Biology in Focus, HSC Course Glenda Childrawi, Margaret Robson and Stephanie Hollis Communication Topic 11: The Human Ear

DOT Point(s) describe the anatomy and function of the human ear, including: pinna tympanic membrane ear ossicles oval window round window cochlea organ of Corti auditory nerve Outline the role of the Eustachian tube

The External Ear The external ear is also referred to as the outer ear. It is comprised of the: Pinna (pinnae is plural): the floppy bit Meatus: the auditory canal Tympanic Membrane: the outer layer of the eardrum best-diving.org

The Middle Ear The 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 Ear The 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.

The Inner Ear The inner ear is formed by a series of bony canals. It can be divided into three parts: 1. Vestibule (entrance) 2. Semicircular canals 3. The cochlea

The Inner Ear The 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 Ear Each 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 Tube The Eustachian tube helps to equalise air pressure on either side of the tympanic membrane by bringing in air from the mouth. thestudiofiles.com

Activity -Handout Human Ear Diagram -Handout Table 6.1 The Human Ear -Watch How the Ear Works Video

Activity -Students to Complete DOT Point 6.3 The Mammalian Ear