Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Year 2 > The Ear And Hearing > Flashcards

The Ear And Hearing Flashcards

1
Q

What is sound?

A

Oscilltion of pressure through a medium such as a gas or a liquid.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is frequency?

A

Numbers of waves per second, which I can be used to determine pitch, measured in Hz. I

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the human frequency range?

A

20-20,000 Hz.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is intensity?

A

Amplitude of pressure change which can be used to determine volume.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the divisions of the ear?

A

External ear
Middle ear
Inner ear

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the external ear?

A

Region from the auricle/pinna to the tympanic membrane. It contains the external auditory meatus and is responsible for converting acoustic energy into the kinetic energy.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the function of the pinna?

A

External region of the outer esponsible for funnelling and localising sound towards the external acoustic meatus and selecting frequency of 20-100Hz. It consists of the helix, anti-helix, tragus and the lobule. The lobule is the only portion not formed of elastic cartilage.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the external auditory meatus?

A

Sigmoid canal in the outer ear to the tympanic membrane. The lateral 1/3 consists of cartilage with hair, ceruminous glands and sebaceous glands. The medial 1/3 consists of bone.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the ceruminous glands?

A

Modified apocrine glands which produce cerumen/ear wax,along with sebaceous glands.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the middle ear?

A

Air-filled chamber lined with mucous membrane located between the tympanic membrane and the oval window. Contains the ossicles and function is to convert kinetic energy into hydraulic energy.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the divisions of the middle ear?

A

Epitympanic recess
Tympanic cavity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the epitympanic recess?

A

Most superior portion of the middle ear, connected to mastoid air cells. These air cells are responsible for regulating pressure in the ear.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the ossicles?

A

Smallest bones in the body located in the middle ear which connect the tympanic membrane to the oval window.They oscillate in response to kinetic energy annd concentrate sound pressure to transmit this to the inner ear as hydraulic energy.
Malleus: attached to the tympanic membrane
Incus
Stapes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the promontory of the middle ear?

A

The promontory is a rounded hollow prominence, formed by the projection of the cochlea.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the mastoid antrum?

A

Space where the middle ear communicates with mastoid air cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the largest ossicle?

A

Malleus which is attached to the tympanic membrane at the umbo.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What does the stapes articulate with?

A

Oval window.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the function of the middle ear muscles?

A

Responsible for the acoustic reflex in response to high intensity sound. They contract and inhibit ossicle vibration to prevent damage to the tympanic membrane.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the middle ear muscles?

A

Tensor tympani and stapedius.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the stapedius muscle?

A

Acts on the neck of stapes ossicle.

Innervated by the facial nerve CNVII.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the tensor tympani muscle?

A

Acts on the handle of malleus ossicle to decrease sound transmission.

**Innervated by the mandibular branch of the trigeminal nerve (CNV)*

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the tympanic membrane?

A

Concave tissue known as the eardrum, demarcating the boundary between the outer ear and the middle ear which vibrates when it receives sound and transmits auditory information to the ossicles of the middle ear.** Especially the malleus, which is attached to the middle ear.**

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the structure of the tympanic membrane?

A

External side consists of skin and internal side consists of membrane. The membrane contains the malleus prominence, the pars reticula and pars tense. Chorda tympani passes across the tympanic membrane.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the pars tensa?

A

Portion of the tympanic membrane below the malleus prominence. It is thin because it is taut and lacks vascularisation, but contains mast cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the pars flaccida?

A

Portion of the tympanic membrane above the malleus prominence. It is well vascularised and more thicker than the pars tensa.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are the boundaries of the middle ear?

A

Roof is formed of the temporal bone.
Floor is the jugular canal.
Lateral wall is the membranous tympani.
Medial wall is the labyrinth wall.
Anterior wall is the carotid.
Posterior wall is the mastoid.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the most superior region of the middle ear?

A

Epitympanic space, connected to the malleus and the incus. This contains mastoid air cells to regulate pressure and regulate the inner ear from temperature changes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is the pharyngotympanic tube?

A

Eustachian tube connecting the middle ear to the nasopharynx which is important for equalising pressure in the middle ear and outer ear, to prevent damage to the tympanic membrane.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is the oval window?

A

Membrane in the boundary between the middle ear and the inner ear covered by the stapes. The vibrations from the tympanic membrane reach the oval window, which causes movement of endolymph fluid in the cochlea, activating receptors for hearing.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Which nerve is present in the middle ear?

A

Facial nerve and its branch, the chorda tympani which passes between the incus and malleus to innervate the anterior 2/3 of the tongue.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is the inner ear?

A

Canal between the oval window and the internal meatus that is responsible for converting sound energy into -> hydraulic energy -> electrical energy to be carried by cranial nerve 8.

32
Q

What is the cochlea?

A

Coiled Structure in the inner ear around a bony column called the modiolus. Each part of the cochlea consists of 3 segments:
Scala vestibula
Scala tympani filled with perilymph
Scala media

33
Q

What is the scala media?

A

Located above the cochlear duct filled with perilymph and part of the bony labryinth.

It contains the oval window between the middle and inner ear.

34
Q

What is the scala media?

A

Between the scala tympani and scala media, filled with perilymph rich in K+ that is part of the membranous labryrinth.

35
Q

What is the scala tympani?

A

Located below the cochlear duct filled with perilymph that is part of the membranous labyrinth. It contains the round window.

36
Q

Which part of the cochlea contains the cochlear duct?

A

Scala media/cochlea. This contains the organ of Cortis and is the only part of the cochlea filled with endolymph rich in K+.

The scala tympani and scala vestibular are filled with perilymph.

37
Q

What is helicotrema?

A

Part of the tympani where the Scala vestibuli and the Scala tympani meet, important for transmissionof low frequency sound through cochlea.

38
Q

What is Reissner’s membrane?

A

Also known as the vestibular membrane which separates the Scala vestibula and Scala media.

39
Q

What is Basilar’s membrane?

A

Separates the Scala media and Scala tympani. It contains sensory epithelium Called the organ of cortis for hearing.

40
Q

What is the organ of cortis?

A

Sensory epithelium in the basilar membrane lined with hair cells. Pressure from sound waves are transduced to electrical signals to transmit as action potentials to vestibulocochlear nerve.

41
Q

What is the composition of the cochlear hair cells?

A

Identical structure as vestibular hair cells with kinocilium and stereocilium. Outer hair cells amplify mechanical input to inner hair cells which transmits information to the sensory ganglion.

42
Q

What is the vestibule?

A

Central part of the bony labyrinth of the middle ear containing the otolith organs ; saccule and utricle.

43
Q

What is the role of the utricle?

A

Detects horizontal movements forwards and backwards.

44
Q

What is the role of the saccule?

A

Detects vertical movements up and down.

45
Q

How does sound waves travel in the cochlea?

A

Enters through the oval window and moves through the Scala vestibula and SOME travels across the Reisner membranes and when it moves across Basilar membrane, the oscillations act on the organ of cortis to transmit sound. In the Scala tympani, it moves in the opposite direction towards the round window.

46
Q

What is the difference in sound travelling in the cochlea?

A

High frequency travels to the base of the cochlea while low frequency travels to the apex at the helicotrema. There is a human frequency of 20-200Hz.

47
Q

What is tonotopy?

A

Spatial arrangement of sound travelling in the cochlea.

48
Q

What is the bony labyrinth?

A

Bony cavities formed of the petrous part of the temporal bone which contain the
Cochlea
Semicircular canals
Vestibule
It contains fluid filled canals within the bony labyrinth called the membranous labyrinth.

49
Q

What is the membranous labyrinth?

A

Ducts filled with endolymph located within the bony labryinth. There is a semicircular duct, vestibule duct and cochlear duct.

50
Q

How are the bony and membranous labyrinth separated?

A

Perilymph rich in K+.

This is also found in the scala media.

51
Q

What is the round window?

A

Part of the cochlear duct located between the scala tympani and the middle ear.

52
Q

What travels through the internal acoustic meats?

A

Cranial nerve 8: vestibulocochlear nerve and the facial nerve.

53
Q

What is the auditory cortex?

A

Located in the primary temporal gyrus. In the Lateral sulcus of the brain.

54
Q

What are the components of the auditory pathway?

A

SLIM
S: superior Olivary nucleus
L: lateral leminiscus
I: inferior colliculi
M: Medial geniculate nucleus

Decassation may occur in the superior olivary nucleus and medial geniculate nucleus, which allows the brain to receive ipsilateral and contralateral stimulation.

55
Q

What is the medial geniculate nucleus?

A

Located in the thalamus and relays information from the inferior colliculi to the primary auditory cortex. Decassate can occur here.

56
Q

What are the superior olivary nuclei?

A

Located in the brainstem for the localisation of sound.

57
Q

What is the role of the LATERAL superior olivary nuclei?

A

Detects intensity of sound, ideal for high frequency.

58
Q

What is the role of the MEDIAL superior olivary nuclei?

A

Detects timing of sound, ideal for low frequency.

59
Q

What is the auditory pathway?

A

Organ of Cortis transmits information to the ganglion of the cochlear nerve which travels to the cochlear nuclei of the brainstem at pons/medulla.
Here, the fibres will travel ipsilateral/ decassate at the superior olivary complex.

It travels up the Larteral menisci to the inferior colliculi where it decassates at medial geniculate nucleus -> primary auditory cortex.

60
Q

Where does decassation occur in the auditory pathway?

A

Most neurons will decassate at the superior olivary nucleus. Some will decassate to go back to the ipsilateral side in the medial geniculate nucleus of the thalamus. This is why the brain receives ipsilateral and contralateral auditory information.

61
Q
A
62
Q

How is sound localised?

A

Sound is localised by detecting frequency and time between sounds via the superior olivary nuclei, depending on when the sound reaches the ear.

63
Q

How is sound conducted?

A

Air conduction which is more efficient
Bone conduction that conducts sound at a low frequency, making the sound of our own voices lower.

64
Q

What are the types of hearing loss?

A

Conductive hearing loss
Sensineural hearing loss

65
Q

What is conductive hearing loss?

A

When there is an issue with sound travelling through the outer ear to the middle ear which can be due to earwax build up or otitis media.

66
Q

What is sensineural hearing loss?

A

Issue with the inner ear such as the cochlea organ of Corti, vestibulocochlear nerve or auditory cortex. This is due to congenital issue, infection with measles, mumps, rubella, ototoxic drugs such as gentamicin and

67
Q

What is the Rinne test?

A

Test to determine conductive hearing losss by testing conduction of bone vs air in the ear by placing tuning fork behind mastoid process and moving it 1-2cm away from auditory canal.

If tuning fork can still be heard= air conduction is better
If tuning fork cannot be heard= bone conduction is better

68
Q

When is the Rinne test not efficient?

A

When there is sensineural hearing loss because it equally affects bone and air conduction.

69
Q

What is the Weber test?

A

Used to distinguish between conductive and sensineural hearing loss when defective ear is known by placing tuning fork in the middle of forehead to see where sound is better.

It should be the same in both ears.

70
Q

How is sound frequency determined?

A

Position of hair cells along the basilar membrane.

71
Q

How is sound amplitude determined?

A

How much the basilar membrane vibrates, which activates ion channels in the organ of Cortis to triggers action potentials.

72
Q

What is the most medial ossicle?

A

Stapes.

73
Q

What is the most lateral ossicle?

A

Malleus

74
Q

Most common cause of otitis externa

A

Pseudomonas auerogonisa.

75
Q

Weber test: Sound is better in the affected ear?

A

Sound better in defective ear indicates conductive hearing loss due to middle ear damage or sensineural damage on the opposite ear.

76
Q

Weber test: Sound better in normal ear?

A

Sounds better in normal non-affected ear indicates sensineural damage.

Year 2 (247 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions