Class Notes (839,150)
Canada (511,218)
55-101 (38)
Habetler (38)

Hair Cells

1 Page

Biological Sciences
Course Code

This preview shows half of the first page. Sign up to view the full page of the document.
Outline of Lecture 56 (03-24 A; Fuchs) Hair Cells I. Introduction to hearing - Sound is a pressure wave, and pure tones can be characterized by amplitude (measured indirectly as dB) and frequency - Dynamic range of hearing in humans is about 0-100 dB (whisper to pain) and 20-20,000 Hz - Types of damage to ear - Chronic severely loud sound exposure kills hair cells - Ototoxic antibiotics, e.g. streptomycin or gentamicin, kills hair cells - Hearing loss of high frequencies with age, aka presbycusis I. Anatomy of the ear A) Outer ear - Pinna: funnels and amplifies sound, sound shadows provide resolution of sound origin - External auditory canal: acts as resonant tube for 4 kHz tones B) Middle ear - Impedance matching of air to water sound transmission by two mechanisms (1) Lever advantage of ossicles (malleus, incus, stapes) (2) Oval window of stapes is smaller than eardrum - Middle ear muscles (tensor tympani, stapedius): restrict ossicle movement in response to loud sound to prevent damage - Damage in the middle ear is called “conductive” C) Inner ear (more on cochlea below) - Damage in the inner ear is called “sensorineural” III. The Cochlea - Memorize cochlear structure (e.g. figure on p. 5) - Stereocilia of hair cells are arranged in rows of increasing height and are embedded in the tectorial membrane; shear of basilar membrane WRT tectorial membrane causes displacement of hair bun
More Less
Unlock Document

Only half of the first page are available for preview. Some parts have been intentionally blurred.

Unlock Document
You're Reading a Preview

Unlock to view full version

Unlock Document

Log In


Join OneClass

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

Sign up

Join to view


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.