Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Biological > 13) Nerve cells and nerve impulses > Flashcards

13) Nerve cells and nerve impulses Flashcards

(64 cards)

Start Studying
1
Q

What is found in most multicellular animal species?

A

Nervous Tissue

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

Sponges don’t have Ns but have SJs

A

Neurons/Synaptic Junctions

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

Jellyfish nervous structure

A

diffuse net nerves, no CNS

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

Bilaterians nervous structure

A

Brain and nerve cord = CNS

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

Cephalisation

A

Nervous tissue concentrated toward one end of an organism

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

CNS

A

brain and spinal cord

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

PNS

A

Peripheral NS= nerves from sense organs to the CNS

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

Nervous system microstructure

A

Nerve cells (neurons)/ Glia cells

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

Cajal & Golgi (Nobel Prize)

A

found neurons are separable (small gap between the tips of one neurons fibres and the next neuron)
The NS consists of individual neurons

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

Neurons

A

nerve cells

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

how many neurons in cerebellum?

A

70 billion

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

how many neurons in cerebral cortex

A

12-15 billion

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

how many neurons in spinal cord

A

1 billion

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

glia cells

A

glial cells
neuroglia
smaller than neurons
more frequent (x1.2)

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

three most common glia cells

A

oligodendrocytes (76%)
astrocytes (17%)
microglia (6%)

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

glia cell functions (6)

A

1- provide structure - surround neurons and hold them in place
2 - insulate nerve cells with myelin sheaths
3 - supply nutrients and oxygen to neuron
4 - removal of dead neuronal tissue & immune defence of the CNS
5 - provide scaffolding for neurons to migrate to destination during development
6 - modulate neurotransmission in the synapses

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

astrocyte function

A

provide structure by surrounding neurons and holding them in place
supply nutrients and oxygen to neuron

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

oligodendrocytes

A

CNS

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

Schwann cells

A

PNS

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

phagocyte function

A

microglia - immune defence of the CNS

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

radial glia

A

provide scaffolding for neurons to migrate to destination during development

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

name three glial cell tumours

A

glioblastoma
astrocytoma
oligodendroglioma

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

neurons def

A

cells in the NS that specialise in performing information- processing tasks

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

neuron structure

A

body cell (soma) and fibres (dendrites and axon)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
soma
cell body contains nucleus and 'machinery'
26
cell nucleus
contains genetic info of cell organized as DNA molecules
27
cell 'machinery'
mitochondria ribosomes endoplasmic reticulum golgi apparatus nissl bodies
28
mitochondria
performs metabolic activities, extracts energy from nutrients
29
ribosomes
protein production
30
endoplasmic reticulum
transports proteins to other locations
31
dendrites
branching fibres receiving information from other neurons greater surface area, more info receivable
32
where are synapses located on a dendrite
the surface - some have spines which enlarge the surface on which the synapses are placed
33
axon
thin fibre - transmits information to other neurons - axon can be 1m long
34
axon structure
distal part - branches these swell at tip and form presynaptic terminal (end bulb or bouton) some have boutons along the fibre - not just at the end
35
bouton(s)
end bulbs (swollen sections) of axon fibres - can be along as well as on the end
36
myelin sheath
insulating layer - speeds up electrical transmission
37
why are neurons diverse shapes
specialisation
38
three major types of neuron
afferent efferent interneurons
39
afferent
sensory neurons - Afferent:Arrive carry info from receptors
40
efferent
Efferent:Exit carry signals away to the effectors muscles or glands
41
interneurons
connect other neurons
42
neuronal activity
resting potential and neurons' excitation
43
Resting polarization
the membrane of a neuron maintains an electrical gradient (the difference in electrical charge) between the inside and the outside of the cell
44
resting potential
the electrical potential inside the neuron is slightly lower than outside (average - 70mV)
45
potential change (two stages)
transmission of info through neuron is realized by the change of potential 1) transmission of info from the exterior through dendrites to the cell body 2) transmission from cell body through the axon out of the neuron
46
excitation of a neuron
transmission of info within neuron is not a simple passive act at level of a neuron, there's a mechanism of analysis deciding whether to pass/block a message
47
Stages of excitation (2)
1) Dendrites Many post synaptic potentials (strong/weak changes in electrical potential) moving towards the centre Potentials from dendrites sum up 2) Cells body If sum is strong enough - the neuron fires (action potential, always the same strength)
48
2 types of synapses
excitatory/ inhibitory synapses
49
excitatory synapse
excitatory post synaptic potential. EPSP is a change in polarization moving along the dendrites towards a cell body EPSP - positive - provokes polarization (decreases polarization)
50
inhibitory synapse
IPSP change in polarization moving along dendrites to cell body IPSP - negative - provokes hyperpolarization (increases polarization)
51
what happens to postsynaptic potentials along the membrane
they become smaller and may vanish before the reaching body cell
52
summation
post synaptic potentials sum up when meet other post synaptic potentials or if followed by others
53
two types of summation
over space/ over time
54
over space summation
from different dendrites
55
over time
from the same dendrites
56
what happens to potentials in the cells body
the free potential is formed and moves toward the proximal part of the axon
57
what happens if the free potential is low (doesn't reach threshold level)
it dies
58
if free potential is high (reaches potential level)?
provokes a sudden and massive electric excitation at the proximal part of the axon: the action potential (spike)
59
process of action potential
moves along the axon without any loss in its parameters to reach the presynaptic membrane where it produces the release of chemical substance
60
all or none principle (action potential)
-amplitude of action potential is independent of amount of current which produced it - large current doesn't equal large AP -amplitude is constant for given axon (+30/40mV) - they either occur fully or not occur
61
propagation of action potential
first AP - on the axon hillock action potentials move down axon towards another cell using saltatory conduction
62
saltatory conduction
APs hop along the axon recurring at successive nodes of ranvier -> fast propagation myelin prevents any charge leakage through the axon
63
Multiple Sclerosis MS
neurological condition affecting 10k ppl in uk symptoms - vision problems/ fatigue/ difficulties with walking cause - demyelination of axons in the brain and spinal cord
64
SUMMARY
two main cells in NS - glia/neurons Neurons - perform info processing tasks Neuron basic structure - soma + dendrites + axon Neurons resting potential = -70mV stimulated neuron: if depolarisation exceeds threshold, neuron fires an action potential of a constant size

Biological (9 decks)

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