Brainscape's Knowledge GenomeTM

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


See full index

Neurology > Neurophysiology > Flashcards

Neurophysiology Flashcards

1
Q

what is the node of ranvier

A

gap in myelin sheath on the axon of certain neurons

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

What is the axon hillock and initial segment

A

site of initiation of the ‘all or none’ action potential

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

local interneurone

A

e.g. between neurones in CNS

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

3 types of neurone

A

sensory
motor
interneurone

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

what causes the upstroke/rapid depolarisation of the neurone action potential

A

voltage gated sodium channels open, allowing sodium influx

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

what causes the downstroke of neurone action potential

A

potassium leaves cell and sodium channels inactivate

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

why do passive cells not spread far from their site of origin?

A

the nerve cell membrane is ‘leaky’ (imagine the axon is a leaky garden hose)

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

what is the relationship between the diameter of axons and the resistance

A

the bigger the diameter, the lower the resistance, so faster conduction

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

strategies to increase passive current speed

A
  • increase axon diameter
  • myelin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is myelin produced by?

A

Schwann cells in PNS
Oligodendrocytes in the CNS

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

is conduction faster in myelinated or nonmyelinated axons of the same diameter

A

myelinated

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

name 2 demyelinating disorders

A
  • multiple sclerosis (CNS)
  • Guillain-Barre syndrome (PNS)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what are the 8 steps of chemical neurotransmission

A
  1. uptake of precursor
  2. synthesis of transmitter
  3. storage of transmitter
  4. depolarisation by action potential
  5. Ca2+ influx through voltage-activated Ca2+ channels
  6. Ca2+ induced release of transmitter (exocytosis)
  7. Receptor activation
  8. Enzyme-mediated inactivation of transmitter or reuptake of transmitter
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

where are vesicles found and what do they store

A
  • presynaptic terminal
  • neurotransmitter
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

acetylcholine, amino acids and amines are released from _______ vesicles

A

synaptic

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

peptides are released from ______ vesicles

A

secretory

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

do inotropic ligand-gated ion channels mediate fast or slow neurotransmission?

A

fast

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

do metabotropic G-protein-coupled receptors mediate fast or slow neurotransmission?

A

slow

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

direct gating is by ______ receptors

A

inotropic

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

indirect gating is mediated by activation of _________ receptors

A

metabotropic

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

AMPA and kainate are examples of which type of receptors

A

Non-NMDA
(fast)

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

What are non-NMDA receptors?

A

a class of ionotropic glutamate receptors found in the CNS

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

do NMDA receptors contribute a slow or a fast component to the excitatory synaptic potential

A

slow

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

what is the main inhibitory neurotransmitter in the CNS

A

GABA

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

What 2 types of receptors does GABA act on

A
  • inotropic GABA A receptor
  • metabotropic GABA B receptor
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

are these neurotransmitters excitatory or inhibitory:
a) glutamate
b) GABA

A

a) excitatory
b) inhibitory

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

where are purkinje cells found

A

cerebellum

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

where are the inhibitory basket cells commonly found

A
  • cerebellum
  • hippocampus
  • cortex
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

what is the calyx of held synapse

A

a giant terminal, something to do with the auditory system

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

true or false, a neurone typically has multiple synaptic contacts from multiple cells

A

true

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

what is transduction

A

conversion of physical stimulus into electrical signal

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

For a sensation to arise, what four events typically occur?

A
  1. stimulation of the sensory receptor
  2. transduction of the stimulus
  3. generation of nerve impulses
  4. integration of sensory input
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

graded potentials (not APs) vary in amplitude depending on what?

A

the strength of the stimulus that causes them

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

what do nociceptors respond to

A

painful stimuli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

which sensory receptors detect chemicals in the mouth (taste), nose (smell) and body fluids

A

chemoreceptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

what do osmoreceptors detect?

A

the osmotic pressure of body fluids, particularly the concentration of dissolved ions and solutes, such as sodium and glucose, in the blood and CSF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Where does the pyramidal corticospinal pathway originate

A

Motor cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Lateral corticospinal tract - where do upper motor neurons decussate

A

Pyramids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Anterior/ventral corticospinal tract - where do upper motor neurons decussate

A

Levels of spinal cord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Which spinal tract regulates fast and fine (skilled) movements

A

Corticospinal (lateral and anterior/ventral)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What does a lower motor neuron connect?

A

Upper motor neuron to the skeletal muscle it innervates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Where does the cell body of a LMN lie?

A

Within the ventral horn of the spinal cord or the brainstem motor nuclei of the cranial nerves which have motor modalities

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

LMNs exit spinal cord via _________ roots

A

Ventral/anterior

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

The anterior/ventral corticospinal tract is responsible for the control of the ___________ musculature

A

Proximal

45
Q

The lateral corticospinal tract is responsible for the control of the __________ musculature

A

Distal

46
Q

Where do UMNs originate
a) in the pyramidal tracts
b) in the extrapyramidal tracts

A

a) cerebral cortex
b) within nuclei in the brainstem

47
Q

What tracts are included in ‘extrapyramidal motor tracts’

A
  • rubrospinal
  • reticulospinal
  • vestibulospinal
  • tectospinal tracts
48
Q

What do extrapyramidal motor tracts regulate

A
  • axial muscles that maintain balance and posture
  • muscles controlling coarse movements of the proximal portions of limbs
  • head, neck and eye movement
49
Q

Where does the rubrospinal tract originate

A

Red nucleus of the midbrain

50
Q

What would excitation of the rubrospinal tract typically cause

A

Excitation of flexor muscles
Inhibition of extensor muscles

51
Q

Where do the vestibulospinal tracts originate

A

Vestibular nuclei

52
Q

Which type of tract is involved in posture, and in supporting the body against force of gravity, mainly targeting extensors

A

Vestibulospinal

53
Q

Where do the tectospinal tracts originate

A

Superior colliculi (paired structures located in the midbrain of the brainstem)

54
Q

What do the tectospinal tracts mediate

A

Orienting towards visual targets

55
Q

Where does the reticulospinal tract originate

A

Reticular formation

56
Q

What is the reticular formation

A

A diffuse collection of neurons in the pons and medulla where the reticulospinal tract originates

57
Q

The reticulospinal tract is involved in balance, true or false

A

True

58
Q

What are betz cells

A

Upper motor neurons that send their axons down to the spinal cord via the corticospinal tract

59
Q

Of the three motor cortex areas, stimulation of which area requires the least amount of electrical current to elicit a movement

A

Primary motor cortex

60
Q

What can primary motor cortex neurons encode?

A

The force of a movement
The direction of a movement
The extent of a movement
The speed of a movement

61
Q

What are 3 forms of pain

A

Nociceptive
Inflammatory
Pathological

62
Q

What does PAG stand for

A

Periaqueductal grey

63
Q

what do low threshold mechanoreceptors mediate

A

touch, vibration, pressure

64
Q

what do high threshold mechanoreceptors (aka mechanical nociceptors) respond to

A

high intensity mechanical stimuli

65
Q

what do chemical nociceptors (chemoreceptors) respond to

A

substances in tissue e.g. prostaglandins, bradykinin, serotonin, histamine, K+, H+ and ATP and many others.
play a crucial role in pain

66
Q

alpha fibres

A

first fast pain.
stabbing

67
Q

c fibres

A

second slow pain

68
Q

are alpha fibres myelinated or unmyelinated

A

thinly myelinated

69
Q

are c fibres myelinated or unmyelinated

A

unmyelinated

70
Q

nociceptive c and Adelta fibres mostly terminate superficially in which laminae?

A

I and II
also V for Adelta fibres

71
Q

where does perception of light signal occur

A

cortex

72
Q

direction of signal in the retina

A

photoreceptors —> bipolar cells —-> ganglion cells

73
Q

horizontal cells

A

a type of specialized neuron found in the retina of the eye

receive input from photoreceptors and project to other photoreceptors and bipolar cells

74
Q

direction of light in retina

A

ganglion cells —> bipolar cells —> photoreceptors

75
Q

where does the light signal go after the ganglion cells

A

makes its way through optic nerve to cortex via lateral geniculate nucleus

76
Q

each photoreceptor has its own receptive field, true or false

A

true

77
Q

which photoreceptor is more numerous

A

rods

78
Q

which photoreceptors help you see in dim light

A

rods

79
Q

a single ganglion cell only receives signal from from rod cell, true or false

A

false - many rods will send their signal onto a single ganglion cell

80
Q

what happens when a photoreceptor detects light

A

it stimulates G-protein coupled receptor which activates cGMP

81
Q

what photoreceptor is best. seeing in daylight

A

cones

82
Q

where are cone cells most numerous

A

fovea

83
Q

is there more convergence in cone or rod system

A

rod
(increasing sensitivity, while decreasing acuity)

84
Q

what are the 3 types of cones

A

short-wave
middle-wave
long-wave

85
Q

which has high visual acuity, rod or cone cells?

A

cones

86
Q

what does center-surround organisation/lateral inhibition do

A

serves to emphasise areas of contrast i.e. it sharpens the boundary between objects of different luminance

(when a neuron is activated, it not only sends signals to the brain but also inhibits the activity of neighboring neurons. This inhibition serves to sharpen the contrast between the stimulated neuron and its neighboring neurons)

87
Q

what is the striate cortex

A

the part of the visual cortex that is involved in processing visual information

88
Q

hearing: a brief overview

A
  1. sound —> vibration of air
  2. vibrate the eardrum, the malleus, the incus, and the stapes
  3. the vibration spreads to the cochlea
  4. vibration of air is converted to movement/vibration of fluids in the cochlea
  5. the vibration in the cochlea is captured by hair cells
  6. transduction (physical vibration is transduced to neural energy)
  7. perceived in the auditory cortex
89
Q

a) where is reissner’s membrane?
b) what does it separate?

A

a) inside the cochlea, inner ear
b) scala media from scala vestibuli

90
Q

a) where is basilar membrane?
b) what does it separate?

A

a) inside the cochlea, inner ear
b) scala media from scala tympani

91
Q

where do scala tympani and scala vestibuli connect

A

helicotrema

92
Q

where does amplification occur in the ear

A

middle ear (through banging of the stapes, and added force from buckling of the tympanic membrane

93
Q

where are hair cells located

A

organ of corti in the cochlea

94
Q

what are the 2 types of hair cell

A

inner and outer

95
Q

which of the scala contain perilymph and which contain endolymph

A

scala vestibuli - perilymph
scala media - endolymph
scala tympani - perilymph

96
Q

a) inner hair cell function
b) outer hair cell function

A

a) detect sound and transmit it to brain

b) perception of sound. Amplifer

97
Q

interesting fact about the sodium/potassium levels in endolymph

A

higher K concentration than normal. K comes into the cell! (normally goes out)
lower Na than normal

98
Q

what do hair cells of the ear sit on

A

basilar membrane

99
Q

VIII nerve: branches —> 3 cochlear nuclei:

A
  • Dorsal Cochlear Nucleus (DCN)
  • Posteroventral Cochlear Nucleus (PVCN)
  • Anteroventral Cochlear Nucleus (AVCN)
100
Q

auditory system super basic pathway

A

cochlea –> brainstem —> cortex

101
Q

what does tonotopy mean

A

The spatial arrangement of where sound is perceived, transmitted, or received.

102
Q

what is the function of the semicircular canals

A

detect head movements via rotatory acceleration

103
Q

what are the semicircular canals filled with?

A

endolymph

104
Q

what do the otolith organs do?

A

sense linear acceleration and gravity

105
Q

what are the two otolith organs

A

utricle (movement in the horizontal plane)
saccule (movement in the vertical/sagittal plane)

106
Q

what are the 3 major vestibular reflexes?

A
  • vestibulo-ocular
  • vestibulo-colic
  • vestibular-spinal
107
Q

which vestibular reflex keeps the eyes still in space when the head moves

A

vestibulo-ocular

108
Q

which vestibular reflex keeps the head still in space or on a level plane when you walk

A

vestibulo-colic

109
Q

which vestibulo reflex adjusts posture for rapid changes in position

A

vestibulo-spinal

Neurology (12 decks)

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