Class Notes (835,494)
Canada (509,211)
ANAT 101 (98)
Lecture

Lecture #18 - The Ear.doc

9 Pages
111 Views
Unlock Document

Department
Anatomy and Cell Biology
Course
ANAT 101
Professor
Richard Oko
Semester
Winter

Description
Lecture #18 - The Ear and the Auditory and Vestibular Systems Regions of the Ear external/outer ear -> collects + directs sound waves middle ear -> amplifies sound waves internal/inner ear -> contains sensory organs for hearing and balance EXTERNAL EAR • directs waves towards tympanic membrane • lateral 1/3 of canal = cartilage • medial 2/3 = temporal bone THE MIDDLE EAR • air-filled bony compartment with several key features -3 bones (ossicles): vibrate to amplify sound waves -malleus, incus, stapes -2 muscles: control excessive vibration of ossicles -tensor tympani and stapedius -Eustachian tube: connects ear to nasopharynx -equalizes air pressure -drains mucus build up Otitis Media (middle ear infection) -earache, fever, hearing loss -caused by fluid buildup in tube -occurs more in children -have a shorter, more horizontal tube -can cause perforation of tympanic membrane THE INTERNAL EAR • 3 sensory organs -hearing -> cochlea Lecture #18 - The Ear and the Auditory and Vestibular Systems -balance/equilibrium -> semicircular canals, vestibule -openings (windows) to middle ear -> oval window, round window Cochlea -auditory system (hearing) -spiral shaped structure containing Organ of Corti (transduces sound waves into electrical impulses for brain) Vestibule -vestibular system (balance) - static equilibrium -located between cochlea and semicircular canals -made up of utricle and saccule -> detect gravity and linear acceleration Semicircular canals -vestibular system (balance) - dynamic equilibrium -3 canals (anterior, posterior, lateral) that detect complex rotational motion -bony labyrinth contains perilymph surrounding membranous labyrinth -membranous labyrinth contains endolymph filling the sensory structures AUDITORY SYSTEM and Cochlea • movement of stapes spread fluid waves through compartments of cochlea (from oval window to round window) 2 compartments (separated by cochlear duct) • 1) scala vestibuli 2) scala tympani Lecture #18 - The Ear and the Auditory and Vestibular Systems Organ of Corti (aka spiral organ in cochlear duct) -where sound transduction takes place through hair cells The Hair Cell • sensory receptor that transduces mechanical and electrochemical energy • stereocilia: fingerlike projections on apical surface of cell • activation of cell occurs mechanically by bending of stereocilia • activated hair cell releases NT, stimulates sensory neuron to brain Lecture #18 - The Ear and the Auditory and Vestibular
More Less

Related notes for ANAT 101

Log In


OR

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit