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Medical Phys II > Neuro Special Sensory > Flashcards

Flashcards in Neuro Special Sensory Deck (92)
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1
Q

What are the three semicircular canals?

A

Anterior
Posterior
Lateral (horizontal)

2
Q

Where are the sensory cells found in the semicircular canals?

A

Ampulla

3
Q

When the head moves to the right, which way will the hair cells bend in the ampulla?

A

Will bend to the left

4
Q

When the endolymph moves in one direction, the vestibular nerve is stimulation and tells the brain the head is moving in the ______

A

Opposite direction

5
Q

What is the area where sensory hair cells in the cochlea reside?

A

Organ of Corti

6
Q

Where are sounds with low frequency heard?

A

Apex

7
Q

Where are sounds with high frequency heard?

A

Base

8
Q

What is the round window?

A

The relief valve for fluid coming through the cochlea

9
Q

Where do ossicles articulate with the cochlea?

A

At the oval window

10
Q

Where do auditory pathway fibers enter at?

A

The medulla

11
Q

Where is the lateral lemniscus pathway (auditory) going?

A

From the brainstem to the medial geniculate nucleus in the thalamus

12
Q

What is part of the reflex center for auditory sensation, activates by having fibers descend down the spinal cord to turn head towards loud noise.

A

Inferior coliculus

13
Q

What tract sends signals from the inferior colliculus down the spinal column for a head turn reflex?

A

Tectospinal tract

14
Q

In the auditory pathway, after going to the medial geniculate nucleus, what lobe do the fibers go to?

A

Temporal lobe at transverse gyrus (where auditory sensation first comes to conscious appreciation)

15
Q

From what ear to the right hemisphere is there more input to the auditory cortex?

A

Left ear

16
Q

What type of hearing loss is the result of a mechanical transmission problem from the middle ear structures?

A

Conductive hearing loss

17
Q

What is neural hearing loss due to?

A

Destruction or degeneration of the portion of the Organ of corti or Vestibulocochelar nerve

18
Q

What hair cells are initially lost in neural hearing loss?

A

Those that get rid of extra sounds. Makes this more difficult to hear in a noisy environment

19
Q

Do patients usually detect a hearing loss with a brainstem lesion involving the auditory pathway?

A

No, because of the crossed and uncrossed nature of the pathway

20
Q

Which is the dominant auditory cortex?

A

Left superior temporal gyrus

21
Q

What does a lesion in the left superior temporal gyrus result in?

A

Inability to understand own spoken language (sensory aphasia))

22
Q

What would a lesion in the non-dominant (right) auditory cortex result in?

A

Diminished ability to locate the source and direction of sound (but won’t be deaf)

23
Q

Where do input from the vestibular system go (3 places) ?

A
Cerebellum (via inferior cerebellar peduncle)
Spinal cord (vestibulospinal tracts) 
Nuclei that regulate eye movements (Via medial longitudinal fasiculus)
24
Q

What facilitates the anti-gravity muscles?

A

Vestibulospinal tract

25
Q

What is the organizing center for directing your eyes in a particular direction. It surrounds the abducens nucleus.

A

PPRF (paramedial pontine reticular formation)

26
Q

What two structures does the medial longitudinal fasiculus connect?

A

Connects the vestibular path with the ocular nuclei

27
Q

If you move your head to the right, your eyes conjugately move to the ___?

A

Left

28
Q

What is oscillating, conjugate, slow movement of eyes in one direction followed by a rapid movement in the opposite direction. Normal response to head movement or moving visual target.

A

Nystagmus

29
Q

Which semicircular canal is very close to the tympanic membrane?

A

lateral semicircular canal

30
Q

Putting cold water into the external auditory canal causes a nystagmus in which direction?

A

Opposite direction

31
Q

Putting warm water into the external auditory canal causes a nystagmus in which direction?

A

Same direction

32
Q

What is a general term that refers to a lesion in the medial longitudinal fasiculus?

A

Internuclear opthalmoplegia

affected eye unable to adduct when other eye moves laterally

33
Q

What are the three layers of the eye from inner to outer?

A

Retina
(pigmented epithelium)
Choroid (vascular)
Sclera (connective)

34
Q

What is the pupil?

A

A hole

35
Q

Where is your vision focussed all the time?

A

Fovea

36
Q

The retina is a ___ neuron chain?

A

Three

37
Q

What neuron’s axons form the optic nerve?

A

Ganglion neurons

38
Q

What do the pigmented epithelium provide to the rods and cones?

A

Nutrients (via diffusion)

Surrond light sensitive tip so only that particular rod or cone is activated

39
Q

Why do the rods and cones need nutrients via diffusion?

A

They are avascular

40
Q

Rod and cones are continually ____

A

Renewed

41
Q

Where is the only place where the retina is attached?

A

Optic disk near the cilliary muscle.

42
Q

When a retina is detached from the choroid, what makes it worse?

A

Fluid or blood accumulation

Worse in the macula

43
Q

Do the layers of the retina extend into the fovea?

A

No- it’s only the rods and cones that are in the fovea

44
Q

If there is an increase in the ICP, where is the pressure also exerted and what does it lead to?

A

On the back of the eyeball
Can occlude blood vessels
Leads to papilledema

45
Q

What chamber is the filtration (irdial) chamber located in?

A

Anterior

46
Q

What constantly produces the aqueous humor?

A

Ciliary body epithelium (in posterior chamber)

47
Q

How does aqueous humor get to the anterior chamber and then to be drained?

A

Through the pupil into anterior angle then into filtration angle

48
Q

What does the ciliary body do?

A

Causes lens to increase/ decrease in anterior/ posterior direction (accommodation)

49
Q

What chamber is the ciliary body in?

A

Posterior chamber

50
Q

Parasympathetic innervation causes the pupil to: _______

A

Constrict

51
Q

Sympathetic innervation causes the pupil to ____

A

Dilate

52
Q

What is the most refractive structure in the eye?

A

Cornea

53
Q

What is the difference between open and closed angle glaucoma?

A

In close angle there is a physical structure that is causing glaucome

54
Q

Do the nasal or temporal retinal fibers cross?

A

Nasal

55
Q

What would a lesion in the optic chiasm result in?

A

Bitemporal hemianopsia

nasal fibers can’t cross

56
Q

What type shape is the retina?

A

Bowl-shaped

57
Q

What makes up the right visual field?

A

Temporal fibers from the right eye

Nasal fibers from the left eye

58
Q

If you have a lesion in the left retina or left optic nerve, where will you have blindness?

A

Left eye

59
Q

If you have a lesion in the optic chiasm, what will happen

A

Bitemporal hemianopsia
Temporal parts of visual fields are lost because nasal parts are responsible for temporal visual field, and they are unable to cross

60
Q

What does a lesion in the optic tract cause?

A

Homonoymous hemianopsia

Contralateral part of the visual field is lost

61
Q

Where do neurons from the eyes synapse in the cortex initially ?

A

Lateral geniculate nucleus

62
Q

Where do visual fibers end?

A

Medial aspect of the occipital lobe

63
Q

The upper part of the left visual cortex sees…..?

A

Lower part of the right visual field

64
Q

If an individual has a quadrantanopias in the right upper eye, where is the lesion most likely?

A

The left lower aspect of the temporal cortex

65
Q

What artery supplies the visual cortex?

A

Posterior cerebral artery

66
Q

Where is your interpretation of what you see occurs (lobes)?

A

Parietal lobe

Base of temporal lobe

67
Q

What artery supplies the visual association areas (temporal and parietal lobes)?

A

Middle cerebral

68
Q

What part of the visual association area interprets “where, how big, how far, motion”

A

Parietal lobe (superior)

69
Q

What part of the visual association area interprets “what, name, form, color”

A

Ventral surface of temporal lobe

70
Q

What are the two types of eye fields found in the cortex?

A

Frontal eye field

Parietal eye field

71
Q

Which eye field is continually generating saccades and searching for a target?

A

Frontal eye field

72
Q

Which eye field follows a target (ex- bird flying through air) ?

A

Parietal eye field

73
Q

Which CN provides parasympathetic innervation to the eye?

A

oculomotor nerve (III)

74
Q

What is the light reflex center of the brain?

A
Pretectal area (connect to CN III on both sides)
Allows for consensual response
75
Q

What pathway activates the sympathetic innervation to the dilator?

A

pretectal area

76
Q

If the there is a lesion in a right optic nerve, and you shin a light in the left eye, will the right even respond by constricting?

A

Yes

Oculomotor nerve to right eyes is not damaged, so it will still show indirect response

77
Q

If you have a right oculomotor lesion and you shine light in the eye, will the right eye constrict? What about the left?

A

Right eye will not constrict because the oculomotor nerve is not working (constrictor can’t be activated)
Fibers still get through to midbrain so left eye will constrict (consensual response)

78
Q

Innervation of the dilator of the pupil is a _______ function.

A

Sympathetic

79
Q

How does sympathetic nervous input get to the eye to tell it to dilate?

A

Pretectal area send axons down through brainstem into upper spinal cord where they synapse on preganglionic neurons which then synapse on a second neuron to stimulate the dilator

80
Q

What happens as a result of a lesion into the sympathetic control of the pupil?

A

Horner’s syndrome (small pupils, ptosis, diminished sweating, vasodilation)

81
Q

What is anhidrosis?

A

Diminished sweating

82
Q

Sensation from the cornea is supplied by what nerve?

A

Trigeminal

83
Q

Activation of the orbicularis oculii is by what cranial nerve?

A

Facial (VII)

84
Q

Activation of the corneal response happen by input from the cornea by way of CN ___ and output to the _______ by way of the facial nerve?

A
CN V (trigeminal) 
orbicularis oculii
85
Q

What CN opens the eye?

A

Oculomotor (III) innervating levatator palpebrae

86
Q

Which CN closes the eye?

A

Facial (VII)

87
Q

What is an arterio-venous malformation?

A

Tangle of abnormal vessels

88
Q

What would atrophy of the left medial occipital lobe lead to?

A

Right homonymous hemianopsia

89
Q

Activation of the orbicularis oculii is by what cranial nerve?

A

Facial (VII)

90
Q

Activation of the corneal response happen by input from the ______ by way of the cornea and output to the _______ by way of the facial nerve?

A

cornea

orbicularis oculii

91
Q

What CN opens the eye?

A

Oculomotor (III) innervating levatator palpebrae

92
Q

Which CN closes the eye?

A

Facial (VII)