Youtor
Anatomy of the Ear
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The ear is the organ of hearing and, in mammals, balance. In mammals, the ear is usually described as having three parts—the outer ear, the middle ear and the inner ear. The outer ear consists of the pinna and the ear canal. Since the outer ear is the only visible portion of the ear in most animals, the word ear often refers to the external part alone.The middle ear includes the tympanic cavity and the three ossicles. The inner ear sits in the bony labyrinth, and contains structures which are key to several senses: the semicircular canals, which enable balance and eye tracking when moving; the utricle and saccule, which enable balance when stationary; and the cochlea, which enables hearing. The ears of vertebrates are placed somewhat symmetrically on either side of the head, an arrangement that aids sound localisation. • The ear develops from the first pharyngeal pouch and six small swellings that develop in the early embryo called otic placodes, which are derived from ectoderm. • uring approximately the 6th and 8th months the auricles forms from 6 Mesenchymal condensations in the 1st and 2nd Pharyngeal Arches , these are known as the auricular hillocks. Around the external acoustic meatus, three of each of these auricular hillocks can be found on each side. With Further Development they form the definitive auricle. • #pgnotes #medicos #ENT
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