Stomach, Midgut and Associated Arteries Flashcards
What are the anterior boundaries of the lesser sac?
Stomach, lesser omentum
What are the posterior boundaries of the lesser sac?
Pancreas
What are the superior boundaries of the lesser sac?
Liver, diaphragm
What are the inferior boundaries of the lesser sac?
Omental bursa
What are the lateral boundaries of the lesser sac?
Left: Spleen
Right: Epiploic foramen, liver
Is the cardiac orifice an anatomical sphincter?
No
Is the pylorus an anatomical sphincter?
Yes
At what vertebral level does the pylorus normally lie?
L1
This is the transpyloric plane
Stomach receives parasympathetic innervation from which nerves?
Left and right vagus nerves
How does the left vagus nerve come to lie anteriorly to the stomach and the right posteriorly?
Rotation of the stomach
What is a hiatus hernia?
Stomach pushing through diaphragm
At what vertebral level is the coeliac trunk given off?
T12
Which section of the gut is supplied by the coeliac trunk?
Foregut
Which branch of the coeliac trunk runs along the lesser curvature of the stomach?
Left gastric artery
Which vessel runs along the greater curvature of the stomach?
Gastroepiploic arteries (left and right, they anastomose)
Which branch of the coeliac trunk is normally the largest, with a very tortuous path?
Splenic
What structure demarcates the midgut?
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
Of the jejunum and ileum, which is a deeper red colour?
Jejunum
Of the jejunum and ileum, which is smaller in diameter?
Ileum (~3cm)
Of the jejunum and ileum, which has thinner, lighter walls?
Ileum
Of the jejunum and ileum, which has the greater vasculature?
Jejunum
Of the jejunum and ileum, which has shorter vasa recta?
Ileum
Of the jejunum and ileum, which has fewer, but larger arcades?
Jejunum
Of the jejunum and ileum, which has less fat in its mesentery?
Jejunum
Of the jejunum and ileum, which has larger, taller plicae circulares?
Jejunum
Of the jejunum and ileum, which has fewer Peyer’s patches?
Jejunum
What is Meckel’s diverticulum?
Bulge in the small intestine, vestigial remnant of the vitelline duct
What properties of the large intestine distinguish it from the small intestine?
- Greater calibre
- Taeniae coli (three make up the longitudinal muscle layer)
- Haustra (sacculations)
- Appendices epiploicae (fatty tags)
What is diverticulosis?
Pouching of the colon, usually in sigmoid region
What is diverticulitis?
Inflammation of a divertuli due to infection, probably due to trapped faeces
What structures merge at the root of the appendix?
The three taeniae coli
From where does the appendicular artery originate?
Iliocolic artery
Why is it dangerous to use laxatives in cases of suspected appendicitis?
They can cause vigorous contraction of the gut wall, which could rupture an inflamed appendix
Where is the site of maximum tenderness in appendicitis?
McBurney’s Point (surface marking of the appendix)
Lies one third of the way along the imaginary line from the ASIS to the umbilicus
How can appendicitis lead to pain in the right shoulder?
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
If a surgeon needs to mobilise the ascending colon (e.g. during an appendectomy) which side should they incise?
The lateral side
Many vessels approach the medial side of the colon. Lateral resection avoids damaging these blood vessels
At what vertebral level is the superior mesenteric artery given off the aorta?
L1
What is the relationship between the superior mesenteric artery and the duodenum?
SMA descends over the third part of the duodenum, it’s first branch supplies the duodenum (inferior pancreaticoduodenal artery)
Where does the superior pancreaticoduodenal artery arise from?
Gastroduodenal artery
What are the branches of the SMA?
Inferior pancreaticoduodenal
Jejunal branches
Ileal branches
Ileocolic
Right colic
Middle colic
