Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

1.1.3 The Human Body > 3. Inside the Neuron > Flashcards

3. Inside the Neuron Flashcards

1
Q

Nerve Impulse/Action Potential

A

The electrical impulse that travels between neurons to share messages
A massive momentary reversal of a neuron’s membrane potential from about -70 mV to about +50 mV

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

Action Potential Process

A

Resting Potential
Depolarization
Repolarization
Hyperpolarization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q
  1. Resting Potential
A
  • High in tension, enables neuron to react quickly to stimulation
  • Begins at resting -70mV
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q
  1. Depolarization
A
  • The charges flip, positive inside the neuron, negative outside (after threshold is reached)
  • When the right amount of stimulation is achieved (-55mV), the sodium ion channels open and Na+ ions flood the cell

Caused by the electrostatic pressure and and pressure from the concentration gradient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q
  1. Repolarization
A
  • At the peak of the sodium ion influx (+30), the sodium channels close while the potassium channels stay open (potassium ions leave)
  • Membrane potential decreases
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q
  1. Hyperpolarization
A
  • As the ions are flooding out and moving around, the neuron becomes hyperpolarized
  • Further decrease in membrane potential
    • Opposites, sodium is inside, potassium is outside
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Refractory period

A
  • After the action potential
  • Sodium channels need to close, potassium is flowing at a faster rate
  • Resists another action potential
  • Explains why the action potential can only go in one direction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Absolute refractory period

A

Membrane cannot produce an action potential

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

Relative refractory period

A

A very strong stimulus is required to generate another action potential

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

All-or-none Law

A

the action potential always has the same strength, despite any changes in strength of the stimulation

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

Rate law

A

stronger stimulation leads to more frequent action potential

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

Cause of action potential

A

The electrical impulse is caused by ions (which have an electrical charge) moving across the cell membrane

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

Membrane potential

A

difference in electrical charge inside and outside of the cell
- Caused by the unequal distributions of ions inside and outside
Sodium (Na+) and Potassium (K+) ions
- More sodium ions outside, more potassium inside (neuron is polarized)

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

Resting membrane potential

A

-70mV

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

3 causes of uneven ion distribution

A
  1. Sodium potassium pump
  2. Electrostatic pressure
  3. Pressure from concentration gradient
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Sodium potassium pump

A
  1. Takes 3 Na+ ions out, lets 2 K+ ions in
  2. This active ion transport requires energy
  3. Working during resting potential stage - maintains membrane potential
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Electrostatic pressure

A
  1. Inside of the neuron is negative, outside positive
  2. Na+ ions (outside) are drawn to the negative inside, opposites attract
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Pressure from concentration gradient

A
  1. Pressure as a result of the concentration gradient
    1. ions don’t want to be so polarized, Na+ wants in, K+ wants out
    2. Concentration gradient - concentration of particles is very high in one area and not another. Particles try to restore equilibrium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Potassium ion channels

A
  • Mostly closed during resting stage, only a few can get through
  • Leave the cell
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Sodium ion channels

A

Closed during resting stage

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

Domino effect

A
  • The action potential depolarizes nearby areas, causing more sodium channels to open
  • Each area is stimulated by the depolarization in the area near it
22
Q

Myelin sheaths

A
  • Increase the distance/reach of the action potential
    • Action potential only has to be generated at the ends of the Myelin sheaths, aka the nodes
23
Q

Nodes of Ranvier

A

Gaps between the myelin sheaths

24
Q

Saltatory conduction

A

action potential leaps between the gap
- More than 10x faster than normal conduction
- Less energy is required as fewer ions need to be transported through the membrane

25
Neurotransmitters (by size)
Amino acids Monoamines Neuropeptides
26
Amino acids
GABA - inhibitory Glutamate - excitatory
27
Monoamines
Dopamine Serotonin Norepinephrine
28
Neuropeptides
Endorphin
29
Additional neurotransmitter
Acetylcholine
30
Production & Release (amino acids & monoamines)
Amino acids & monoamines are produced at the presynaptic terminal - Both are stored in vesicles - These vesicles can then move freely
31
Production & Release (neuropeptides)
Also stored in vesicles but have to be transported to the site of release
32
Synthesis
Production of chemical compounds through reactions with simpler materials
33
Ionotropic receptors
- Similar to ion channels - neurotransmitter binds, ion-channel opens and lets ions into the cell On the side of an ion channel - Changes postsynaptic potential very fast - Used for fast events
34
Excitatory Postsynaptic Potentials (EPSPs)
A stimulating, excitatory change Increases the chance that an action potential will occur
35
Inhibitory Postsynaptic Potentials (IPSPs)
An inhibitory change Decreases the chance that an action potential will occur
36
Metabotropic Receptors
aka G-protein receptor Neurotransmitters bind, metabolic reactions are activated - Uses a G-protein & second messenger system Slower than ionotropic receptors
37
G-protein
- Activates a 'second messenger' which can - alter a metabolic pathway - change gene expression - open or close an ion channel - increase production of a certain protein
38
Endogenous chemicals
Originate outside the body e.g. neurotransmitters
39
Exogenous chemicals
Originate outside the body but can influence neurotransmitters once inside e.g. psychoactive drugs
40
Reflex arcs
stimulus - sensory neuron - muscle Goes through the spinal cord, not the brain
41
Sherrington's 3 Properties of Reflexes
1. A reflex isn't as fast as a message travelling along an axon 2. Several weak stimuli close together in position or time produce a stronger effect than one stimulus 3. One set of muscles will relax when another is excited
42
Summation
Spacial or temporal Determines the start of an action potential
43
Temporal summation
EPSPs combine in one location (or stimulate several times) to exceed the threshold and kickstart another action potential
44
Spacial summation
EPSPs in different locations (e.g. different dendrites) combine to exceed the threshold and kickstart another action potential
45
Synapse
The gap between one neuron & the next
46
Receptors
- Located in the cell membrane of the neuron - Neurotransmitters can bind here - Each receptor is 'sensitive' to specific neurotransmitters - Key-lock principle - Sub-types of receptors for each neurotransmitter
47
Presynaptic
Sends information from the end of the neuron's axon
48
Postsynaptic
Receives information form dendrites
49
Synaptic transmission
1. Neurotransmitters are held in vesicles at the axon terminal, waiting for stimulation to be released 2. Action potential causes the release of the neurotransmitters into the synapse (exocytosis) 3. Neurotransmitters bind to receptor sites, causing a change in potential 4. Reuptake - after binding and changing potential, the neurotransmitter is reabsorbed into the first neuron through uptake pumps
50
Exocytosis
Bursts of releases of neurotransmitters (or anything else in the body) from the presynaptic neuron Vesicles fuse with the membrane after releasing the neurotransmitters More vesicles are created again from the membrane (pinched off)
51
Reuptake
- Feedback mechanism - Autoreceptors on the presynaptic neuron monitor the release of neurotransmitters - Neurotransmitters bind to the autoreceptors on their original neuron as part of reuptake & a signal is released to send less of the neurotransmitter into the synaptic gap

1.1.3 The Human Body (8 decks)

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