Nursing Entrance Exam

same. The receptors provide information from sensations of these mechanoreceptors, or hair cells. The inner ear boasts a complex structure; the arrangement of accessory structures enables hair cells to respond to various stimuli, thus providing input for both senses.

Anatomy of the Ear The ear is divided into three anatomical regions: the external ear, the middle ear, and the inner ear. The External Ear The external ear includes the fleshy and cartilaginous auricle, or pinna, which surrounds the external acoustic meatus, or ear canal. The purpose of the auricle is to protect the opening of the canal and to provide directional sensitivity. The external acoustic meatus is a channel that ends at the tympanic membrane, also referred to as the tympanum or eardrum. The tympanic membrane is a thin, semitransparent sheet that separates the middle ear from the external ear. Ceruminous glands – integumentary glands along the external acoustic meatus – secrete a waxy material that helps deny access to foreign objects or small insects, as do many small, outwardly projecting hairs. The slightlywaxy secretion of the ceruminous glands (cerumen) also slows microorganism growth in the external acoustic meatus, and it helps to reduce the chances of infection. The Middle Ear The middle ear, or tympanic cavity, is an air-filled chamber separated from the external acoustic meatus by the tympanic membrane. The middle ear communicates with the

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