Hirschsprung disease (congenital aganglionosis of the distal colon) results from failure of which cell population to colonise the developing hindgut?

• A Vagal neural crest cells ✓
• B Lateral plate mesoderm progenitors
• C Sacral neural crest cells exclusively
• D Splanchnic mesoderm cells

Explanation

Enteric neurons of the gastrointestinal tract are colonized predominantly by vagal neural crest cells (arising from the post-otic hindbrain, somites 1-7) that migrate rostrocaudally along the gut. Mutations in RET (receptor tyrosine kinase), GDNF, or EDNRB/EDN3 impair this migration, leaving the distal colon aganglionic. Sacral neural crest cells contribute a small caudal plexus but cannot compensate for absent vagal contribution to the entire aganglionic segment. Lateral plate mesoderm gives rise to the smooth muscle and connective tissue of the gut wall, not the enteric neurons.

Reference: BD Chaurasia's Human Anatomy, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.