GI development S2M2

  1. The mouth is formed by the opening of the buccopharyngeal membrane when
    4th week
  2. Stomodeum
    Mouth opening
  3. The opening of the anus and urethra happens when
    7th week when the cloacal membrane ruptures
  4. What is the blood supply to the Foregut
    Celiac artery
  5. What is the blood supply to the midgut
    Superior mesentaric artery (SMA)
  6. What is the blood supply to the hindgut
    Inferior mesenteric artery (IMA)
  7. What structures are in the foregut
    • Pancreas
    • Liver
    • Top of duodenum
    • Stomach
    • Esophagus
  8. What areas are part of the Pharyngeal gut
    • Oral cavity
    • Pharynx
  9. What structures are part of the midgut
    • Duodenum (distal portion)
    • Jejunum
    • Ileum
    • Colon (up to midpoint in transverse)
  10. What structures are part of the Hindgut
    • Colon (half of transverse down)
    • Rectum
    • Anal canal
    • Sigmoid colon
  11. How is the intraembryonic cavity formed
    An arm from each side of the embryonic cavity located dorsal to the neural tube, wraps around the gut tube leaving the intraembryonic cavity separating the gut tub from the amnionic cavity
  12. Where is the dorsal mesentary located before the stomach rotation
    On the dorsal side of the gut tube connecting it to dorsal body wall
  13. What is the definition of mesentery
    Double layers of peritoneum that enclose an organ and connect it to the body wall
  14. What organs are located in the dorsal mesentery before stomach rotation
    • Tail of pancreas
    • Spleen
    • Stomach
  15. What organ is located in the ventral mesentery before the rotation of the stomach
  16. Dorsal mesentery is found attached where from superior to inferior
    Lower end of the esophagus to cloacal region of the hindgut
  17. What mesentery forms the falciform ligament and lesser omentum
  18. What artery is found in the mesentery proper
    Superior mesenteric artery (SMA)
  19. What artery is found in the dorsal mesocolon
    Inferior mesenteric artery (IMA)
  20. What mesentery eventually forms the greater omentum
    Dorsal mesogastrium
  21. In what regions is the ventral mesentery found from superior to inferior
    Terminal esophagus, stomach (lesser curvature), to the upper part of the duodenum
  22. What layers of the esophagus are derived from visceral mesoderm
    • Lamina propria
    • Muscularis mucosae
    • Submucosa
    • Muscularis externa
    • Adventitia/serosa
  23. What is the only portion of the esophagus derived from endoderm
    Epithelial lining and glands
  24. When does the respiratory diverticulum begin to develop
    Week 4
  25. Esophageal atresia is almost always associated with
  26. What are the histological changes that the esophageal epithelium undergoes during development
    • Stratified columnar
    • Occlusion of lumen
    • Reopen with simple columnar epithelium (Barretts)
    • Multilayered ciliated columnar
    • Sratified squamous
  27. What is the condition called when the epithelium in the esophagus is simple columnar instead of Non-karetenized stratified squamous
    Barretts esophagus
  28. When does the stomach first appear and what does it look like
    4th week, dilation of the foregut
  29. How does the stomach position change during development
    It rotates 90º clockwise
  30. Where are the vagus nerves and ventral/dorsal mesentery before and after stomach rotation
    Vagus nerves are on the lateral sides and the mesentery are ventral and dorsal before rotation

    • The vagus nerves end up having the left vagus on the anterior wall and right vagus posterior wall of stomach
    • Dorsal mesentery ends up of the left side of the stomach and ventral on the right
  31. The greater omentum is formed by the
    Continual growth of the dorsal mesentary
  32. The gastric epithelium develops how
    Rugae appear first, then the gastric pits
  33. When does HCl production begin
    Shortly before birth
  34. When a baby has projectile vomiting habitually following feeding what would you be suspicious of
    Congenital pyloric stenosis
  35. The spleen is dervied from
    Mesoderm (sandwiched between dorsal mesentery)
  36. Define intraperitoneal
    Organs that are enclosed by a double layer of peritoneum that connects it to the body wall
  37. Define retroperitoneal
    Organs that lie against the posterior body wall and are covered by a single layer of peritoneum on their anterior surface (non-mobile)
  38. How does the function of the spleen change in development
    Initially it functions as a hematopoietic organ and from the 4th month on it begins transformation into a lymphatic structure
  39. When the spleen eventually becomes a lymphatic structure at month four, what cells arrive first
    T precursor cells and then B cells
  40. How do the pancreas and duodenum end up becoming retroperitoneal
    They are pressed against the dorsal body wall and fuse with the peritoneum
  41. What happens to the duodenum during the 2nd month of development
    There is epithelial proliferation, obliteration of the lumen, followed by recanalization (cavity formation)
  42. When does the liver begin to bud from the gut tube
    4th week of development
  43. What is in the ventral mesogastrium
    Falciform ligament and lesser omentum together
  44. The septum transversum during early development is located
    Between the developing heart and liver
  45. Septum transversum becomes
    Central tendon of the diaphragm and ventral mesentery
  46. The Septum transversum appears when, and is derived from
    • Appears on day 22
    • Splanchnic mesoderm
  47. Where on the liver is there no peritoneum
    Where it is in contact with the diaphragm
  48. What is the space called behind the lesser omentum and stomach
    Epiploic foramen of Winslow
  49. How do the functions of the liver change during development
    • Hematopoiesis - 5-6th weeks
    • Bile production - 12th week
  50. Meconium
    First bowel movement
  51. The epithelial lining of the bile ducts and mucosal glands of the gallbladder are derived from
    Endodermal derivatives
  52. The lamina propria, muscularis externa, and adventitia of gallbladder are derived from
    Mesodermal derivatives
  53. Both the endocrine and exocrine portions of the pancreas are derived from
  54. Glucogon and Insulin are first detected in the fetal plasma when
    • Glucogon - 15th week
    • Insulin - 5th month
  55. Why in pregnancy of a diabetic is the baby larger
    Glucose crosses the placenta and stimulates fetal islets accelerating their development and insulin secretion thus causing the storage of fats
  56. The ascending and descending colon are what type of peritoneum
  57. Omphalocele
    Failure of return of the intestinal loop into the body cavity after physiological herniation (intestines are outside the body wall)
  58. Gastrochisis
    Herniation of abdominal contents through a defect in the abdominal wall directly into the amniotic cavity (not covered by amnion or peritoneum)
  59. The anus and urinary tract develop from
    The cloaca subdividing into the anorectal canal and urogenital sinus divided by the urorectal septum
  60. Blood supply to the anal canal is
    • Cranial portion - Superior rectal artery (IMA)
    • Caudal portion - Inferior rectal artery (branch of internal pudendal)
  61. Imperforate anus
    No anal opening
  62. Rectoanal atresia and fistula
    Ectopic positioning of the anus, opening into the urethra
  63. Differentiation of the primitive gut tube into different organs depend on
    Interaction between mesoderm HOX genes and Endoderm Sonic Hedge Hog (SHH) genes
  64. What is the role of HOX genes in gut development
    They dictate the type of structure that will form when induced by Sonic Hedge Hog (SHH)
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GI development S2M2