Embryology of the Abdomen Flashcards
the splanchnic mesoderm forms _
mesentery, muscle, connective tissue, and blood vessels of digestive tube
What does the endoderm form in the digestive tract?
epithelial linings, bile ducts and gallbladder, parenchyma of liver (hepatocytes), and parenchyma of pancreas (enzymes and endocrine cells)
foregut organs
esophagus, stomach, liver, gallbladder, pancreas, upper duodenum
foregut arterial supply
celiac trunk
foregut nerve supply
vagus (parasympathetic) and thoracic splanchnics (sympathetic)
midgut organs
lower duodenum, jejunum, ileum, cecum, appendix, ascending colon, proximal 2/3 of transverse colon
midgut arterial supply
superior mesenteric arteries
midgut nerve supply
vagus (parasympathetic) and thoracic splanchnics
hindgut organs
distal 1/3 of transverse colon, descending colon, sigmoid colon, rectum, upper anal canal
hindgut arterial supply
inferior mesenteric arteries
hindgut nerve supply
pelvic splanchnics (parasympathetic) and lumbar/sacral splanchnics (sympathetic)
pyloric sphincter allows _
movement from stomach to duodenum
pyloric stenosis
hypertrophy of pyloric sphincter (always contracted) so shuts off flow from stomach to duodenum
pyloric stenosis symptoms
olive-shaped mass, visible peristalsis, and nonbilious projectile vomiting
pyloric stenosis is associated with _
exposure to antibiotics during pregnancy
bile duct atresion
leads to lack of bile entering the duodenum and dilation of gallbladder and ducts above blockage; bowl movements are clay colored
ventral pancreatic bud develops as an extension of _
common bile duct
dorsal pancreatic duct forms as an extension of _
stomach
annular pancreas
migration of ventral pancreatic duct is disrupted causing a ring of tissue around the duodenum that blocks movement of digestive products
subhepatic appendix
appendix ends up underneath the liver because ascending colon does not migrate left
umbilical herniation
abdominal cavity is too small for organs at first but as it expands the guts will go back in
omphalocoele
guts did not go back in and are covered with amnion/peritoneum
gastroschisis
guts did not go back in but are exposed (no amnion covering)
vitelline fistula
vitelline ducts fail to close causing meconium discharge from umbillicus
meckel diverticulum
partial closure of vitelline duct but remaining attachment to ileum; can have gastric or pancreatic tissue secreting HCl so will have ulcerations
intussuception
one segment of intestine is inside of another causing obstruction
volvulus
abnormal twisting of GI tract
duodenal atresia
failure to recanalize; associated with Down Sydndrome
jejunal and ileal atresia
often a result of volvulus; leads to necrosis of fetal intestine
urorectal septum
if it does not form it can result in urorectal fistula, rectovaginal fistula, or rectoperineal fistula; all result in anal agenesis
congenital megacolon (Hirschsprung)
neural crest cells fail to migrate into a portion of hindgut resulting in distended colon
