Embryo

Question 1

What is an annular pancreas?

Answer 1

Where the duodenum is obstructed (remember drawing). If stenosis is below bile duct, then vomit is bilious.

2/3 of patients = asymptomatic

Question 2

What is omphalocele? What week does this happen?

Answer 2

When the bowel does not return to the body cavity.

Week 10

*NOT and umbilical hernia*

Question 3

What does the septum transversum become?

Answer 3

central tendon

Question 4

What week does the tracheoesophageal fistula form?

Answer 4

Week 5

Question 5

At what week does the bile duct form?

Answer 5

12 weeks

Question 7

What comes from endoderm?

Answer 7

Epithelium

Question 8

The pancreas head comes from what?

Answer 8

Ventral primordia

Question 9

What cells make up the mesoderm of the liver?

Answer 9

Stroma + cutler cells + hematopoietic cells

Question 10

What does the mesentery give rise to?

Answer 10

Double layer of peritoneum (visceral layer)

Question 11

What is the blood supply, nerves, and lymph for superior from hindgut of anal canal?

Answer 11

Inferior Mesenteric A.

Autonomic N.S.

Inferior Mesenteric L.N.’s

Question 12

Describe midgut rotation (where intestines go out and then come back in).

At what weeks does this happen? Total rotation?

Answer 12

Out @ 6 weeks

In @ 10 weeks

Rotates 90 degrees while in umbilical cord, then 180 degrees when it comes back

Total 260 degrees rotation

Question 13

What comes from ectoderm?

Answer 13

mouth + anal canal

Question 14

What does the ventral mesentery form?

Answer 14

Falciform L.

Question 15

How many layers does the greater omentum (apron) have?

Answer 15

4

Question 16

What does the dorsal mesentery of the esophagus (crura) become for diaphragm?

Answer 16

Right/left crus of diaphragm

Question 17

How would you get an anorectal malformation?

Answer 17

If endoderm (top of anus) + ectoderm (actual hole @ bottom) do not meet at the right place!

Question 18

What week does the stomach form?

Answer 18

week 4

Question 19

What comes from NC?

Answer 19

Autonomic ganglion

Question 20

What cells is the liver made of?

Answer 20

Endoderm (most organs)

Question 21

What is the blood supply of the hindgut?

Answer 21

Inferior mesenteric A.

Question 22

What does the parietal layer give rise to?

Answer 22

Lines body wall (somatic layer)

Question 23

What is Hirschsprung Disease? Embryological Mechanism?

Answer 23

“mega colon”

Neural Crest Cell Problem

Absence of Autonomic Ganglia cells where constricted (so feces builds up behind it where bowel is still contracting)

Question 24

What comes from the foregut?

Answer 24

*All structures below diaphragm*

esophagus, stomach, liver, pancreas, proximal duodenum

Question 25

What is the blood supply of the foregut?

Answer 25

Celiac trunk A.

Question 26

What does the dorsal mesogasrium form?

Answer 26

Greater omentum Splenorenal L. Gastroleinal L. \*stomach --\> posterior body wall\*

Question 27

What is congenital diaphragmatic hernia?

Answer 27

Herniation into the thoracic cavity due to the failure of components of the diaphragm to fuse properly

Question 28

What weeks does the spleen help with hematopoiesis?

Answer 28

Weeks 9-28

Question 29

What is the blood supply of the midgut?

Answer 29

Superior mesenteric A. It is the axis (herniating to umbilical cord)

Question 30

The cloacal membrane includes the urogenital membrane and the anal membrane. What do these become? What germ layer are they made out of?

Answer 30

Bladder + urethra Anus Endo + Ectoderm (want them to rupture)

Question 31

What is Meckel's Diverticulum?

Answer 31

The vitelline duct (ileum to abdominal wall) does not regress, and therefore feces comes out of the belly button. ## Footnote **Rule of 2's**

Question 32

At what week is the spleen formed? What germ layer is it?

Answer 32

Week 5 Mesoderm

Question 33

What comes from midgut?

Answer 33

small intestine, cecum, appendix, colon (transverse)

Question 34

The cloaca becomes what?

Answer 34

Anus

Question 35

What is a congenital diaphragmatic hernia?

Answer 35

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-

Question 36

What comes from mesoderm?

Answer 36

Splanchnic Mesoderm (smooth M.)

Question 37

What ventral outgrowth forms the liver + gallbladder?

Answer 37

Hepatic diverticulum

Question 38

What is the blood supply, nerves, and lymph for inferior from proctodeum of anal canal?

Answer 38

Middle + Inferior Rectal Pudendal (somatic N.) \*voluntary control\* Superficial Inhuinal L.N.'s

Question 39

The pancreas body comes from what?

Answer 39

Dorsal primordia

Question 40

What is hypertrophic pyloric stenosis? What plane does it happen at?

Answer 40

Where muscles of the pylorus hypertrophy (knot @ bottom of stomach) and food has nowhere to go ---\> "projectile vomiting" Happens at L1: Transpyloric plane

Question 41

What does the ventral mesogastrium form?

Answer 41

Lesser omentum \*stomach --\> liver\*

Question 42

Where does a congenital inguinal hernia appear?

Answer 42

Indirect (deep ring) Trapping/Constricting of intestines

Question 43

What comes from hindgut?

Answer 43

Rest of colon, rectum, anal canal, bladder, urethra

Question 44

Striated muscle comes from...?

Answer 44

Pharyngeal arches 4+6

Question 45

What is the mesentery made out of?

Answer 45

Double layer of splanchnic mesoderm. It allows blood vessels + nerves to reach the organs Dorsal = posterior Ventral = anterior

Question 46

What is gastroschisis? At what week does this happen?

Answer 46

When the body wall does not close (no sac). Herniation of abdominal contents due to muscular defect in abdominal wall. Week 4

Question 47

What is a tracheoesophageal fistula?

Answer 47

Trachea + Esophagus fuse Coiling NG tube = diagnosis Polyhydramnios

Question 48

The main pacreatic duct comes from what?

Answer 48

Ventral pancreatic duct