010514 dev Flashcards
what are precursors of the GI tract?
endoderm
splanchnic mesoderm
coelomic epithelium covering the splanchnic mesoderm (forms serosa)
which portion of the primitive stomach grows faster?
dorsal part grows faster and stomach rotates 90 deg clockwise
foregut extends to where?
duodenum (first and second parts)
midgut extends to where?
transverse colon (proximal 2/3)
what does the liver bud/diverticulum form?
two portions-cranial portion becomes liver and caudal portion becomes gallbladder
why does the midgut herniate?
because it has a very small area to grow in
what structure is the midgut connected to anteriorly?
yolk stalk or vitelline duct
duodenal atresia is
complete occlusion of the duodenum (as opposed to stenosis which is partial)
can duodenal atresia cause polyhydramnios?
yes
gastroschisis
defect in anterior abd wall
abdominal viscera exposed to amniotic fluid
it’s not a hernia. it’s not covered with membranes
omphalocele
herniation of abdominal viscera into proximal umbilicus (covered with membranes)
what kind of mesentery forms the greater omentum extending from the greater curvature?
the dorsal mesentery (due to stomach rotation)
what is the ventral mesentery of the stomach attached to?
the developing liver (the ventral mesentery is known as the lesser omentum)
the jxn btwn the foregut and midgut endoderm is proximal or distal to the bile duct?
distal to
what forms a ventral U shaped tube?
midgut as it elongates
