Hirschsprung disease: Hirschsprung disease is a disease of the enteric nervous system where there is a lack of or absence of ganglion cell in the myenteric and meissner's  plexus of the intestine. 

It's a congenital disease.

Fate of Primitive heart tube:

 

      Parts and their Adult structures are given below:

•   Trancus Arteriosus
• Aorta
• Pulmonary trunk 
•  Bulbus cordis    
• smooth part of right ventricle (conus arteriousus)
• smooth part of left ventricle (aortic vestibule)
•  Primitive  ventricle:
• trabeculated  part of right ventricle
• trabeculated part of left ventricle
•  Primitive atrium:
• trabeculated  part of right atrium
• trabeculated part of left atrium
•  Sinus venosus (  right horn & left horn )
• smooth part of right atrium ( sinus venarum )
• coronary sinus
• oblique vein of left atrium

Brilliantly transilluninable swellings

1. Cystic hygroma
2. Congenital hydrocele
3. Meningocele with thin skin cover
4. Ranula
5. Epididymal cyst