First pharyngeal pouch- form tubotympanic recess
1. Proximal part of tubotympanic recess: Auditory / Eustachian tube
2. Distal part of tubotympanic recess: Tympanic / Middle ear cavity
3. Inner layer (Endoderm) of tympanic membrane
Secound pharyngeal pouch-
1. Palatine tonsil
2. Tonsilar fossa
Third pharyngeal pouch-
1. Ventral region: Thymus
2. Dorsal region: Inferior parathyroid gland
Fourt pharyngeal pouch-
1. Ventral region: Ultimobranchial body
2 Dorsal region: Superior parathyroid gland
NOTE: The parathyroid glands (superior and inferior) are located on the posterior/dorsal side of the thyroid, so the parathyroid glands (superior and inferior) are derived from the dorsal region of the 4th and 3rd pharyngeal pouches.
Reference:
1. Langman's medical embryology, 13th edition, P. No. 284-86