Stomach, Midgut and Associated Arteries

Question 1

What are the anterior boundaries of the lesser sac?

Answer 1

Stomach, lesser omentum

Question 2

What are the posterior boundaries of the lesser sac?

Answer 2

Pancreas

Question 3

What are the superior boundaries of the lesser sac?

Answer 3

Liver, diaphragm

Question 4

What are the inferior boundaries of the lesser sac?

Answer 4

Omental bursa

Question 5

What are the lateral boundaries of the lesser sac?

Answer 5

Left: Spleen

Right: Epiploic foramen, liver

Question 6

Is the cardiac orifice an anatomical sphincter?

Answer 6

No

Question 7

Is the pylorus an anatomical sphincter?

Answer 7

Yes

Question 8

At what vertebral level does the pylorus normally lie?

Answer 8

L1

This is the transpyloric plane

Question 9

Stomach receives parasympathetic innervation from which nerves?

Answer 9

Left and right vagus nerves

Question 10

How does the left vagus nerve come to lie anteriorly to the stomach and the right posteriorly?

Answer 10

Rotation of the stomach

Question 11

What is a hiatus hernia?

Answer 11

Stomach pushing through diaphragm

Question 12

At what vertebral level is the coeliac trunk given off?

Answer 12

T12

Question 13

Which section of the gut is supplied by the coeliac trunk?

Answer 13

Foregut

Question 14

Which branch of the coeliac trunk runs along the lesser curvature of the stomach?

Answer 14

Left gastric artery

Question 15

Which vessel runs along the greater curvature of the stomach?

Answer 15

Gastroepiploic arteries (left and right, they anastomose)

Question 16

Which branch of the coeliac trunk is normally the largest, with a very tortuous path?

Answer 16

Splenic

Question 17

What structure demarcates the midgut?

Answer 17

Major duodenal papilla (halfway along 2nd part of duodenum) separates foregut and midgut

Junction between midgut and hindgut is two-thirds of the way along the transverse colon

Question 18

Of the jejunum and ileum, which is a deeper red colour?

Answer 18

Jejunum

Question 19

Of the jejunum and ileum, which is smaller in diameter?

Answer 19

Ileum (~3cm)

Question 20

Of the jejunum and ileum, which has thinner, lighter walls?

Answer 20

Ileum

Question 21

Of the jejunum and ileum, which has the greater vasculature?

Answer 21

Jejunum

Question 22

Of the jejunum and ileum, which has shorter vasa recta?

Answer 22

Ileum

Question 23

Of the jejunum and ileum, which has fewer, but larger arcades?

Answer 23

Jejunum

Question 24

Of the jejunum and ileum, which has less fat in its mesentery?

Answer 24

Jejunum

Question 25

Of the jejunum and ileum, which has larger, taller plicae circulares?

Answer 25

Jejunum

Question 26

Of the jejunum and ileum, which has fewer Peyer's patches?

Answer 26

Jejunum

Question 27

What is Meckel's diverticulum?

Answer 27

Bulge in the small intestine, vestigial remnant of the vitelline duct

Question 28

What properties of the large intestine distinguish it from the small intestine?

Answer 28

- Greater calibre - Taeniae coli (three make up the longitudinal muscle layer) - Haustra (sacculations) - Appendices epiploicae (fatty tags)

Question 29

What is diverticulosis?

Answer 29

Pouching of the colon, usually in sigmoid region

Question 30

What is diverticulitis?

Answer 30

Inflammation of a divertuli due to infection, probably due to trapped faeces

Question 31

What structures merge at the root of the appendix?

Answer 31

The three taeniae coli

Question 32

From where does the appendicular artery originate?

Answer 32

Iliocolic artery

Question 33

Why is it dangerous to use laxatives in cases of suspected appendicitis?

Answer 33

They can cause vigorous contraction of the gut wall, which could rupture an inflamed appendix

Question 34

Where is the site of maximum tenderness in appendicitis?

Answer 34

McBurney's Point (surface marking of the appendix) Lies one third of the way along the imaginary line from the ASIS to the umbilicus

Question 35

How can appendicitis lead to pain in the right shoulder?

Answer 35

Pus from an appendix abscess can track upwards in the right paracolic gutter to reach the subphrenic space. Irritation of the diaphragm leads to shoulder pain

Question 36

If a surgeon needs to mobilise the ascending colon (e.g. during an appendectomy) which side should they incise?

Answer 36

The lateral side Many vessels approach the medial side of the colon. Lateral resection avoids damaging these blood vessels

Question 37

At what vertebral level is the superior mesenteric artery given off the aorta?

Answer 37

L1

Question 38

What is the relationship between the superior mesenteric artery and the duodenum?

Answer 38

SMA descends over the third part of the duodenum, it's first branch supplies the duodenum (inferior pancreaticoduodenal artery)

Question 39

Where does the superior pancreaticoduodenal artery arise from?

Answer 39

Gastroduodenal artery

Question 40

What are the branches of the SMA?

Answer 40

Inferior pancreaticoduodenal Jejunal branches Ileal branches Ileocolic Right colic Middle colic