Embryo Flashcards
What is an annular pancreas?
Where the duodenum is obstructed (remember drawing). If stenosis is below bile duct, then vomit is bilious.
2/3 of patients = asymptomatic
What is omphalocele? What week does this happen?
When the bowel does not return to the body cavity.
Week 10
*NOT and umbilical hernia*
What does the septum transversum become?
central tendon
What week does the tracheoesophageal fistula form?
Week 5
At what week does the bile duct form?
12 weeks
What comes from endoderm?
Epithelium
The pancreas head comes from what?
Ventral primordia
What cells make up the mesoderm of the liver?
Stroma + cutler cells + hematopoietic cells
What does the mesentery give rise to?
Double layer of peritoneum (visceral layer)
What is the blood supply, nerves, and lymph for superior from hindgut of anal canal?
Inferior Mesenteric A.
Autonomic N.S.
Inferior Mesenteric L.N.’s
Describe midgut rotation (where intestines go out and then come back in).
At what weeks does this happen? Total rotation?
Out @ 6 weeks
In @ 10 weeks
Rotates 90 degrees while in umbilical cord, then 180 degrees when it comes back
Total 260 degrees rotation
What comes from ectoderm?
mouth + anal canal
What does the ventral mesentery form?
Falciform L.
How many layers does the greater omentum (apron) have?
4
What does the dorsal mesentery of the esophagus (crura) become for diaphragm?
Right/left crus of diaphragm
How would you get an anorectal malformation?
If endoderm (top of anus) + ectoderm (actual hole @ bottom) do not meet at the right place!
What week does the stomach form?
week 4
What comes from NC?
Autonomic ganglion
What cells is the liver made of?
Endoderm (most organs)
What is the blood supply of the hindgut?
Inferior mesenteric A.
What does the parietal layer give rise to?
Lines body wall (somatic layer)
What is Hirschsprung Disease? Embryological Mechanism?
“mega colon”
Neural Crest Cell Problem
Absence of Autonomic Ganglia cells where constricted (so feces builds up behind it where bowel is still contracting)
What comes from the foregut?
*All structures below diaphragm*
esophagus, stomach, liver, pancreas, proximal duodenum
What is the blood supply of the foregut?
Celiac trunk A.
What does the dorsal mesogasrium form?
Greater omentum
Splenorenal L.
Gastroleinal L.
*stomach –> posterior body wall*
What is congenital diaphragmatic hernia?
Herniation into the thoracic cavity due to the failure of components of the diaphragm to fuse properly
What weeks does the spleen help with hematopoiesis?
Weeks 9-28
What is the blood supply of the midgut?
Superior mesenteric A.
It is the axis (herniating to umbilical cord)
The cloacal membrane includes the urogenital membrane and the anal membrane. What do these become? What germ layer are they made out of?
Bladder + urethra
Anus
Endo + Ectoderm (want them to rupture)
What is Meckel’s Diverticulum?
The vitelline duct (ileum to abdominal wall) does not regress, and therefore feces comes out of the belly button.
Rule of 2’s
At what week is the spleen formed? What germ layer is it?
Week 5
Mesoderm
What comes from midgut?
small intestine, cecum, appendix, colon (transverse)
The cloaca becomes what?
Anus
What is a congenital diaphragmatic hernia?
Where the intestines get pushed up into the thorax!!
Defective fusion/formation of the pleuroperitoneal membranes (large opening in diaphragm)
Most occur on LEFT side
-Herniation of abdominal contents, hypoplastic lungs, polyhydraminos-
What comes from mesoderm?
Splanchnic Mesoderm (smooth M.)
What ventral outgrowth forms the liver + gallbladder?
Hepatic diverticulum
What is the blood supply, nerves, and lymph for inferior from proctodeum of anal canal?
Middle + Inferior Rectal
Pudendal (somatic N.) *voluntary control*
Superficial Inhuinal L.N.’s
The pancreas body comes from what?
Dorsal primordia
What is hypertrophic pyloric stenosis? What plane does it happen at?
Where muscles of the pylorus hypertrophy (knot @ bottom of stomach) and food has nowhere to go —> “projectile vomiting”
Happens at L1: Transpyloric plane
What does the ventral mesogastrium form?
Lesser omentum
*stomach –> liver*
Where does a congenital inguinal hernia appear?
Indirect (deep ring)
Trapping/Constricting of intestines
What comes from hindgut?
Rest of colon, rectum, anal canal, bladder, urethra
Striated muscle comes from…?
Pharyngeal arches 4+6
What is the mesentery made out of?
Double layer of splanchnic mesoderm. It allows blood vessels + nerves to reach the organs
Dorsal = posterior
Ventral = anterior
What is gastroschisis? At what week does this happen?
When the body wall does not close (no sac). Herniation of abdominal contents due to muscular defect in abdominal wall.
Week 4
What is a tracheoesophageal fistula?
Trachea + Esophagus fuse
Coiling NG tube = diagnosis
Polyhydramnios
The main pacreatic duct comes from what?
Ventral pancreatic duct
