade are normally shorted with more fat in mesentery. Also Peyer’s patches can often be seen on ileum.

Question 20

How long is the jejunum and ileum?

Answer 20

4-6 metres of which jejunum is 2/5ths

Question 21

What is the blood supply for jejunum and ileum?

Answer 21

Arterial arcade arising from SMA with ileocolic contribution near terminal ileum

Question 22

What are the bounds of the caecum?

Answer 22

Below ileocecal junction to appendix, blind pouch

Question 23

What are the tineae coli?

Answer 23

Longitudinal muscle of large bowel form 3 flat bands, one anterior, one posteromedial and one posterolateral.
Converge on appendix

Question 24

What is the ileocecal recess?

Answer 24

Recess between fold of terminal ileum mesentery and ant wall of caecum. Can be site of internal hernia

Question 25

What is the commonest position of appendix?

Answer 25

Retrocolic in operations but thought to be retroileal in health

Question 26

What supplies appendix?

Answer 26

Mesoappendix - appendicular artery (often double)

Question 27

What are appendices epiploicae?

Answer 27

Bulbous pouches of peritoneum distended with fat projecting through serous coat of large bowel. When mucous membranes herniate through these vascular perforations it is known as diverticulosis

Question 28

What are the approximate lenghts of different parts of colon?

Answer 28

Ascending: 15cm
Transverse: 45cm
Descending: 30cm
Sigmoid: 45cm

Question 29

Describe the mesentery attachment to sigmoid colon

Answer 29

Hinged on mesentery but not completely fused - forms a A base with diverging limbs. Apex is at bifurcation of common artery. Lateral limb attached to external iliac 1/2 down to inguinal ligament
Medial extends to midline at S3. Mesentery fans out from 10cm base to a 40cm border with sigmoid

Question 30

Which part of bowel has most extensive appendices epiploicae and is therefore most likely to get diverticulosis?

Answer 30

Sigmoid colon