Development Of Digestive System Flashcards
What is the primitive gut
Part of endoderm-lined yolk sac cavity incorporated into the embryo
3 parts of the primitive gut?
Foregut, midgut and hindgut
Foregut and hindgut are blind ended, what about midgut
Temporarily connected to yolk sac by vitelline duct
Two parts of the foregut
Pharyngeal gut and caudal to pharyngeal gut up to the hepatic diverticulum (so from proximal part of duodenum and up)
Pharyngeal gut (part of foregut) extends from where to where
Oropharyngeal membrane to respiratory diverticulum
Where does midgut begin and end
Caudal to liver bud and extends to junction of proximal and distal transverse colon
Hindgut extends from where to where
Distal transverse colon to cloacal membrane
- What arises from endoderm
2. What arises from visceral (splanchnic) mesoderm
- Epithelial lining of GI tract and glands
2. Muscle, connective tissue, and peritoneal components of wall of gut (and stroma of glands)
Ventral mesentery exists for what 3 organs
Derived from?
Esophagus, stomach, and initial part of duodenum
Septum transversum (mesodermal plate between pericardial cavity and stalk of yolk sac)
Function of tracheoesophageal septum
Completely separates esophagus from respiratory diverticulum
What is esophageal atresia?
What does this cause
Distal esophagus becomes connected to trachea just above bifurcation
Accumulation of excess amniotic fluid (polyhydramnios)
Where does esophageal stenosis usually occur
In lower 1/3
What is a congenital hiatal hernia caused by
Failure of esophagus to lengthen causes stomach to be pulled up through esophageal hiatus of diaphragm
What part of the stomach do both vagus nerves innervate
Right vagus nerve innervates posterior wall of stomach
Left vagus nerve innervates anterior wall of stomach
~left side of stomach becomes anterior side
What creates the omental bursa/lesser peritoneal sac?
Rotation of stomach pulls dorsal mesogastrium to the left and ventral mesogastrium to the right creating a space behind stomach
What causes ventral mesogastrium to divide into 2 regions
What are these regions
Development of liver
Liver to ventral body wall (forms falciform ligament) and stomach to upper duodenum to lover (forms lesser omentum)
Free margin of lesser omentum contains what 3 things
Bile duct, portal vein, and hepatic artery (portal triad)
What causes pyloric stenosis
What does it cause
When musculature of stomach (usually circular fibers) hypertrophies in the pyloric region
Obstructs passage of food resulting in severe vomiting
What part of the gut is the duodenum
Terminal part of foregut and initial part of midgut
Duodenum rotates __
What does this contribute to
To the right with the pancreas
Contributes to these two organs being retroperitoneal (fuse with posterior body wall)