EMBRYOLOGY OF DIGESTIVE SYSTEM - 2
Dr. ANAND SRINIVASAN
5 Dec 2011
OBJECTIVES
Students at the end of the class should be able to :
Understand and explain the rotation of midgut and its clinical correlates
Formation, derivatives of hindgut and its clinical correlates
MIDGUT
Communicates with yolk sac – Vitelline duct
Supplied by – Superior mesesteric A.
Formation of ‘primary intestinal loop’
Physiological umbilical herniation
Rotation of Midgut
Counterclockwise rotation – 90° + 180 °
Retraction of herniated loops
Cecal bud – last to enter abdominal cavity
Distal end of cecal bud – Appendix
Omphalocele
Gastrochisis
SURVIVAL RATES
Meckel’s diverticulumm
Abnormal rotation of gut
Reversed Rotation
Volvulus
Gut atresia and stenosis
HINDGUT
Distal 1/3 of transverse colon – upper part of anal canal
Hind gut – Cloacal membrane
Allantois – Primitive urogenital sinus
Formation of ‘Urorectal septum’
Ectoderm part – proctodeum
Cloacal membrane (Anal membrane)
Pectinate line
Hindgut abnormalities
Congenital megacolon
RECOMMENDED READING
LANGMAN’S MEDICAL EMBRYOLOGY – 11th edition
CHAPTER 14 – Digestive system Pgs. 223 – 233