Development of the Abdomen Flashcards Preview

S&F IV: Exam One > Development of the Abdomen > Flashcards

Flashcards in Development of the Abdomen Deck (16):

Esophagus Formation

The respiratory diverticulum expands to form the esophagotracheal ridge which will grow inward separating the pharynx into two longitudinal tubes


Stomach Development

Begins as a dilation in the gut tube and the dorsal surface will grow fast and rotate 90 degrees clockwise making the greater curvature end up on the left

*This rotation leads to the formation of the lesser sac


Vagal Trunk Composition

Anterior is primarily left and posterior to stomach is primarily right

*Due to rotation of the stomach during development


Liver development

Begins as the hepatic diverticulum off the gut tube and pushes into the septum transversum becoming suspended in the foregut and anterior abdominal wall

*Septum transversum pulled along during development becomes the ventral mesentary


Falciform ligament

Liver to anterior abdominal wall

*Carries the abdominal vein


Central tendon of the diaphragm

Derived from the septum transversum and is in direct contact w/ the bare area of the liver


Gall Bladder development

Arises from the hepatic diverticulum; common stalk of the liver connected to the gall bladder and ventral pancreas becomes the common bile duct


Pancreas Development

Ventral pancreas arises from hepatic diverticulum and dorsal develops of the duodenum

=> Fuse in week 6; ventral bud becomes main pancreatic duct and dorsal bud becomes accessory duct

*Growth of the dorsal duodenal wall pushes the ventral pancreas and bile duct dorsally


Annular Pancreas

Congenital abnormality characterized by a ring of pancreatic tissue from the ventral bud surrounding the duodenum

*Causes intestinal obstruction


Spleen Developent

Independent condensation of mesoderm b/w the dorsal mesentary of the stomach



Ventral body wall defect causing herniation of the intestinal loops into the amniotic cavity

*Failure of body wall to close; viscera are NOT covered in peritoneum



Ventral wall defect caused by failure of the intestines to return to the abdominal cavity after physiological umbilical herniation

*Intestines are covered by peritoneum


Midgut Development

During physiological umbilical herniation, the intestines rotate 90 degrees counterclockwise around the superior mesenteric artery; when the return to the abdomen, they rotate another 180 degrees and the proximal end enters the upper left part of the abdominal cavity

*Cecum forms as swelling on the caudal loop during this timeframe (4-10 weeks)


Hindgut development

The urogenital septum grows b/w the hindgut and allantois dividing the cloaca into the urogenital sinus and the anorectal canal

=> The proctodeum will push inward on the anorectal canal to form the distal opening of the tube


Pectinate Line

Separation b/w regions of the anal canal formed by the cloaca and the proctodeum `


Innervation and Blood Supply to the anal canal

Superior to Pectinate Canal: Blood- Inferior Mesenteric Arteries
Nerves- Autonomic

Inferior to Pectinate Canal: Blood- Internal Iliac Artery
Nerves: Spinal nerves