Middle and internal ear

Middle ear

The 1st pharyngeal pouch gives rise to the tubotympanic recess, which develops further to form the cavity of the middle ear. The 1st pharyngeal cleft gives rise to the external acoustic meatus, which is lined with ectoderm. Three mesenchymal condensations develop into auditory ossicles in the area between the otic vesicle, the external acoustic meatus and the tubotympanic recess. The malleus and the incus originate mainly from the cartilage of the first pharyngeal arch, while the stapes is derived mainly from the cartilage of the second pharyngeal arch.