embryo devel GI second set of q

Question 1

rotation of foregut

Answer 1

stomach moves to the left, liver moves to the right

relative size of the two peritoneal cavities changes

right side gets smaller!

Question 2

what part of the doudenum is considered midgut?

Answer 2

duodenum distal to major papilla

Question 3

gut atresias and stensoses: upper duodenum and caudad to the duodenum

Answer 3

upper part usually result of failure to recanalize

distal to duodenum, probably a vascular compromise

Question 4

apple peel atresia

Answer 4

proximal jejunum, intestine is short, and the portion distal to the defect is coiled around the mesenteric remnant

Question 5

a patient comes in with a problem the proximal jejunum and, and low body weight

Answer 5

apple peel atresia

Question 6

@ 6 weeks, the developing fetus shows signs of herniation

Answer 6

this is natural because the midgut is growing rapidly and pushes into the umbilical cord. simultaneously, the gut loop rotates ~90 degrees COUNTERclockwise around the superior mesenteric a.

Question 7

physiological herniation of midgut

Answer 7

is perfectly normal, midgut is growing into umbilical cord while the loop is rotating counterclock wise, 90 degrees

Question 8

Primary intestinal loop: two parts, the cranial end and the caudal end

Answer 8

cranial end becomes the distal duodenum to ileum

caudad end becomes the lower ileum to proximal 2/3 transverse colon

Question 9

rotations of the midgut

Answer 9

at 6 weeks the midgut expands into the umbilical cord and rotates 90 degrees counterclockwise

at 10 weeks, the herniated loop returns to the abdominal activity and rotates an additional 180 degrees (270 degrees total)

Question 10

Malrotation of the midgut

Answer 10

partial rotation only, increases “entrapment” of portions of the intestine.

Question 11

child presents with bilious vomiting within the first week after birth, diarrhea, septic shock, abnormal distention and food intolerance. diagnosis

Answer 11

malrotation

Question 12

Volvulus

Answer 12

volvulus is the abnormal twisting of the intestine which causes an obstruction……compromises intestine or blood flow

usually an axial rotation around a certain part of the intestine and its mesentery

Question 13

Bilious Emesis

Answer 13

may indicate malrotation and volvulus

Question 14

Intussusception

Answer 14

enfolding one segment of intestine within another

Question 15

a patient complains of abdominal pains that become worse and worse, recurring attacking of cramping, and “jelly stools”

Answer 15

intussusception

indicates enfolding of one segment of the intestine within another

Question 16

Ladd’s bands

Answer 16

fibrous stalks of peritoneal tissue that attach to cecum to the abdominal wall and create an obstruction of the duodenum. this condition is found in malrotation of the intestine.

Question 17

Body wall defects

Answer 17

omphoceles, gastroschisis, prune belly syndrome

Question 18

omphaloceles

Answer 18

herniation of abdominal content through enlarged umbilical ring

NORMAL IF temporary

gut should return into abdomen as the embryo grows

Question 19

omphaloceles: cause

Answer 19

midgut fails to return to abdominal cavity

pale, shiny sac protrudes from base of umbilical core

Question 20

Gastroschisis

Answer 20

failure of the anterior abdominal wall musculature to close during folding. the gut is not surrounded by a membrane

survival rate excellent

this is distinguished from the omphalocele because it is not occuring through the umbilical cord

Question 21

prune belly

Answer 21

Eagle-Barrett syndrome

triad: anterior abdominal wall musculature is deficient or absent
urinary tract anomalies
bilateral cryptorchidism

occurs almost exclusively in males

BLADDER, ABDOMINAL WALL, KIDNEY, UNDESCENDED TESTES

Question 22

PBS Etiology: 2 hypothesis

Answer 22

Urinary tract obstruction as the result of a prostate hyoplastic or dysplastic tract obstruction, leadings to overdistension of the bladder and the upper urinary tract. streched abdominal wall. causes damage to abdominal musculature

primary medosermal development defect. insult between 6-10 wks, disrupts intermediate lateral plate mesoderm which gives rise to both abdominal musculature and the prostate

Question 23

Ileal diverticulum

Answer 23

meckel’s diverticulum
remnant of vitelline duct
asymptomatic
gastric/pancreatic tissue inside

Question 24

failure of the vitelline duct to close

rule of 2’s

Answer 24

2% prevalence
2:1 female predominance
2 feet from ileocecal valve in adults, location
half of patients who are symptomatic are younger than 2 years of age

Question 25

symptoms of the ileal diverticulum if fistula is present

Answer 25

fistula present

decal discharge through umbilicus

Question 26

a guy is shitting through his umbilicus

Answer 26

ileal diverticulum with fistula present

Question 27

Hirschsprung’s disease

Answer 27

congenital aganglionic megacolon
a motor disorder of the colon causing functional intestinal obstruction

failure of neural crest cells to migrate and establish colonic ganglions

no parasympathetic innervation. no peristalsis, or no relaxation, results in a functional obstruction

Question 28

if hirschsprung’s is identified, where would it be most lethal? what is the treatment

Answer 28

in the proximal parts of the intestine/colon

surgery: aganglionic part removed, ganglionic part connected to colon/rectum

Question 29

what does “rotation” of the gut do generally? name four things

Answer 29

1) reduces space
2) changes organ relationships
3) causes changes of some of the dorsal mesenteries
4) structures will be primarily or secondarily retroperitoneal

Question 30

left peritoneal diverticulum —>

Answer 30

greater sac

Question 31

right peritoneal diverticulum –>

Answer 31

lesser sac

Question 32

partitioning of the cloaca

Answer 32

develops from the hindgut of the endoderm

cloaca divided by urorectal septum into urogenital sinus and rectum

Question 33

defects in cloaca partitioning

failure of folds to develop

Answer 33

rectourethral fistula

Question 34

defects in cloaca partitioning

failure of folds to develop in men

Answer 34

rectoprostatic fistula

Question 35

defects in cloaca partitioning

failure of folds to develop in women (2)

Answer 35

rectocloacal canal

rectovaginal fistula

Question 36

what three defects can occur during cloacal partitioning?

Answer 36

rectovaginal fistula
rectoprostatic fistula
rectocloacal canal

Question 37

malalignment of folds

Answer 37

rectourethral fistula involving rathke fold

tourneux fold

Question 38

anorectal malformations

Answer 38

occurs when the rectum ends in a blind pouch and does not connect with the external environment

stenosis, or narrowing of the anus, or absence of the anus may be present

Question 39

Anorectal malformations

Answer 39

spectrum of defects with “high” and “low” species

anal membrane fails to perforate
anal canal ends as blind sac below pelvic diaphragm (anal agenesis)
rectum ends as blind pouch above the pelvic diaphragm (anorectal agenesis, most common)

Question 40

anal canal ends as a blind pouch BELOW pelvic diaphragm

Answer 40

anal agenesis

Question 41

anal canal ends as blind pouch ABOVE pelvic diaphragm

Answer 41

anorectal agenesis, most common

Question 42

imperforate anus symptoms and signs

Answer 42

absence of misplacement of anus
anus opens near vagina
anus opens into the vagina, penis, scrotum, urethra 
no passage of stool in 24-48 hrs 
abdominal distention

Question 43

high anorectal malformations

Answer 43

these are the ones with the “bad” prognosis, since there are no pelvic muscles that can compensate for passing stool

high rectovaginal fistula

rectobladderneck fistula

Question 44

low anorectal malformations

Answer 44

these are the “good” ones because other muscles can be trained to help pass stool

vestibular fistula
rectourethral bulbar fistula

Question 45

Clinical prognosis: imperforate anus

Answer 45

a colostomy is indicated after birth, with surgical correction prognosis is excellent

Question 46

Rectourethral fistula

Answer 46

colostomy before repair period. long term prog. for normal urethral and rectal function is good

Question 47

rectovesical fistula

Answer 47

usually also have poorly developed sacral bones and sphincters. prognosis for normal bowel function is poor.