Ear Physiology Flashcards
What is the bony labyrinth?
A system of torturous channels worming though the bone
What fluids are filled in the labyrinth?
Perilymph and endolymph
What is endolymph fluid?
Potassium rich intracellular fluid
What is perilymph fluid?
Similar to CSF and continuous with it
What does the saccule and utricle vestibules do?
House equilibrium receptor regions (maculae)
What are the 3 semicircular canals?
Anterior, posterior and lateral
What does maculae do?
Responds to the pull of gravity and report on changes of head position
What do the semicircular canals do?
Holds the semicircular ducts
Help you keep your balance
The semicircular canals have….
ampulla
What does the ampulla do?
Houses an equilibrium: rotational movements of the head
What are 4 layers part of the cochlea?
Scala vestibuli, scala media, scali tympani and basilar membrane
The scala vestilbuli is part of what and contains what?
Part of the bony labyrinth, contains perilymph
The scala media is part of what and contains what?
Part of the membranous labyrinth and contains endolymph
The scala tympani is part of what and contains what?
Part of the bony labyrinth and contains perilymph
What does the basilar membrane do?
Sound reception, near the oval window, gradually widens and thins as it approaches the cochlear apex
What is frequency?
It is perceived as pitch (peak to peak graph)
What is pitch?
Hertz (different sound frequencies)
How many Hz can we hear?
20 to 20,000
What Hz do we hear best?
1,500 to 4,000
What is amplitute?
The height of the wave of the wavelength graph (its intensity)
10 dB (decibels) has ___ more times energy then ___ dB
10, 0
20 dB is _____ as loud as ____
twice, zero
20 dB has ___ times more energy than 0 dB (10 x10)
100
What is the 1st place people can hear?
0 dB
How many dB: Quiet library/soft whisper
30 dB
How many dB: Busy traffic, noisy restaurant
70 dB
How many dB: Gunshot, jet plane
140 dB
What is the auditory pathway?
- Afferent cochlear nerve
- Spiral ganglion
- Medulla (potential of crossing over)
- Midbrain (thalamus - startle reflex) and inferior colliculi (head turn when hearing a noise)
- Auditory cortex
What is a maculae?
Sensory receptor organs that monitor the position of the head in space (has the little cilia hairs)
What is the kinocilium?
The tallest cilia of the maculae
Tilting the head forward, hairs bend ________ kinocilium
toward
Tilting the head forward, nerve fibers are excited or inhibited?
Excited
Tilting the head forward, the hair cells depolarize or hyperpolarize?
Depolarize
Tilting the head backwards, hairs bend ________ kinocilium
away
What are the 2 different types of equilibrium?
Maculae and ampulla (static and dynamic)
Maculae (static) is:
Non-rotational
Ampulla (dynamic) is:
Rotational
What are examples of non-rotational?
Horizontal and vertical
The posterior semicircular canal tilts the head:
Left and right
The superior semicircular canal tilts the head:
Nodding
The horizontal semicircular canal tilts the head:
Shakes head no
The vestibule is on the opposite side of the _____ __________
oval window
What are the 2 types of macula?
Utricle and Saccule
The saccule picks up on _______ movement
vertical
The utricle picks up on ________ movement
horizontal (acceleration and deceleration)
