The Foregut

Question 1

how does the oesophagus develop from the ventral wall of the foregut?

Answer 1

the laryngeo-tracheal diverticulum develops from the ventral wall of the fore gut
the trachea-oesophageal septum divides the trachea from the oesophagus

Question 2

what developmental defect can occur from abnormal formation of the oesophagus and how does this occur?

Answer 2

oesophageal atresia
trachea-oesophageal fistula
incomplete separation of the laryngo-tracheal tube

Question 3

at what week does the stomach develop?

Answer 3

the 4th week

Question 4

what are the 2 rotations that the stomach undergoes in its development?

Answer 4

90 degree rotation

anterior-posterior rotation

Question 5

what is the attachment of the stomach to the ventral walls called?

Answer 5

mesogastrium

Question 6

how are the greater and lesser omental bursa created during the stomachs development?

Answer 6

the dorsal mesogastrium is pulled to the left creating the lesser sac
the ventral mesogastrium is pulled to the right creating the greater sac

Question 7

what part of the gut tube is the duodenum formed from?

Answer 7

the caudal end of the foregut and the cranial end of the midgut

Question 8

what is the blood supply of the duodenum and why?

Answer 8

the coeliac trunk and the SMA because it is formed from part of the foregut and midgut

Question 9

is the duodenum retroperitoneal or intraperitoneal?

Answer 9

retroperitoneal

Question 10

at what week does the liver primordial bud first appear?

Answer 10

week 3

Question 11

how does the bile duct form?

Answer 11

the connection between the liver and the duodenum narrows to form the bile duct

Question 12

from which structure is the gall bladder formed from?

Answer 12

ventral outgrowth from the bile duct forms the gallbladder (and the cystic duct)

Question 13

at what week is the spleen formed?

Answer 13

week 5

Question 14

how does the spleen develop?

Answer 14

mesenchymal condensation in the dorsal mesogastrium of the stomach differentiates to form the spleen

Question 15

what is the function of the spleen up to week 14?

Answer 15

haematopoietic

produces blood cells

Question 16

between what weeks is the spleen colonised by T lymphocytes?

Answer 16

week 15-17

Question 17

when does the spleen acquire its lobar shape?

Answer 17

between weeks 15-17

Question 18

what happens at week 24 in the spleen?

Answer 18

B cell precursors arrive

Question 19

when can the spleen start its lymphoid function?

Answer 19

week 23

colonised by T lymphocytes weeks 15-17 then B cell precursors at week 24

Question 20

how does the pancreas develop?

Answer 20

forms from 3 buds which grow from the endodermal lining of the duodenum
as the duodenum rotates, the dorsal and ventral buds rotate and fuse

Question 21

what is the main pancreatic duct formed from?

Answer 21

the ventral bud plus the distal part of the dorsal bud

Question 22

what part of the pancreas may form an accessory bud?

Answer 22

the proximal part of the dorsal bud

Question 23

what developmental abnormalities can occur during the development of the pancreas?

Answer 23

annular pancreas- the ventral bud fails to rotate around the duodenum properly resulting in duodenal stenosis
accessory pancreatic tissue which forms in other areas of the gut