Abdominal Embryology & Pathology Flashcards
the primordial gut forms in week ____
4
what forms the primitive gut tube?
cephalocaudal and lateral folding
the primitive gut tube is bound cephalically by the ____ and caudally by the ____
- oropharyngeal membrane
- cloacal membrane
the midgut remains temporarily connected to what embryological structure during development?
yolk sac
the ventral mesentery is derived from…
mesenchyme of septum transversum
the dorsal mesentery is a continuous sheet extending along the posterior abdominal wall from the ____ to the ____
abdominal esophagus to rectum
what is the name for the early diaphragm?
septum transversum
name the structures of the foregut
- primordial pharynx & derivatives
- lower respiratory system
- esophagus & stomach
- duodenum (proximal to bile duct opening)
- liver, biliary system (hepatic ducts, gallbladder, bile duct)
- pancreas
what 2 foregut structures are derived from ventral mesogastrum?
lesser omentum
falciform ligament
the greater omentum is derived from ____
dorsal mesogastrum
what happens to the stomach during development?
clockwise rotation (90*) on longitudinal axis, forming omental bursa
- cardia portion moves left + downward
- pyloric portion moves right + upward
the dorsal mesogastrum fuses with the ____
transverse mesocolon mesentery
what forms the duodenal C-shape during development?
stomach rotation
what pushes the duodenum to the right of the midline?
pancreas grows concurrently
the liver develops as cells start to proliferate within portions of mesoderm derived from ____
septum transversum
what forms the bare area of the liver?
as liver grows, contacts central tendon of diaphragm
name the structures of the midgut
- small intestine (includes duodenum distal to bile duct opening)
- cecum
- appendix
- ascending colon
- transverse colon (right 1/2 to 2/3)
most midgut structures receive what arterial supply?
SMA
what happens to the primary intestinal loop from ~weeks 5-7 of development?
rapid elongation of gut and mesentery
what allows space for midgut rotation during development?
physiological umbilical herniation during week 8
how does the midgut rotate during development?
270 degrees counterclockwise around SMA axis
what happens after midgut rotation during development?
umbilical herniation retraction during week 10
name the structures of the hindgut
- transverse colon (left 1/3 to 1/2
- descending colon
- sigmoid colon
- rectum
- anal canal (sup. portion)
- internal lining of bladder & urethra
during development, the anal canal migrates into the ____
cloacal region
