Development of Body Cavities/Digestive System Flashcards
what is a congenital pericardial defect?
- defective formation/fusion of pleuropericardial membranes
- left atrium can herniate into pleural cavity
what is posterolateral defect of diaphragm?
- fusion of pleuroperitoneal membrane with mesoesophagus & septum transversum
- associated with congenital diaphragmatic hernia
- also called foramen of Bochdalek
what can congenital diaphragmatic hernia cause?
- life threatening breathing difficulties
- delay of lung maturation
- polyhydramnios (excess amniotic fluid)
- most common cause of pulmonary hypoplasia
what is eventration of the diaphragm?
half the diaphragm is defective and invades thoracic cavity as aponeurotic sheet & abdominal viscera displace superiorly
what is gastroschisis?
congenital fissure in anterior abdominal wall & protrusion of viscera in median plane between xiphoid process and umbilicus
how does gastroschisis occur?
- failure of lateral body folds to fuse when forming the anterior abdominal wall
- small intestine herniates into amniotic cavity
what is congenital hiatal hernia?
herniation of part of fetal stomach through excessively large esophageal hiatus
what is a retrosternal (parasternal) hernia?
- hernia through sternocostal hiatus (foramen of Morgagni) which is also the opening for superior epigastric vessels
- hiatus located between sternal & costal parts of diaphragm
accessory diaphragm
- often on right side
- associated with lung hypoplasia
- treated with surgical excision
what’s the most common cause of esophageal atresia?
tracheoesophageal fistula
what is a major symptom of esophageal atresia?
infant can’t swallow –> polyhydramnios
what causes esophageal stenosis?
incomplete recanalization of esophagus or failure of esophageal blood vessels to develop
what is hypertrophic pyloric stenosis?
muscular thickening of pylorus causing projectile vomiting and obstruction of the passage of food
how do you treat hypertrophic pyloric stenosis?
pyloromyotomy (surgical relief of pyloric obstruction)
what is duodenal stenosis?
partial occlusion of duodenal lumen & usually vomiting occurs
where does a duodenal atresia usually occur?
hepatopancreatic ampulla
what is bilious emesis?
vomiting of bile
what is the most common form of extrahepatic biliary atresia?
obliteration of the bile ducts —> jaundice
what can an ectopic pancreas indicate?
internal bleeding, obstruction, or cancer
why is an annular pancreas important?
it can obstruct duodenum from pancreatitis and can be fixed with surgery
what is polysplenia?
accessory spleens that can be isolated or connected with main spleen and can be fully functional
what is a congenital omphalocele?
herniation of abdominal viscera into proximal umbilical cord
why does an omphalocele occur?
impaired growth of mesodermal and ectodermal components of abdominal wall
how is an umbilical hernia different than an omphalocele?
umbilical hernias are covered by subQ and skin
what is gastroschisis?
extrusion of abdominal viscera outside of umbilical cord
what is malrotation of the gut?
incomplete rotation or fixation of the intestines
what is nonrotation of the gut?
failure of the gut to rotate as it reenters the abdomen
nonrotation of the gut results in?
- small intestine on the right side, large intestine on the left side
- cecum lies inferior to pylorus
- duodenal obstruction
what is midgut volvulus?
twisting of the intestines because they aren’t fixed to the posterior abdominal wall
what does midgut volvulus cause?
- obstruction of superior mesenteric artery
- infarction & gangrene
- bilious emesis (bile vomiting)
reversed rotation of the gut results in?
clockwise rotation:
- duodenum anterior to SMA
- transverse colon posterior to SMA
what is subhepatic cecum and appendix?
cecum adheres to liver upon its return to the abdomen; small liver; appendix higher than normal
a mobile cecum can cause?
- right inguinal hernia
- abnormal location of appendix
- volvulus
atresia or stenosis of intestine occurs from?
abnormal recanalization of intestine during development
inflammation of an ileal diverticulum mimics the symptoms of?
appendicitis
an ileal diverticulum is a remnant of?
proximal omphaloenteric duct (has pancreatic and gastric tissues)
congenital megacolon (Hirschsprung’s disease) causes?
- absence of ANS ganglion in myenteric plexus distal to megacolon
- prevents movement of stool
- mostly in rectum and sigmoid colon
what causes Hirschsprung’s disease?
failure of neural crest cells to migrate into wall of colon
what is an imperforate anus?
- blind end of anal canal
- an ectopic anus
- anoperineal fistula (vagina or urethra)
what is the most common type of anorectal birth defect?
blind end of rectum (anorectal agenesis) with or without fistula to vagina, bladder, or urethra
what causes anorectal agenesis?
incomplete separation of cloaca from UG sinus by urorectal septum
