Neuro700 - Hearing & visual Pathway (Quiz 5)

What is the function of external ear?

collect soundwaves

What is filled within the cavity in the middle ear?

Air

What are the structures of external ear

• Auricle / Pinna ( Helix, Lobule)

• External auditory canal

• Targus

• Tympanic membrane / eardrum

• Ceruminous gland

What is Tympanic membrane made of? color?

Epidermis

collagen

elastic fibers

color: Semitransparent

What is the treatment for perforated eardrun?

No Treatment, heals within a month

What produces earwax?

Ceruminous gland

Why we shouldn’t use cotton swab to clean earwax?

• will cause perforated eardrum

• earwax dries up and falls out of ear canal

What is the function of cerumen?

• prevent dust and foreign object from entering the ear canal

• prevent damage from water or insects

What separates the middle ear from external ear and inner ear?

External ear: eardrum ( tympanic membrane_

Inner ear: Oval window and round window

How are the auditory ossicles connected?

Synovial joints

What are the 3 auditory ossicle in middle ear?

• Malleus

• Incus

• Stapes

What are the muscle in the middle ear

• Tensor Tympani

• Stapedius

Which nerve innervates tensor tymoani?

trigeminal nerve(CN5) - mandibular branch

Which nerve innervates Stapedius

Facial nerve (CN7)

Which muscles limits movement and increase tension on eardrum?

Tensor Tympani

Which muscle protects oval window and decrease sensitivity to hearing

Stapedius

When will auditory tube open

yawning, swallowing

Where does auditory tube lead to

nasopharynx

What are the 2 conditions that pathogen from nose and throat to middle ear can cause

Otitis media

Mastoiditis

What are the division of inner ear

bony labyrinth

membrane labyrinth

Where is the inner ear located

petrous portion of temporal bone

what are the areas in the bony labyrinth?

semicircular canals

Vestibule

cochlea

Which area of the ear is responsible for hearing

chochlea

Which area of the ear is responsible for equilibrium

semicircular canals

vestibule

What lines the bony labyrinth

periosteum

what fluid is found in the bony labyrinth

perilympth

similar to CSF

What fluid is found in the membranous labyrinth?

endolymph

What fluid is endolymth most similar to

interstitial fluid

What is located anterior to the vestibule

cochlea

What is the spiral turns in the cochlea called?

Modiolus

What is located posterior to vestibule

semicircular canal

What are the 3 parts in the vestibular branch

ampullary

urticular

saccular

List the sequence of the transmission of sound

1. uricle directs sound waves into auditory canal

2. Soundwave strike tympanic membrane

3. Tympanic membrane vibrate

   1. Slow vibration = low frequency = low pitch

   2. Fast vibration = high frequency = high pitch

4. Vibrates Malleus > incus > Stapes

5. Oval window ( vibrates 20X vigorously)

6. Fluid pressure wave in perilymph in scala vestibuli

7. Into the scala tympani

8. Scala Vestibuli + Scala Tympani creates pressure in the emdolymph inside cochlear duct

9. Basilar membrane in endolymph vibrates = moves hair cell = produce receptor potentials

10. Generate impulses to cochlear branch of CN8

11. Signals to cochlear and superior olivary nuclei within medulla and pons

12. Midbrain ( inferior colliculus)

13. Thalamus ( medial geniculate nucleus)

14. Primary auditory area ( temporal lobe)

Low vibration = (. ) frequency/ pitch

Low

The oval window vibrates (More / Less) Vigorursly than the eardrum

More ( 20X)

Where is the perilymph?

Scala vestibuli

Where does scala vestibuli and scala tympani pass pressure to

Endolymph

What overlays the sterocilia

Tectorial membrane

Which hair cell enhance sensitivity to sound?

External hair cells

Which hair cell transform sound wave into action potential?

Inner cell

Movement of hair cells with open and close (. ) channels?

K+

Depolarization of the hair cells when (. ) chnnels open and influx of (. ) will release neurotransmitters

K+ and Ca2+

Human ear can detect sound between ____ to _____ Hz. Best between ______?

20 - 20000

Best between 1000 - 4000

Volume of sound affects the _____ of a soundwave? what is the unit

Amplitude measure be decibels(dB)

What is the conversation Hz and dB?

300 - 3000 Hz

60dB

How many dB will cause damage to ear?

85

How many dB will cause pain in the ear

120-140

Which area in the cochlea does high frequency vibrate?

Base of the cochlea

Which area in the cochlea does low frequency vibrate?

appex

Where is the primary auditory area?

temporal lobe

 

Place in order the structures involved in the visual pathway 
a) optic nerve

b) ganglion cells

c) cornea

d) lens

e) bipolar cells

f) optic nerve

g) visual cortex

h) viterous body

i)optic chaism

j) aqueous humor

k) pupil

l) photoreceptor

m) thalamus

n) Optic radiation

cornea > Aqueous Humor > Pupil > Lens > Viterous body> photoreceptor > Bipolar cell > ganglion cell > optic nerve > optic. chiasm > optic tract>thalamus>Optic radiation> visual cortex

4) The correct sequence for the auditory pathway.  

Auricle > Eardrum > Ossicles > Oval window > Cochlear > Spiral Organ

What is the partition between external auditory canal and middle ear?

Tympanic membrane

What is the oval central portion of the bony labyrinth that contains utricle and saccule

Vestibule

Which area contain hair cells which are receptor for hearing?

Spiral organ

What are the auditory ossicles

Malleus, Incus, Stapes

What contains the spiral organ?

Cochlea

What is found within the membranouos labyrinth, pressure wave in this fluid cause vibration of the basilar membrane

Endolymph

What is the opening between the middle ear and internal ear. it is enclosed by a membrane called the secondary tympanic membrane

Round window

What is the flap of elastic cartilage covered by skin that captures sound wave

Auricle

What is the fluid found inside bony labyrinth, bulging the oval window causing pressure waves

perilymph

The opening between middle and inner ear, receives base of stapes

oval window

T/F
Crista, macula, otolith and spiral organ are structure in the inner ear

True

Infection in the throat are most likely lead to ear infections in the ______

Auditory tube to the middle ear

Which is a false statement for middle ear?
A) contains ear bones called ossicles

B) related to otitis media

C) conduct sound from external ear to inner ear

D) involve cochlea

D) involve cochlea

Destruction of the left optic tract would result in

A) Blindness in left eye

B) loss left visual field of each eye

C) loss right visual field of each eye

D) loss lateral field of each eye

C) loss right visual field of each eye

Destruction of the left optic nerve would result in

A) Blindness in left eye

B) loss left visual field of each eye

C) loss right visual field of each eye

D) loss lateral field of each eye

A) Blindness in left eye

Pt detached retina of lower right portion of an eye, what is he unable to see?

object at high left

In darkness, Na+ are held open by which molecule

Cystic GMP