Unit VIII - Ear Pt. 2 Flashcards Preview

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Flashcards in Unit VIII - Ear Pt. 2 Deck (70)
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31

What is the purpose of the numerous hair-like projections that project superiorward from the basilar/spiral membrane of the spiral organ?

They are sensitive to frequency and amplitude of sound waves that enter the cochlea

32

What covers the hair cells seen in the spiral organ?

Tectorial membrane

33

Where are the cell bodies located for the primary sensory neurons of the spiral organ that receive information from the receptor cells?

Spiral ganglion

34

When sound waves enter the external acoustic meatus, what structure vibrates?

Tympanic membrane

35

What structures transmit the vibrations from the tympanic membrane?

Ossicles of the middle ear (malleus, incus, and stapes, in that order)

36

What process amplifies the vibrations 1.2 times?

Transmission of vibrations through middle ear ossicles

37

What is the reason that vibrations that enter the external acoustic meatus are amplified another 17 times?

The oval window diameter is much smaller than the tympanic membrane

38

The foot of which ossicle articulates with the oval window?

Stapes

39

What forms the base of the scala vestibuli?

Oval window

40

After the vibrations are transmitted through the ossicles, where are they then transmitted?

Through the perilymph of the scala vestibuli and the scala tympani, eventually reaching the round window

41

After the vibrations are transmitted through the perilymph, what structure vibrates, and what is the result?

Basilar membrane; stimulation of receptors in the spiral organ

42

After the receptors in the spiral organ are stimulated, where is the information then transmitted?

To the cochlear nerve

43

What fluid is contained in the saccule, utricle, and three semicircular ducts?

Endolymph

44

What are the three semicircular ducts?

Anterior, lateral, posterior

45

What does the saccule communicate with?

Cochlear duct

46

Which is larger: saccule or utricle?

Utricle

47

What does the utricle communicate with?

All three semicircular ducts and the saccule

48

How does the utricle communicate with the saccule?

Utricosaccular duct

49

What are the sense organs within the utricle and saccule?

Hairlike projections called maculae

50

What bathes the maculae?

Endolymph

51

What tiny structures float on the endolymph that bathes the maculae?

Otoliths

52

What kind of action causes the otoliths to deflect the maculae and thus elicit impulses?

Movements of the head

53

Which detects centrifugal and linear in any direction accelerations: utricle or saccule?

Utricle

54

Which detects linear accelerations: utricle or saccule?

Saccule

55

What are the sense organs located within the semicircular ducts?

Crista

56

Where are the crista located in the semicircular ducts?

In the ampulla of each duct

57

What movements are the semicircular ducts sensitive to?

Accelerations in any direction, but particularly sensitive to rotational accelerations

58

Where are the cell bodies located for the neurons that carry information from the impulses that are initiated by the sense organs of the vestibular labyrinth (maculae and crista)?

Vestibular ganglion

59

What are the two branches in which the dendrites carrying information to the vestibular ganglion are collected in?

Superior and inferior branch

60

Which branch carrying information to the vestibular ganglion is larger?

Superior branch