Embryology

Question 1

Epithelium of mucosa and associated ducts and glands are derived from the ___derm

Answer 1

endoderm

Question 2

The part of the GI tract derived from mesoderm

Answer 2

most of it - BAR epithelium
lamina propria, muscularis mucosa+externa
submucosal and serosa connective tissue

Question 3

ventral mesentery develops to form:

Answer 3

falciform ligament and lesser omentum

Question 4

dorsal mesogastrium develops to form:

Answer 4

greater omentum

Question 5

4 embryological mesenteries =

Answer 5

ventral mesentery

dorsal mesogastrium, dorsal mesoduodenum and dorsal mesocolon

Question 6

Oesophagus is distinguishable at __
Circular muscle develops at ___
Longitudinal at __

Answer 6

4wks
5wks
8wks

Question 7

The stomach starts as a ______ at wk _
90 degree AP rotation at ___
90 degree longiudinal rotation at __

Answer 7

dilatation of the caudal part of foregut wk4
35 days
56 days

Question 8

At 10 wks liver is large because

Answer 8

has a large haemopoeitic role

Question 9

Hepatic diverticulum is derived from __derm

it grows into the ___

Answer 9

endoderm

septum transversum mesoderm

Question 10

hepatocytes and biliary tree lining are derived from ___derm

Answer 10

endoderm

Question 11

haemopoeitic liver cells, Kupffer cells and connective tissue of liver and gallbladder are from ___derm

Answer 11

mesoderm

Question 12

Pancreas comes from the fusion of __+__buds

Answer 12

dorsal and ventral pancreatic

Question 13

annular pancreas =

Answer 13

ventral bud is bilobed and wraps around duodenum causing duodenal stenosis

Question 14

Spleen is derived from __derm at wk _
Is haemopoeitic until ___ then becomes __
In foetus it is ___ , these recede before birth

Answer 14

mesoderm 5th wk
wk 15-18 lymphatic
lobular

Question 15

Midgut - for most of its development it communicates with __ this communication narrows until it is only held by ___

Answer 15

yolk sac

vitelline duct

Question 16

Midgut herniates ventrally from embryo at wk__

reenters at wk __

Answer 16

5

10

Question 17

On day 50 midgut rotates 90degrees around ___

___ is on the left (with caecal bud) and ___ on the right

Answer 17

superior mesenteric artery
caudal on L
cranial on R

Question 18

Developmental defects of midgut= (6)

Answer 18

vitelline fistula, vitelline cyst, vitelline ligament (due to bad re-entry
omphalocele
meckel’s diverticulum
non-rotation

Question 19

Omphalocele =

Answer 19

abdominal hernia into umbilical cord

Question 20

Cloaca becomes the +

an expansion of __derm

Answer 20

hiindgut and urogenital system

endoderm

Question 21

Lumen of cloaca is occluded at __ as ___proliferates

___form and it is recanalised at wk _ with ___

Answer 21

wk5/6 mucosa
vacuoles
wk 9
villi