Embryology Flashcards
Endodermal derivatives of gut tube
epithelium and glands
Mesodermal derivatives of gut tube
connective tissue and muscle of gut
Blood supply to foregut
Celiac artery
Blood supply to midgut
superior mesenteric artery
Blood supply to hindgut
inferior mesenteric artery
Innervation of foregut
Vagus nerve
Innervation of midgut
Vagus nerve
Innervation of hindgut
pelvic splanchnic nerves from S2,S3, and S4
Adult derivatives of the foregut
pharynx, lower respiratory system, esophagus, stomach, superior half of duodenum, liver, biliary system, and pancreas
Innervation of ventral wall of stomach
left vagus nerve
Innervation of dorsal wall of stomach
right vagus nerve
Which wall of the stomach grows faster?
The dorsal stomach wall grows faster than the ventral wall, resulting in greater and lesser curvatures of the stomach
What does the dorsal mesogastrium form in the adult
Greater momentum, gastrosplenic, and splenorenal ligaments in the adult
How is the omental bursa formed
From rotation of the dorsal mesogastrium. It is located dorsal to the stomach
epiploic foramen
Communication between lesser and greater sac
Ventral mesogastrium
Becomes the lesser omentum in the adult
What two structures form the duodenum
Caudal foregut and cranial midgut
Where does the attachment of the bile duct occur?
Just proximal to the junction of the foregut and midgut duodenal segments
Effects of rotation of the stomach
Secondary retroperitoneal placement of pancreas, formation of omental bursa, stretching of dorsal mesogastrium, rotates duodenal loop to the right pushing pancreas and duodenum into a secondarily retroperitoneal position.
Effect of duodenal rotation
Carries ventral pancreatic bud posterior to the dorsal bud and they fuse, pancreas becomes secondarily retroperitoneal
Ventral pancreatic bud
Becomes part of pancreatic head, uncinate process, and most of main pancreatic duct
Dorsal pancreatic bud
Forms everything the ventral bud doesn’t
Hepatic Diverticulum
Divides into cranial portion that forms the liver, and caudal portion that forms the gallbladder and cystic duct
Ventral mesentery
most of it regresses, but also gives rise to lesser omentum, falciform ligament, and its visceral peritoneum
Midgut derivatives
Most of small intestine, cecum and vermiform appendix, ascending colon, right half of transverse colon
Cranial limb of midgut loop
Forms jejunum and upper ileum
Caudal limb of midgut
lower ileum, ascending colon and proximal 1/2 of transverse colon
Cecal Diverticulum
appears on caudal limb of midgut and develops into cecum and vermiform appendix
Anomalies of midgut structures
Malrotations of midgut, congenital omphalocele, umbilical hernia, gastroschisis, ileal (Meckel’s) diverticulum
Cranial hindgut
Forms distal 1/2 of transverse colon, descending and sigmoid colon
Terminal end of hindgut
Cloaca, which forms rectum and superior anal canal
What is the spleen derived from specifically?
The mesenchymal cells between the layers of the dorsal mesogastrium
