Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

BRS - neuro > Cells of the Nervous System and the Neuromuscular Junction > Flashcards

Cells of the Nervous System and the Neuromuscular Junction Flashcards

(62 cards)

Start Studying
1
Q

Unipolar neuron

A

1 axonal projection

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

Pseudo-unipolar

A

Single axonal projection that divides into two

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

Bipolar

A

2 projections from cell body

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

Multiplar

A

Numerous projections from cell body

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

Purkinje and Golgi cells

A

Multipolar GABA neurons found in the cerebellum

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

Pyramidal cell

A

Tripolar ‘pyramid’ shaped cell body

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

Neurons

A

Excitable cells of CNS
Heterogeneous morphology
Non-dividing cells

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

Soma (cell body, perikaryon)

A

Contains nucleus and ribosomes

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

Neurofilaments

A

Structure and transport

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

Axon

A

Long process (aka nerve fibre)
Sends information out from neural cell

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

What do axons branch off into

A

collaterals

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

Where do axons originate from

A

Soma at axon hillock

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

What are axons usually covered in

A

Myelin

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

Dendrites

A

Highly branched cell body - NOT covered in myelin
Receive signals from other neurons

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

What are neurons

A

Excitable cells of CNS responsible for electrical transmission

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

What are oligodendrocytes

A

Glial cells that produce myelin
Provides a substance for the axon to be more efficient

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

Astrocytes

A

Most abundant cell type in CNS
- Supportive function

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

What are microglia?

A

Neuronal macrophages

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

What are ependyma?

A

Epithelial cells lining the ventricles

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

What are the 4 major physiological ions involved in the resting membrane potential (RMP)?

A

Potassium
Sodium
Chloride
Calcium

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

How do these ions get around?

A

Cell membranes are impermeable to these ions hence transportation regulated by channels and pumps

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

What causes an uneven ion distribution?

A

Regulation by channels and pumps due to cell membrane impermeability

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

Which ions have a high extracellular concentration?

A

Sodium
Chloride

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

Which ion has a low extracellular concentration

A

Potassium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Which ion has the highest concentration gradient?
Calcium
26
What creates a potential difference across the membrane?
Difference in ion concentration
27
Describe the charge of neuronal cells
Negative charge inside compared to outside RMP of between -40 to -90mV
28
Where are the charges concentrated?
Positive and negative charges concentrated around the membrane
29
Which ions play an important role in generation of AP?
Sodium and potassium ions
30
Which channels are closed at resting membrane potential?
Voltage-gated Na+ channels (VGSCs) Voltage-gated K+ channels (VGKCs)
31
Describe what happens during membrane depolarisation
Opening of VGSC leads to Na+ influx causing further depolarisation
32
Describe what happens during membrane repolarisation
VGKCs opens at a slower rate and causes efflux of K+ from cell leading to membrane repolarisation
33
What restores the ion gradients after an action potential?
Na+K+ ATPase (pump) restores the ion gradients
34
What happens during resting configuration?
Na+ enters vestibule and upon phosphorylation ions are transported through the protein
35
What happens during active configuration?
Na+ removed from cell and K+ enters the vestibule
36
How does the pump return to resting configuration?
K+ is transported back into the cell
37
How does the AP spread along the axon
By 'cable transmission'
38
What is saltatory conduction?
when the action potential 'jumps' between nodes
39
Nodes of Ranvier
small gaps of myelin intermittently along axon
40
What does myelin do the AP and how?
Prevents AP spreading because it has high resistance and low capacitance
41
Where is the AP unable to 'jump'?
Unable to 'jump' across the gap at the axon terminal
42
Summarise neurotransmission across the synapse
1. Propagation of AP 2. Neurotransmitter release from vesicles 3. Activation of postsynaptic receptors 4. Neurotransmitter reuptake
43
What happens during propagation of the action potential?
AP propagated by VGSCs opening Sodium ion influx leads to membrane depolarisation and AP 'moves along' neurone VGKC opens leading to K+ efflux -> repolarisation
44
How are neurotransmitters released from vesicles?
AP opens voltage-gated Ca2+ channels at pre-synaptic terminal Calcium ion influx leads to vesicle exocytosis
45
How do the postsynaptic receptors get activated?
Neurotransmitter binds to receptors on post-synaptic membrane Receptors modulate post-synaptic activity
46
Describe the reuptake of neurotransmitters
NT dissociates from receptor and can either be metabolised by enzymes in synaptic cleft or recycled by transporter proteins
47
Describe the mode of communication between nerve cells (post-synaptic cell)
Autocrine and paracrine : neurotransmitter release
48
Synaptic organisation consists of what 3 things?
Axodendritic synapse Axosomatic synapse Axoaxonic synapse
49
Axodendritic synapse
Connection between presynaptic terminal to neuronal dendrite
50
Axosomatic synapse
Connection between presynaptic terminal to neuronal soma
51
Axoaxonic synapse
Connection between presynaptic terminal to neuronal axon
52
What is the neuromuscular junction?
Specialised structure incorporating axon terminal & muscle membrane allowing unidirectional chemical communication between peripheral nerve and muscle
53
What kind of communication is there between nerve and effector cells?
Paracrine : neurotransmitter release
54
Describe what happens at the neuromuscular
1. Action potential propagated along axon (Na+ and K+) -> Ca2+ entry at presynaptic terminal 2. Ca2+ entry -> acetylcholine (ACh) release into synapse 3. ACh binds to nicotinic ACh receptors (nAChR) on skeletal muscle leading to achange in end-plate potential (EPP) 4. Miniature EPP : quantal ACh release
55
Excitation-contraction coupling in the sarcolemma
Skeletal muscle membrane : nAChR activation leading to depolarisation -> action potential AP travels through T-tubules
56
Where are the T-tubules?
Continuous with sarcolemma and closely connected to sarcoplasmic reticulum
57
Where is the sarcoplasmic reticulum?
Surrounds myofibrils
58
What are myofibrils
contractile units of muscle
59
Function of sarcoplasmic reticulum
Ca2+ storage -> Ca2+ release following sarcoplasmic reticulum depolarisation Causes myofibril contraction and muscle contraction
60
What is botulism
Disorder of the neuromuscular junction Botulinum toxin (BTx) irreversibly disrupts stimulation-induced ACh release from presynaptic nerve terminal
61
What is Myasthenia Gravis (MG)
Disorder of the neuromuscular junction Autoimmune disorder in which antibodies directed against ACh receptor Causes fatigable weakness (becomes more pronounced with repetitive use)
62
Lambert-Eaton myasthenic syndrome (LEMS)
Disorder of the neuromuscular junction Autoimmune disorder : antibodies directed against VGCC

BRS - neuro (1 decks)

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