Question

which embryonic structure gives rise to the thymus gland?

a.

Third pharyngeal cleft

b.

Second pharyngeal arch

c.

Third pharyngeal arch

d.

Fourth pharyngeal pouch

e.

Third pharyngeal pouch​

Answer 1

Answer:

the hyoid bone is derived from neural crest associated with pharyngeal arches II and III. the laryngeal cartilages are derived from neural crest associated with pharyngeal arches IV and VI.

Answer 2

Answer:

According to the classical view, the thymus derives from the endoderm of the 3rd pharyngeal pouch on both sides. The 3rd pharyngeal pouch gives origin ventrally to the thymus and dorsally to the 3rd parathyroid gland, whereas the 4th pharyngeal pouch gives origin to the 4th parathyroid and the ultimo- branchial body.