Development of Body Cavities/Digestive System

Question 1

what is a congenital pericardial defect?

Answer 1

• defective formation/fusion of pleuropericardial membranes

- left atrium can herniate into pleural cavity

Question 2

what is posterolateral defect of diaphragm?

Answer 2

• fusion of pleuroperitoneal membrane with mesoesophagus & septum transversum
• associated with congenital diaphragmatic hernia
• also called foramen of Bochdalek

Question 3

what can congenital diaphragmatic hernia cause?

Answer 3

• life threatening breathing difficulties
• delay of lung maturation
• polyhydramnios (excess amniotic fluid)
• most common cause of pulmonary hypoplasia

Question 4

what is eventration of the diaphragm?

Answer 4

half the diaphragm is defective and invades thoracic cavity as aponeurotic sheet & abdominal viscera displace superiorly

Question 5

what is gastroschisis?

Answer 5

congenital fissure in anterior abdominal wall & protrusion of viscera in median plane between xiphoid process and umbilicus

Question 6

how does gastroschisis occur?

Answer 6

• failure of lateral body folds to fuse when forming the anterior abdominal wall
• small intestine herniates into amniotic cavity

Question 7

what is congenital hiatal hernia?

Answer 7

herniation of part of fetal stomach through excessively large esophageal hiatus

Question 8

what is a retrosternal (parasternal) hernia?

Answer 8

• hernia through sternocostal hiatus (foramen of Morgagni) which is also the opening for superior epigastric vessels
• hiatus located between sternal & costal parts of diaphragm

Question 9

accessory diaphragm

Answer 9

• often on right side
• associated with lung hypoplasia
• treated with surgical excision

Question 10

what’s the most common cause of esophageal atresia?

Answer 10

tracheoesophageal fistula

Question 11

what is a major symptom of esophageal atresia?

Answer 11

infant can’t swallow –> polyhydramnios

Question 12

what causes esophageal stenosis?

Answer 12

incomplete recanalization of esophagus or failure of esophageal blood vessels to develop

Question 13

what is hypertrophic pyloric stenosis?

Answer 13

muscular thickening of pylorus causing projectile vomiting and obstruction of the passage of food

Question 14

how do you treat hypertrophic pyloric stenosis?

Answer 14

pyloromyotomy (surgical relief of pyloric obstruction)

Question 15

what is duodenal stenosis?

Answer 15

partial occlusion of duodenal lumen & usually vomiting occurs

Question 16

where does a duodenal atresia usually occur?

Answer 16

hepatopancreatic ampulla

Question 17

what is bilious emesis?

Answer 17

vomiting of bile

Question 18

what is the most common form of extrahepatic biliary atresia?

Answer 18

obliteration of the bile ducts —> jaundice

Question 19

what can an ectopic pancreas indicate?

Answer 19

internal bleeding, obstruction, or cancer

Question 20

why is an annular pancreas important?

Answer 20

it can obstruct duodenum from pancreatitis and can be fixed with surgery

Question 21

what is polysplenia?

Answer 21

accessory spleens that can be isolated or connected with main spleen and can be fully functional

Question 22

what is a congenital omphalocele?

Answer 22

herniation of abdominal viscera into proximal umbilical cord

Question 23

why does an omphalocele occur?

Answer 23

impaired growth of mesodermal and ectodermal components of abdominal wall

Question 24

how is an umbilical hernia different than an omphalocele?

Answer 24

umbilical hernias are covered by subQ and skin

Question 25

what is gastroschisis?

Answer 25

extrusion of abdominal viscera outside of umbilical cord

Question 26

what is malrotation of the gut?

Answer 26

incomplete rotation or fixation of the intestines

Question 27

what is nonrotation of the gut?

Answer 27

failure of the gut to rotate as it reenters the abdomen

Question 28

nonrotation of the gut results in?

Answer 28

• small intestine on the right side, large intestine on the left side
• cecum lies inferior to pylorus
• duodenal obstruction

Question 29

what is midgut volvulus?

Answer 29

twisting of the intestines because they aren’t fixed to the posterior abdominal wall

Question 30

what does midgut volvulus cause?

Answer 30

• obstruction of superior mesenteric artery
• infarction & gangrene
• bilious emesis (bile vomiting)

Question 31

reversed rotation of the gut results in?

Answer 31

clockwise rotation:

• duodenum anterior to SMA
• transverse colon posterior to SMA

Question 32

what is subhepatic cecum and appendix?

Answer 32

cecum adheres to liver upon its return to the abdomen; small liver; appendix higher than normal

Question 33

a mobile cecum can cause?

Answer 33

• right inguinal hernia
• abnormal location of appendix
• volvulus

Question 34

atresia or stenosis of intestine occurs from?

Answer 34

abnormal recanalization of intestine during development

Question 35

inflammation of an ileal diverticulum mimics the symptoms of?

Answer 35

appendicitis

Question 36

an ileal diverticulum is a remnant of?

Answer 36

proximal omphaloenteric duct (has pancreatic and gastric tissues)

Question 37

congenital megacolon (Hirschsprung’s disease) causes?

Answer 37

• absence of ANS ganglion in myenteric plexus distal to megacolon
• prevents movement of stool
• mostly in rectum and sigmoid colon

Question 38

what causes Hirschsprung’s disease?

Answer 38

failure of neural crest cells to migrate into wall of colon

Question 39

what is an imperforate anus?

Answer 39

• blind end of anal canal
• an ectopic anus
• anoperineal fistula (vagina or urethra)

Question 40

what is the most common type of anorectal birth defect?

Answer 40

blind end of rectum (anorectal agenesis) with or without fistula to vagina, bladder, or urethra

Question 41

what causes anorectal agenesis?

Answer 41

incomplete separation of cloaca from UG sinus by urorectal septum