Bronchial pouch derivatives

1st pouch       middle ear cavity

                       eustachian tube

                        mastoid air cells

2nd pouch      epithelial lining of the palatine tonsil

3rd pouch  --  dorsal wings--   INFERIOR parathyroids

3rd pouch -- ventral wings --- thymus

 

4th pouch -- dorsal wings --- SUPERIOR parathyroid

Abnormal development of 3rd & 4th pouches:  DiGeorge syndrome

MEN 2A:

1) pheochromocytoma (adrenal medulla)

2) parathyroid tumor (3rd & 4th pharyngeal arches) 

3) parafollicular cells (medullary thyroid cancer);