embryo devel GI second set of q Flashcards Preview

COM Anatomy, Biochemistry, OS > embryo devel GI second set of q > Flashcards

Flashcards in embryo devel GI second set of q Deck (47):
1

rotation of foregut

stomach moves to the left, liver moves to the right

relative size of the two peritoneal cavities changes

right side gets smaller!

2

what part of the doudenum is considered midgut?

duodenum distal to major papilla

3

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

upper part usually result of failure to recanalize
distal to duodenum, probably a vascular compromise

4

apple peel atresia

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

5

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

apple peel atresia

6

@ 6 weeks, the developing fetus shows signs of herniation

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.

7

physiological herniation of midgut

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

8

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

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

9

rotations of the midgut

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)

10

Malrotation of the midgut

partial rotation only, increases "entrapment" of portions of the intestine.

11

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

malrotation

12

Volvulus

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

13

Bilious Emesis

may indicate malrotation and volvulus

14

Intussusception

enfolding one segment of intestine within another

15

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

intussusception

indicates enfolding of one segment of the intestine within another

16

Ladd's bands

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.

17

Body wall defects

omphoceles, gastroschisis, prune belly syndrome

18

omphaloceles

herniation of abdominal content through enlarged umbilical ring

NORMAL IF temporary

gut should return into abdomen as the embryo grows

19

omphaloceles: cause

midgut fails to return to abdominal cavity

pale, shiny sac protrudes from base of umbilical core

20

Gastroschisis

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

21

prune belly

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

22

PBS Etiology: 2 hypothesis

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

23

Ileal diverticulum

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

24

failure of the vitelline duct to close
rule of 2's

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

25

symptoms of the ileal diverticulum if fistula is present

fistula present
decal discharge through umbilicus

26

a guy is shitting through his umbilicus

ileal diverticulum with fistula present

27

Hirschsprung's disease

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

28

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

in the proximal parts of the intestine/colon

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

29

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

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

30

left peritoneal diverticulum --->

greater sac

31

right peritoneal diverticulum -->

lesser sac

32

partitioning of the cloaca

develops from the hindgut of the endoderm
cloaca divided by urorectal septum into urogenital sinus and rectum

33

defects in cloaca partitioning

failure of folds to develop

rectourethral fistula

34

defects in cloaca partitioning

failure of folds to develop in men

rectoprostatic fistula

35

defects in cloaca partitioning

failure of folds to develop in women (2)

rectocloacal canal
rectovaginal fistula

36

what three defects can occur during cloacal partitioning?

rectovaginal fistula
rectoprostatic fistula
rectocloacal canal

37

malalignment of folds

rectourethral fistula involving rathke fold
tourneux fold

38

anorectal malformations

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

39

Anorectal malformations

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)

40

anal canal ends as a blind pouch BELOW pelvic diaphragm

anal agenesis

41

anal canal ends as blind pouch ABOVE pelvic diaphragm

anorectal agenesis, most common

42

imperforate anus symptoms and signs

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

43

high anorectal malformations

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

44

low anorectal malformations

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

vestibular fistula
rectourethral bulbar fistula

45

Clinical prognosis: imperforate anus

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

46

Rectourethral fistula

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

47

rectovesical fistula

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