Foregut, Midgut & Hindgut

Question 1

Where does the Oesophagus start and end?

Answer 1

Distal laryngopharynx @C6/7

Ends at cardia of stomach @T11

Question 2

How long is the Oesophagus?

Answer 2

40cm from incisors to stomach. (Important when inserting tubes)

Question 3

Describe the right crus of diaphragm

Answer 3

Loop of muscle; forms lower oesophageal sphincter (Not a ‘true’ anatomical sphincter, because it is not a ring of muscle). @T11-12

Question 4

How does the epithelium change between the lower oesophagus and stomach?

Answer 4

Stratified squamous in oesophagus

Columnar epithelium in stomach

Question 5

What are mesenteries?

Answer 5

Mesenteries (ventral & dorsal) are double-layered folds of peritoneum attaching the gut tube to the body wall.

Question 6

Of the foregut, midgut and hindgut, which have dorsal or ventral mesenteries, or both?

Answer 6

Foregut - Dorsal and Ventral

Mid and Hindgut - Dorsal ONLY

Question 7

Describe the lesser omentum

Answer 7

Peritoneum between the stomach & liver

Composed of 2 Ligaments: Hepatoduodenal and Hepatogastric

Question 8

Describe the greater omentum

Answer 8

The peritoneum hanging off the greater curvature of stomach

Question 9

The Hepatoduodenal ligament contains which 3 structures?

Answer 9

Portal Vein
Hepatic Artery
Common Bile Duct

Question 10

Peritoneal folds develop from…

They differentiate into…

Answer 10

Develop from Dorsal and Ventral mesenteries

Omenta, Mesenteries and Ligaments

Question 11

Name the omenta of the peritoneal cavity

Answer 11

Greater Omentum 
(From dorsal mesentery)

Lesser Omentum
(From ventral mesentery)

Question 12

Name the mesenteries of the peritoneal cavity

Answer 12

Mesentery
(Suspends small bowel)

Transverse Mesocolon
(Suspends transverse colon)

Sigmoid Mesocolon
(Suspends sigmoid colon)

Mesoappendix
(suspends appendix)

Question 13

Name the ligaments of the peritoneal cavity

Answer 13

Hepatoduodenal
(Part of lesser omentum)

Hepatogastric
(Part of lesser omentum)

Splenorenal & Gastrosplenic Ligs.
(From spleen to kidney / from stomach to spleen)

Question 14

What level does the coeliac trunk come off at?

Answer 14

T12

Question 15

What level does the SMA come off at?

Answer 15

L1

Question 16

What level does the IMA come off at?

Answer 16

L3

Question 17

What branches off the coeliac trunk?

Answer 17

Common Hepatic, Left Gastric & Splenic arteries

Question 18

What could damage the gastroduodenal artery?

Answer 18

Peptic Ulcers

Especially posterior to 1st part of duodenum.

Question 19

Name the retroperitoneal organs

Answer 19

S: suprarenal (adrenal) gland
A: aorta/IVC
D: duodenum (second and third part)
P: pancreas (except tail)
U: ureters
C: colon (ascending and descending)
K: kidneys
E: (o)esophagus
R: rectum

Question 20

Name the intraperitoneal organs

Answer 20

S = Stomach
A = Appendix
L = Liver
T = Transverse colon
D = duodenum (only the 1st part)
S = Small intestines
P = Pancreas (only the tail)
R = Rectum (only the upper 3rd)
S = Sigmoid colon
S = Spleen

Question 21

Describe the duodenum anatomically.

Answer 21

The duodenum is C-shaped and is retroperitoneal (except for the 1st part)
Composed of 4 Parts

Question 22

What ligament is a useful landmark for the duodeno-jejunal flexure

Answer 22

Ligament of Treitz
Marker point for ‘upper’ vs ‘lower’ GI bleed
Suspends the 4th pt. (ascending part) of the duodenum to the posterior abdominal wall.

Question 23

Where does the arterial supply for the pancreas and and duodenum come from?

Answer 23

Superior Pancreaticoduodenal artery (from CT)

anastamoses with Inferior Pancreaticoduodenal artery (from SMA).

Question 24

Where does the caecum sit?

Answer 24

Right Iliac Fossa

Question 25

What is Teniae Coli?

Answer 25

Longitudinal muscle of colon

Sits in 3 bands that begin at caecum (appendix) and end by covering the rectum

Question 26

What are the pouches of the large intestine called?

Answer 26

Haustra

Question 27

What position is the appendix normally in?

Answer 27

Retrocaecal in 60% of people.

Question 28

What is Intussusception?

Answer 28

Proximal segment of bowel telescopes into an adjacent distal segment
Typically in ileocecal junction

Question 29

Describe the appendix

Answer 29

Blind ended sac

Has own mesentery and artery (SMA -> Ileocolic a. -> Appendicular a.)

Question 30

Why is the hepatorenal recess important to consider in a supine patient, with peritonitis?

Answer 30

Infections can spread from under the diaphragm to pelvic cavity and vice versa via Paracolic Gutters.

Question 31

Describe the arterial supply of the hindgut (route).

Answer 31

IMA -> Left colic, Sigmoidal (Join the Marginal A.)
and Superior Rectal

SMA, IMA and Internal Iliac anastamose (Marginal artery)

Question 32

Where are the 3 important Portosystemic Anastomoses? What are the clinically significant conditions related to these?

Answer 32

Lower End of the Oesophagus (!Oesophageal Varices)
Lower part of Anal Canal (!Anorectal Varices)
Umbilical Region of Anterior Abdo Wall (!Caput Medusae)

Question 33

What are Haemorrhoids?

Answer 33

Prolapsed varicosity of internal venous plexus from excessive straining during defecation.
NOT Anorectal Varices!

Question 34

What positions are Haemorrhoids classically reported on the Anus?

Answer 34

3, 7 and 11 o’clock

Question 35

Describe what you might see in a barium contract test, if the patient had colon carcinoma?

Answer 35

Apple core sign

Question 36

Where do GI structures’ lymph drain to?

Answer 36

Thoracic duct and cisterna chyli