development of GI

Question 1

etiology of congenital umbilical hernia

Answer 1

incomplete closure of umbilical ring via abdominal wall musculature and fascia

Question 2

when will a congenital umbilical hernia be most noticeable in infants?

Answer 2

when they are crying due to increased abdominal pressure

Question 3

endoderm forms

Answer 3

forms epithelial lining and glands of GI mucosa, hepatocytes, pancreas

Question 4

splanchnic mesoderm forms

Answer 4

all other components of GI layers, liver and biliary apparatus, pancreas connective tissue, spleen

Question 5

neural crest cells form

Answer 5

enteric nervous sytem

Question 6

Hirschsprung disease

Answer 6

aganglionic distal intestine leading to chronic constipation and obstruction

Question 7

gut tube at week 4 is connected to

Answer 7

umbilical vesicle at omphaloenteric duct

Question 8

at week 4, the gut tube is suspended by what

Answer 8

ventral and dorsal mesentery

Question 9

movement of the foregut

Answer 9

rotates 90º toward the left side of body in week 6 (right hand movement)

Question 10

movement of the midgut and proximal hindgut

Answer 10

rotates 270º toward the right side of the body on superior mesenteric artery axis

Question 11

formation of stomach

Answer 11

dilation forms in superior foregut and the dorsal border grows larger than the ventral border
week 6, stomach rotates 90º to left and tilts slightly

Question 12

dorsal border of developing stomach becomes

Answer 12

greater curvature of the stomach

Question 13

ventral border of developing stomach becomes

Answer 13

lesser curvature of the stomach

Question 14

formation of duodenum

Answer 14

a C-shaped loop forms distal to the stomach; when it is in its final position it adheres to the body wall

Question 15

endoderm proliferates in the caudal stomach to from

Answer 15

pyloric sphincter

Question 16

formation of liver & biliary apparatus

Answer 16

hepatic diverticulum splits into a cranial and caudal bud and these organs are pulled to the right side of the body due to stomach rotation

Question 17

hepatic diverticulum protrudes where

Answer 17

ventrally from the inferior foregut, extending into the septum transverse and ventral mesentery

Question 18

cranial bud becomes

Answer 18

liver

Question 19

caudal bud becomes

Answer 19

gallbladder

Question 20

hepatic stalk becomes

Answer 20

biliary apparatus

Question 21

formation of the pancreas

Answer 21

dorsal pancreatic bud protrudes in the distal foregut, ventral pancreatic bud protrudes in the hepatic stalk; pancreatic buds fuse together and part of it fuses to the body wall

Question 22

why is the ventral pancreatic bud pulled to the right?

Answer 22

stomach rotation

Question 23

dorsal pancreatic bud becomes

Answer 23

head, neck, body, tail

Question 24

ventral pancreatic bud becomes

Answer 24

uncinate process

Question 25

insulin secretion starts when

Answer 25

week 10 (important because insulin cannot cross the placenta!)

Question 26

development of spleen

Answer 26

Question 27

due to stomach rotation, right CN X becomes

Answer 27

posterior vagal trunk

Question 28

due to stomach rotation, left CN X becomes

Answer 28

anterior vagal trunk

Question 29

ventral mesentery becomes

Answer 29

lesser omentum, falciform ligament, coronary ligament of liver

Question 30

dorsal mesentery becomes

Answer 30

greater omentum, mesentery proper

Question 31

umbilical herniation

Answer 31

normal herniation in which the developing intestines protrude via a midgut loop into the umbilical vesicle

Question 32

midgut formation

Answer 32

midgut loop elongates ventrally with two limbs, rotates 90º to the right at week 6 and another 180º at week 10

Question 33

cranial limb becomes

Answer 33

small intestines and forms intestinal loops

Question 34

caudal limb becomes

Answer 34

large intestines

Question 35

cranial limb moves which way at week 6

Answer 35

right

Question 36

caudal limb moves which way at week 6

Answer 36

left

Question 37

cecal diverticulum

Answer 37

forms an anti-mesenteric border of caudal limb

Question 38

which way does the appendix extend

Answer 38

retrocecal

Question 39

what parts of the LI are secondarily retroperitoneal

Answer 39

ascending and descending colon

Question 40

cloaca

Answer 40

expanded terminal hindgut that connects to allantois

Question 41

partitioning the cloaca

Answer 41

Question 42

most organs are

Answer 42

intraperitoneal

Question 43

the exceptions to this rule: primarily retroperitoneal

Answer 43

the very beginning and end of the GI tract are fixed points

Question 44

the exceptions to this rule: secondarily retroperitoneal

Answer 44

duodenum, pancreas (except tail), bare area of liver, ascending colon, descending colon

Question 45

sex independent inguinal canal development

Answer 45

gonads start to develop, gubernaculum connects caudal pole of gonads to labioscrotal folds, peritoneum along gubernaculum evaginates to form processes vaginalis, a temporary tube

Question 46

female specific inguinal canal development

Answer 46

ovaries descend into pelvis, gubernaculum becomes ovarian ligament and round ligament of uterus

Question 47

male specific inguinal canal development

Answer 47

testes descends through pelvis, inguinal canal, into scrotum; gubernaculum becomes scrotal ligament

Question 48

ileal diverticulum

Answer 48

remnant of the omphaloenteric duct; rule of 2

Question 49

hypertrophic pyloric stenosis

Answer 49

distended abdomen, projectile non-bilious vomiting

Question 50

duodenal stenosis and atresia

Answer 50

narrowing of duodenum due to failure of duodenum to recanalize in week 8; vomit may contain bile

Question 51

annular pancreas

Answer 51

bifid ventral pancreatic bud or failure to fully rotate duodenum

Question 52

congenital omphalocele

Answer 52

herniated organs covered by peritoneum and amnion; caused by failure of physiological umbilical herniation to reduce

Question 53

anorectal malformations

Answer 53

incorrect partitioning of cloaca, could be a presence of a fistula or connection between urethra and rectum