Planet Earth and Its Environment A 5000-million year Journey

Biology in Focus, HSC CourseGlenda Childrawi, Margaret Robson and Stephanie Hollis

CommunicationTopic 11: The Human Ear1DOT Point(s) describe the anatomy and function of the human ear, including:pinnatympanic membraneear ossiclesoval windowround window cochleaorgan of Cortiauditory nerveOutline the role of the Eustachian tubeThe External EarThe external ear is also referred to as the outer ear. It is comprised of the:Pinna (pinnae is plural): the floppy bitMeatus: the auditory canalTympanic Membrane: the outer layer of the eardrum

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The Middle EarThe middle ear is an air-filled cavity. It is separated from the external ear by the tympanic membrane and connected to the throat by the Eustachian tube.

The Middle EarThe middle ear opens into the inner ear through the oval window. Inside the cavity are three small bones, which could fit into a 5 cent coin. These bones are connected by true joints and form a system of levers. These bones are easily damaged by noises.www.smh.com.au

The Inner EarThe inner ear is formed by a series of bony canals. It can be divided into three parts:Vestibule (entrance)Semicircular canalsThe cochleawww.kids-ent.comThe Inner EarThe vestibule and the semi-circular canals play no part in hearing but are three dimensional sensors for balance. The cochlea is a spiral bony canal, which houses the organ of Corti. encyclopedia.lubopitko-bg.com

The Inner EarEach hair cell of the organ of Corti has a nerve fibre attached. These lead to the auditory nerve, which carries impulses to the hearing centres in the cortex of the brain.cnx.org

The Eustachian TubeThe Eustachian tube helps to equalise air pressure on either side of the tympanic membrane by bringing in air from the mouth.thestudiofiles.comActivity-Handout Human Ear Diagram-Handout Table 6.1 The Human Ear-Watch How the Ear Works VideoActivity-Students to Complete DOT Point 6.3 The Mammalian Ear