Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

CAPS 301 T1 > Neurophysiology Facts > Flashcards

Neurophysiology Facts Flashcards

1
Q

Location of hair cells in vestibular apparatus

A

On cupulla (ridge in ampulla - widening at end of loops), with base anchored to bone beneath; in cochlea (hearing), utricle, saccule

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

parasympathetic system pre- and post-ganglionic nerve length

A

preganglionic: long postganglionic: short (synapse at terminal ganglion, which may be in target organ)

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

2 requirements for an excitable cell

A

selectively permeable membrane, differential charged ion distribution

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

E_Na+

A

+60mV, goes down concentration gradient (towards inside), down electric gradient from K+ (towards inside)

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

soma location: PNS sensory neurons

A

dorsal root ganglion (just outside spinal cord)

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

Mechanism: mechanoreceptors

A

open stretch-sensitive ion channels

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

[Na+] inside cell at rest

A

15mM

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

Factor(s) contributing to membrane resistivity to electrotonic propagation

A

Number of leak channels in membrane, amount of myelin

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

Which spinal nerve does NOT carry both sensory & motor neurons?

A

C1 (uppermost; cervical 1) - only motor

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

Why is RMP closer to E_K than E_Na?

A

More potassium leak channels -> higher permeability of K+ (permeability 1:50 Na+:K+ at rest)

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

Use & meaning of I, II, III, IV classification system

A

SENSORY neuron type - based on fiber diameter I > II > III > IV

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

Semi-circular canal function

A

detect head rotation/angular acceleration of head

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

Where do hair cells in the vestibular apparatus project into?

A

Endolymph (fluid inside membrane)

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

parasympathetic neuron origin in spinal cord

A

cranial nerves and sacral region (top & bottom)

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

neuromuscular junction neurotransmitter

A

Acetylcholine

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

What is special about the fluid in the utricle & saccule vs. vestibular apparatus?

A

Topped by otolith - layer with density (and inertia) increased by CaCO3 crystals

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

State of membrane ion channel gates in stage 1 (resting) of AP propagation

A

Na+ activation: closed Na+ inactivation: open K+ activation: closed

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

reason for absolute refractory period

A

most Na+ channels have inactivation gate closed, so they are unavailable -> can’t get to threshold no matter how big the stimulus

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

What sends signals to the Medial vestibular nucleus, and where do they go from there?

A

utricle & saccule; passed on to trunk & neck for posture correction

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

type of signal propagation at nodes of Ranvier

A

active, via voltage-gated ion channels; SLOW (high membrane capacitance)

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

[K+] inside cell at rest

A

150mM

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

Threshold to open voltage-gated ion channels

A

-40mV

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

CNS excitatory neurotransmitter & receptors

A

Glutamate AMPA receptor: g_Na=g_K -> V=0mV NMDA receptor: uses Na+, K+, Ca++ (long-term changes)

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

Use & meaning of ABC classification system

A

neuron type - based on conduction velocity A(alpha>beta>gamma>delta)>B>C considers myelination, neuron diameter e.g. alpha motor neuron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
[Na+] outside cell at rest
150mM
21
State of membrane ion channel gates in stage 5 (recovery from inactivation) of AP propagation
Na+ activation: closed Na+ inactivation: open(ing) K+ activation: closed
21
Benefits of post-synaptic membrane organization in NMJ
- ACh receptors very close to ion channels -\> EPP doesn't have to travel far - lots of Na+ channels ensures V\_m reaches threshold - reliable & safe
22
Are hair cells aligned in the utricle & saccule?
no; go all directions
23
Mechanism: nociceptors, chemoreceptors, photoreceptors
G-protein coupled, indirectly open channels
24
[K+] outside cell at rest
5mM
24
sympathetic neuron origin in spinal cord
thoracolumbar region (middle)
24
Generator Potential: refractory period? graded/all-or-nothing? passive/active propagation?
no, graded, passive
26
Describe +ve feedback in depolarization
Initial depolarization increases V\_m -\> opens some Na+ channels -\> further depol -\> open more Na+ channels -\> ... -\> all Na+ channels open
27
Are hair cells aligned on the cupulla?
yes
28
directions sensed by saccule
position/movement relative to gravity: front/back, up/down
29
How is RMP established?
RMP: resting membrane potential -Na+/K+ ATPase constitutively moves ions to maintain supply -leak channels change permeability to establish RMP
31
State of membrane ion channel gates in stage 4 (AHP - After HyperPolarization) of AP propagation
Na+ activation: closed Na+ inactivation: closed K+ activation: open (closing slowly)
32
Formula for (electrotonic) length constant
lambda = sqrt(R\_m/R\_a), R\_m = membrane resistivity, R\_a = axial resistivity
33
Why is active propagation effective/efficient?
-Don't have to depolarize entire membrane -Depolarization of one segment causes electrotonic propagation, depolarizing segment further down enough to reach threshold -Individual ions don't have to travel the length of the axon
34
Where do signals from the vestibular apparatus go?
Vestibular nuclei, in brain stem
35
What sends signals to the Inferior vestibular nucleus, and where do they go from there?
all parts of vestibular apparatus; passed on to cerebellum for movement coordination
36
Structure of pre-synaptic membrane in NMJ
- vesicles of neurotransmitter (ACh) in rows (active zone); transported from soma - vesicle movement controlled by Ca++ & snare proteins
37
Structure on hair cells used to generate signal, and mechanism
kinocilium -pushed by linked stereocilia (smaller so sway easier, together move stiffer kinocilium) -opens/closes Na+/K+ gated ion channels -ion diffusion to bottom of cell opens/closes V-gated Ca++ channels -incr/decr glutamate release on Cranial Nerve VIII
37
What sends signals to the Superior vestibular nucleus, and where do they go from there?
canals of the vestibular apparatus; passed on to MLF (medial longitudinal fasciculus for eye movement coordination)
38
accessory myelin cells
Peripheral Nervous System: Schmann cells Central Nervous System: oligodendrocytes
40
How do graded (generator & other) potentials create an action potential?
Temporal or spatial summation
41
nerves used for special senses
cranial nerves
42
sympathetic system pre- and post-ganglionic nerve length
preganglionic: short postganglionic: long (synapse in ganglion just outside spinal cord)
42
State of membrane ion channel gates in stage 3 (falling) of AP propagation
Na+ activation: open Na+ inactivation: closed -\> Na+ UNAVAILABLE K+ activation: open
43
steps of synaptic transmission
1. Na+ AP reaches terminal button 2. depolarization opens V-gated Ca++ channels -\> Ca++ influx stimulates vesicle mov't to membrane 3. exocytosis of neurotransmitter 4. NT diffuses across synaptic cleft & binds receptors 5. Opens ligand-gated ion channels on post-synaptic membrane, changing V\_m (PSP); PSP attenuates via electrotonus to soma (ONLY place AP can start)
45
Structure of post-synaptic membrane in NMJ
- folded to increase surface area - ACh receptors on top of folds (close to where ACh is released) - Na+ channels (V-gated) in bottoms of folds (perijunctional zones) - ACh esterase held near here for ACh breakdown (accurate control)
46
Gate(s) on Na+, K+ channels
Na+: activation, inactivation K+: activation only
47
autonomic system neurotransmitter (between neurons)
Acetylcholine
48
Factor(s) contributing to axial resistivity to electrotonic propagation
Diameter of axon
50
systems that exert control over autonomic nervous system
spinal cord, medulla, hypothalamus, prefrontal cortex
51
Relation between signal strength from vestibular apparatuses on opposite sides of head
one increases while the other decreases, since the fluid goes the same way but the hairs are oppositely oriented ("forward" hair movement gives same change in signal, but one side moves forward & other back)
52
afferents of autonomic nervous system detect...
pressure, osmolarity, temperature, sexual stimuli, pain & stretch in viscera
53
State of membrane ion channel gates in stage 2 (rising) of AP propagation
Na+ activation: open Na+ inactivation: open K+ activation: closed (opening v. slowly)
54
Type of receptors & neurons used to sense pain & temperature
free nerve endings in skin, unmyelinated neurons (slow)
55
CNS inhibitory neurotransmitter & receptors & effect
GABA GABA\_A receptors: increase Cl- permeability; E\_Cl = -70mV (voltage clamp) GABA\_B receptors: increase K+ permeability; E\_K = -90mV (hyperpolarization) -prevents unwanted motion
58
reason for relative refractory period
some Na+ channels still inactivated (unavailable), but enough available that a large stimulus (depolarization) can open enough of them to get to threshold
59
Shape & location of vestibular apparatus
labyrinth of (3) membrane-lined loops in temporal bone, connected to cranial nerve VIII
60
location of AP (after sensor) in myelinated sensory neurons
1st node of Ranvier, NOT the soma
61
Mechanism of phasic mechanoreceptors
Pacinian corpuscule (accessory; layered & fluid-filled) wrapped around sensory nerve ending; on first pressure, puts pressure on sensory nerve (signal) b/c fluid incompressible, but fluid quickly moves away, releasing pressure (stops firing)
63
Requirement for sensory neuron to generate AP
generator potential reaches threshold
64
Into which structure do the loops of the vestibular apparatus open?
Utricle, then saccule (chambers)
65
role of sensors
signal transduction (stimulus to AP)
67
E\_K+
-90mV, concentration gradient (towards outside) balances with charge gradient (towards inside)
68
steps of signal transmission through NMJ
1. Na+ AP reaches terminal button 2. depolarization opens V-gated Ca++ channels -\> Ca++ influx stimulates vesicle mov't to membrane 3. exocytosis of ACh into synaptic cleft 4. ACh diffuses across cleft to ACh receptors 5. opens ligand-gated ion channels on motor end plate, depolarizing muscle (EPP); ACh esterase degrades ACh in synaptic cleft
69
State of membrane ion channels at rest
available
70
Acetylcholine esterase function
removes Acetylcholine from NMJ to stop signal
71
soma location: PNS motor neurons
CNS (spinal cord)
72
type of signal propagation beneath myelin layer
electrotonus (passive, FAST (low membrane capacitance))
73
Info from hair cells in utricle
head position with respect to gravity, linear side-to-side and front-to-back head movement
74
What sends signals to the Lateral vestibular nucleus, and where do they go from there?
utricle & saccule; passed on to limbs for posture correction
75
nerves used for general senses
SOMATIC: cranial V, spinal nerves except C1
76
Direction of graded potential movement
bi-directional (both ways along membrane)
78
of axon terminals per muscle fiber & result
1; must be reliable
79
What coordinates eye movement with head movement?
Vestibulo-ocular reflex (CVIII - audiovestibular, CIII - oculomotor (medial), CVI - abducens (lateral))
80
directions sensed by utricle
position/movement relative to gravity: front/back, left/right

CAPS 301 T1 (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions