A. Brachial cyst.
B. Brachial cleft.
C. Brachial pouch.
D. Brachial arch.
Anc;C. Brachial pouch
The gland marked as “A” in the picture above represents the Parathyroid gland.
- The parathyroid glands develop from the endoderm of the third and fourth pharyngeal pouches (Brachial Pouch). The thymus is also derived from the third pharyngeal pouch.
- The endodermally lined pharyngeal pouches, transient in nature, give rise to important structures. The derivatives of the pharyngeal pouches has a dorsal and a ventral part.
|Pouch 1||ventral||Obliterated: no derivative|
|dorsal||pharyngotympanic tube and middle ear cavity|
|Pouch 2||Ventral||palatine tonsil,partially obliterated by endoderm|
|dorsal||contributes to pharyngotympanic tube|
|dorsal||inferior parathyroid gland|
|Pouch 4||ventral||ultimobranchialbodies (C-cells of thyroid gland)|
|dorsal||superior parathyroid gland|