Early Embryonic Development › Drawing Highlights

Endoderm Derivatives

Notes

Endoderm Derivatives

Endoderm

The foregut

Derives the linings of many important gastrointestinal and respiratory structures:

  • The pharyngeal region
  • Divides distally into the esophagus and trachea and includes 4 key pharyngeal pouches of the head and neck.
  • Stomach
  • Proximal duodenum,
  • Liver buds, which ultimately form the liver,
  • The gallbladder,
  • The pancreas, which forms from the ventral and dorsal pancreatic buds (aka, diverticula).
  • The linings of the respiratory system (with a drawing of the trachea and lungs).

The midgut

  • Distal duodenum,
  • Jejunum,
  • Ileum,
  • Ascending colon,
  • Proximal 2/3 of the transverse colon.

The hindgut

Gives rise to the allantois before ending blindly at the cloaca.

  • Distal 1/3 of the transverse colon,
  • Descending and sigmoid colons, and,
  • The proximal 2/3 of the anorectal canal. The ectoderm gives rise to the distal 1/3 of the anorectal canal is derived from ectoderm; it invaginates the area around the proctodeum (aka, anal pit).