The ears are composed of the external ear, the middle ear, and the inner ear. The external and middle ear collect and convey sound to the inner ear where sensory receptors for the auditory system reside. Sensory receptors for the vestibular system are also in the inner ear and function independently of the external and middle ear. The auricle consists of a single irregular plate of elastic cartilage. It is covered by a thin layer of keratinized stratified squamous epithelium containing hairs and sebaceous glands.
Sweat glands are present in the skin covering the posterior aspect of the auricle.
The outer one-third is composed of elastic cartilage that is continuous with the auricle. The inner two-thirds is formed by temporal bone. Epithelium changes from keratinized to non- keratinized near the tympanic membrane. Secretions of sebaceous and ceruminous glands combine to form cerumen which protects the skin from desiccation and helps to keep foreign bodies out of the ear. It converts sound waves from the external ear into mechanical vibrations that are conveyed to the inner ear.