Brainscape's Knowledge GenomeTM

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


See full index

NSB Lectures > Physiology of Balance, Taste & Smell > Flashcards

Physiology of Balance, Taste & Smell Flashcards

1
Q

What is the vestibular system responsible for?

A

Balance & spatial awareness

Important in - motor coordination, response, eye movement & posture

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

Which is the primary organ of the vestibular system?

A

The inner ear

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

What are the two parts of the vestibular system?

A

Semicircular canals
Otolith organs

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

What do semicircular canals detect?

A

Angular acceleration

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

What do otolith organs detect?

A

Linear acceleration

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

What are the names of the two otolith organs?

A

Utricle and saccule

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

How are the semicircular canals arranged?

A

At 90 ° to each other - x,y & z orientation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is linear acceleration?

A

Linear motion relative to gravity

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

What detects linear acceleration?

A

Utricle and saccule

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

What are the utricle and saccule in composition?

A

Membranous sacs containing endolymph

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

What is the ionic balance of endolymph?

A

High K+
Low Na+

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

What is the sensory tissue of the utricle and the saccule?

A

The macula

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

What does the macula contain?

A

Hair cells - supported by epithelial cells.

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

What types of hair cells are found in the vestibular system?

A

Type I and Type II

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

How do the macula of the saccule and utricle lie in relation to each other?

A

At almost 90 ° to each other

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

When P is upright - which planes do the macula of the utricle and saccule lie in?

A

Utricle macula = horizontal plane

Saccule macula = vertical plane

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

What does the otolithic membrane consist of?

A

A gelatinous membrane with hair cell cilia embedded in it.

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

What detects the linear accelerational force?

A

Stereocilia of the hair cells of the otolithic membrane

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

What do the semicircular canals open into?

A

The utricle

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

Where are the sensory cells of the semicircular canals located?

A

In the ampulla of each canal (dilated end).

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

What contains the hair cells inside the ampulla of the semicircular canals?
What are they embedded in?

A

Crista ampullaris

Orientated at a right angle to the canal’s axis

Hair cells are embedded in gelatinous mass

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

What is the gelatinous mass containing hair cell cilia in the crista ampullaris called?

A

The cupula

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What types of cilia are found on hair cells in the semicircular canals?

A

Stereocilia
Kinocilium = longer stereocilia

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

How do cilia in the semicircular canals generate an AP?

A

Bending them in one direction = depolarisation
Other direction = hyper-polarisation and inhibition

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

What does movement do to the vestibular sensory receptors?

A

Creates a complex series of excitation and inhibition events - which are then interpreted by the brain as direction of movement

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

Which nerves innervate the vestibular sensory receptors?

A

Vestibular afferent nerves

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

Where do vestibular afferent nerves carry stimuli to?

A

The vestibular nuclei

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

What is the pathway of the vestibular nerves from receptors to brain?

A

Receptors via afferent nerves –> vestibular nuclei –> abducens nuclei –> trochlear nucleus –> oculomotor complex

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

What can the vestibular nuclei innervate?

A

CNS III, IV & VI (oculomotor, trochlear & abducens)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What do descending pathways from the oculomotor complex regulate?

A

Posture
Muscle tone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What can vertigo be caused by?

A

Accumulation of debris –> increase sensitivity to angular movement
Nerve / nuclei lesions
Inner ear infection & inflammation of labyrinth
Head injury
Ototoxicity
Meniere’s disease

34
Q

What are the symptoms of Ménière’s disease?

A

Intermittent vertigo
Possible hearing distortion / tinnitus

35
Q

What is Ménière’s disease caused by?

A

Accumulation of endolymph from poor drainage - endolymph oedema can cause damage to hair cells.

36
Q

How do eyes move following head rotation? What is this called?

A

Head moves one way - eyes slowly rotate in opposite as fixed in one plane of vision. This is followed by rapid eye movement towards the new direction of rotation to align with the new field of vision.

Called = nystagmus

37
Q

What is slow eye movement of head rotation controlled by?

A

Vestibular nuclei

38
Q

What is fast eye movement in the direction of rotation controlled by?

A

Brainstem (paramedian pontine reticular formation)

39
Q

What does nystagmus in the absence of head movement indicate?

A

Damage / lesion to the vestibular system

40
Q

What is the test for vestibular system damage called?

A

Caloric test

41
Q

How does the caloric test work?

A

Warm water irrigation of left ear = firing of hair cells + activation of vestibular nuclei - stimulates head movement to the left, eyes should deviate to the right.

Cold water = should not cause firing - stimulated movement should be to the right with eye movement to the left.

Absence of these expected eye movements = poss damage to the vestibular system.

42
Q

What type of receptors detect smell?

A

Chemical sensory olfactory neuron receptors

43
Q

Where are the olfactory receptors located?

A

In the mucosal epithelium of the nose.

44
Q

What is the life span of the olfactory receptors? Is this long or short?

A

30-60 days - short life span

45
Q

Where do the axons of olfactory neuron receptors project to?

A

The olfactory bulb

46
Q

What happens in the olfactory bulb?

A

The olfactory receptors synapse with second order olfactory neurons.

47
Q

What is the synapse in the olfactory bulb called? Why?

A

A glomerulus - the neurons are intertwined.

48
Q

Olfactory sensory neuron dendrites extend into what?

A

Cilia which are embedded in nasal mucosal epithelium

49
Q

What are olfactory neurons supported by? What is their function similar to?

A

Epithelial cells

Similar function to neural glial cells

50
Q

What does the basal epithelium contain that can replace the olfactory neurons?

A

Stem cells

51
Q

Are olfactory neurons myelinated?

A

No

52
Q

What do olfactory neurons synapse to form?

A

The olfactory nerve

53
Q

How do olfactory sensory neurons detect smell?

A

They contain G-protein coupled receptors.

Odorous molecules activate G-coupled proteins (inc AC, inc cAMP, cAMP opens CNGC channels - causing influx of Ca and Na, efflux of Cl = depolarisation).

Ion influx depolarises the cilia -> AP.

54
Q

What NT do olfactory sensory neurons use?

A

Glutamate

55
Q

What NT do olfactory bulb neurons release?

A

GABA & Dopamine

56
Q

What does the olfactory tract project to?

A

Olfactory cortex & entorhinal cortex - both in temporal lobe

AND

Amygdala

57
Q

Where do the olfactory cortex & entorhinal cortex project to?

A

The frontal cortex, hippocampus and hypothalamus.

58
Q

What is loss of smell called?

A

Anosmia

59
Q

What is reduction in smell called?

A

Hyposmia

60
Q

What things can cause anosmia or hyposmia?

A

Head injury (damage to olfactory bills or olfactory neurons)
Infection (damage to olfactory neurons)
Nasal polyps
Age
Alzheimer’s or Parkinsons
Smoking
Chemical exposure
Drugs
Radiation

61
Q

What is olfactory hallucination of unpleasant smells called? What can it be caused by?

A

Cacosmia (or Phantosmia)

Seizures of temporal lobe
Tumour
Parkinson’s
Head injury

62
Q

What are the five basic senses of tase?

A

Sweet, Bitter, Salty, Sour, Umami (pleasant savoury)

63
Q

Do different areas of the tongue detect different tastes?

A

No - receptors on all areas of the tongue detect each of the five senses

64
Q

What are the sensory organs of the gustatory system?

A

Taste buds

65
Q

What are taste buds interspersed amongst?

A

Different types of tongue papillae

66
Q

What are protrusions on the surface of the tongue called?

A

Papillae

67
Q

How do fluids from the oral cavity enter the taste bud?

A

Via a pore

68
Q

Do taste buds have long or short life cycles?

A

Short

69
Q

Which ganglia do the afferent taste nerves project to?

A

Ganglia of
VII
IX
X

70
Q

How do taste receptors work?

A

Chemical substances in saliva enter tase bud via pore - come into contact with microvilli

= Cascade of events (depending on substance)

= Depolarisation of the taste cells

= Release of NTs

= NTs stimulate AP in afferent neurons -> taste sensation to the brain.

71
Q

Salty substances cause an influx of which ion?

A

Na

72
Q

Sour substances cause an influx of which ion? Why do cells depolarise with sour substances?

A

Influx of H+

Depolarisation occurs due to closure of K+ channels - causing an influx of Ca

73
Q

How do sweet receptors work?

A

Sweet substance - detected by G-protein channels - inc AC, inc cAMP, inc PKA - closes K+, causes influx of Ca -> release of NTs.

74
Q

How to bitter substances work?

A

Bitter substance - detected by G-protein channel - inc PKC and IP3 -> inc of Ca -> release of NTs

75
Q

What do all taste cell pathways have in common?

A

Depolarisation by the substance opens the voltage-dependant Ca channels = influx of Ca = release of NTs

76
Q

Which NTs are released via taste receptors?

A

ATP and serotonin

77
Q

What is the gustatory pathway?

A

Chorda tympani (VII) + IX & X - project to nucleus of solitary tract and thalamus - then to the gustatory cortex.

78
Q

What is loss of taste called?

A

Ageusia

79
Q

What is partial loss of taste called?

A

Hypogeusia

80
Q

What is the sensation of unpleasant taste called?

A

Dysgeusia

81
Q

What can disruption to sense of taste be caused by?

A

Infection
Head injury
Medicine

NSB Lectures (48 decks)

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