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Flashcards in Refraction Deck (43)
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0
Q

how much is a 10 fold increase in sound energy?

A

1 bel

1
Q

What is the measurement of a decibel_

A

1/10 log (I* measure sound / I * standard sound)

2
Q

What is energy proportional to?

A

energy is proportional to the square of pressure

3
Q

what is the decibel of a whisper?\

A

20 dB

4
Q

What is the decibel of normal conversation?

A

60dB

5
Q

What is the decibel of a symphony?

A

100dB

6
Q

what is the decibel of threshold of discomfort?

A

130dB

7
Q

What is the decibel for threshold of pain

A

160dB

8
Q

In a young adult what are the frequencies of audible sound?

A

20-20k Hz (decreases with age)

9
Q

IN what frequency is the greatest acuity for audible sound?

A

1000-4000 Hz

10
Q

In what range does impedance matching work?

A

300-3000 HZ perfect for sound (50-75%)

11
Q

How much smaller is the oval window compared to the Tympnic membrance?

A

17 times

12
Q

What does the ossicular system do?

A

reduces amplitude by 1/4

increases pressure against oval window by 22 times (gives increased force of 1.3 times)

13
Q

By how many decibels can the ossicular system reduce loudness if not working?

A

15-20 dB

14
Q

When the stepedius muscles pulls the stapes outward it does what to sound?

A

decreases sound

15
Q

When the Tensor Tympani pulls the malleous inward what does it do to sound?

A

increases loudness

16
Q

When a CNS reflex causes the contraction of sapedius and tensor tympani muscles, it is called?

A

creation of rigid ossicular sytem

17
Q

what does a rigid ossicular sytem do?

A

reduces ossicular conductions

18
Q

What are the chambers of the cochlea?

A

Scali vestibuli, Scali media, Scali tympni

19
Q

What seperates the Scali Vestibuli and Scali media?

A

Reissner’s membrane

20
Q

What seperates the Scali media from the Scali tympani?

A

basilar membrane

21
Q

what two chambers of cochlea are filled with perilymph?

A

Scali vestibuli and Scali Tympani

22
Q

What are the top of hair cells bathed by in the Scali media?

A

endolymph

23
Q

What cation is the Scali media enriched with?

A

Enriched with K+ that is secreted by stria vacularis

24
Q

What secretes the K+ that enriches the Scali media?

A

stria vacularis

25
Q

what chamber is associated with the round window?

A

Scali tympani

26
Q

What chamber is associated with the oval window?

A

Scali vestibuli

27
Q

What is the scala media filled with?

A

endolymph (K+)

28
Q

What is the cala tympani filled with?

A

perilymph (CSF)

29
Q

what baths the bottoms of hair cells?

A

perilymph

30
Q

what frequencies do the hair cells near the oval window respond to?

A

> 4500Hz

31
Q

what are the characteristics of hair cells near oval window (base)?

A

short and thick

32
Q

What are the characteristics of the hair cells near helicotrema?

A

long and slender.

33
Q

to what frequencies do the hair cells near helicotrema respond to best?

A

best to lower frequencies (<200Hz)

34
Q

What does the cochlea behave like?

A

Fourier analyser (kind of auditory prism)

35
Q

What is Fourier analysis?

A

any complex wave ca be broken down into its component sine waves with differing phases frequencies, and amplitudes

36
Q

What is the organ of corti?

A

cochlea

37
Q

where is the primary auditory cortex located?

A

superior gyrus of temporal lobe

38
Q

where are high frequency sounds located in the cortex?

A

posterior

39
Q

where are low frequency sounds located in the cortex?

A

anterior

40
Q

what pathway involves direct stimulation of cochlea through the vibration of the skull as the cochlea is imbedded in the petrous portion of the temporal bone?

A

bone conduction pathway

41
Q

what pathway involves the external ear canal, middle ear, and inner ear?

A

air conduction pathway

42
Q

IF a weber test sounds louder in bad ear, what is suspected?

A

air conduction loss in bad ear (external canal or ossicles involved)