The Special Senses Lesson 2: The Senses of Hearing, Taste, Smell and Touch

Lesson Objectives Upon completion of this lesson, students should be able to … Describe the anatomy of the ear and briefly explain the function of each structure.

Lesson Objectives Describe the anatomy of the nose and explain how the sense of smell occurs. Identify the anatomical structures that make up the special senses. Discuss the sense of taste, and briefly explain the function of taste buds.

Anatomy of the Ear 4

Three Main Divisions of the Ear External ear Middle ear Inner ear 5

Label ear

Structure and Function of the External Ear Pinna, or auricle: Funnels sound waves Auditory canal, or auditory meatus: S-shaped, secretes cerumen

Structure and Function of the External Ear Tympanic membrane, or eardrum: Separates the external ear from the middle ear

Take a closer look: Otoscope

Structure and Function of the Middle Ear Contains : malleus (hammer), incus (anvil), stapes (stirrup) Function Transmits sound vibrations Equalizes air pressure Protects from damaging noise

Structure and Function of the Inner Ear Bony labyrinth : Cochlea, vestibule, and three semicircular canals Cilia=Tiny hair cells

Structure and Function of the Inner Ear Eustachian tube extends from the middle ear to the nasopharynx

Hearing test http://www.freehearingtest.com/test.shtml Or use audiometer

Path of Sound Vibrations 14

Two Most Common Types of Hearing Disorders Conductive: Hearing loss can be corrected Sensorineural: Hearing loss cannot be corrected

Four Types of Taste Cells Sweet Sour Salty Bitter

The Sense of Touch Oldest, most primitive sense More nerve endings equals more sensitivity

Medical Specialists Ears, nose and throat specialist