Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Bio 20A > Neurons > Flashcards

Neurons Flashcards

1
Q

Dendrites

A

LOTS of little extensions off of the soma that recieve signals from other neurons

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

Soma

A

Body of a neuron
* Has a nucleus
* Protein synthesis
* Most of cells metabolism

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

Axon terminal

A

End of an axon that touches multiple other neurons

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

Axon

A

Long extension of the neuron covered with myelin

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

Synapses

A

Where the axon terminal of one neuron touches another neuron and signals it

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

Action Potential (AP)

A

Very fast electrical signal that travels down the axon from the soma to the axon terminal and can continue traveling far - When AP reaches the axon terminal → the 1st neuron fires the 2nd (at the synapse)

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

Myelin

A

Layers of fat wrapped (plasma membrane) around the axons of many neurons to Insulate and speed up AP.

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

Afferent

A

(A= ad = towards)
Sensory neurons carrying signals into the CNS from the PNS.

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

Efferent

A

(E= ex = exit)
neurons that carry info out from the CNS into the PNS

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

Motor Neurons

A

Efferent neurons that control muscles

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

Interneuron

A

Neurons that are between other neurons - almost all in the CNS

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

Multipolar Neuron

A

Most common neurons with many dendrites coming off the soma.
* Efferent neurons
* Most interneurons

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

Bipolar neuron

A

Bi-polar - 2 extensions - 1 dendrite + 1 axon
Neurons with only one dendrite coming off the soma at the end
Afferent in most of special senses:
Eyes, ears, nose

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

Pseudounipolar neurons

A

Sensory neurons where the soma is off to the side in the middle of the axon and the dendrites are at the start of the axon not coming off the soma.
AP starts where dentrites turn into axons
Somatic senses = senses of body: touch, pain, temp, tastes, etc

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

Anaxonic Neurons

A

Rare neurons only in CNS with many extensions and no clear axon.

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

Electrochemical Gradient

A

The difference in distribution of ions between 2 sides of membrane

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

Extracellular Fluid (ECF) Ions

A

Contains more Na+, Ca++, Cl-

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

Intracellular Fluid (ICF) makeup

A

More K+, amino acids + neucleotides.
Inside of the cell is negative relative to outside of the cell

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

Na+K+ Pump in relation to the electrochemical gradient

A

The most important protein for maintinaining the difference in ECF + ICF
Does active transport
Uses 1 ATP
Moves 3 Na+ from ICF → ECF
Moves 2 K+ from ECF → ICF

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

Resting membrane potential

A

The usual membrane potential of cell - when cell isn’t doing anything to change it. Has a charge of -70mV

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

Membrane potential effectors

A

Difference in concentration of ions between the fluids
Permeability of membrane to ions = how easily is if for ions to pass through the membrane

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

Open Ion Channels

A
  • Ions flow in + out of cell changing the membrane potential
  • Minimal effect on the concentration of ions on either side of the membrane
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Leak Channels

A
  • Always open protein channels
  • Mostly responsible for a resting membrane potential
18
Q

Mechanically Gated Channels

A

Opens in response to some sort of force
Ex: sense of touch

19
Ligand Gated Channel
Open when they bind a chemical Allows cells to change membrane potential in response to a chemical signal ex: Smell
20
Voltage Gated Ion Channels
Open in response to a change in membrane potential That allows changes in membrane potential to lead to more changes in the membrane potential --> Positive or negative feedback
21
Effects of more Na+ & Ca++ in the ECF
Open Na+ & Ca++ ion channels * Na+ & Ca++ flow into the cell * Makes the cell more positive
22
More K+ in the ICF
Opens K+ channels * K+ flowing out * cell is more negative
23
Polarized Membrane
membrane at resting potential: * Inside of cell is negative * Na+ & K+ leak channels open * More K+ channels open - the membrane is more negative
24
Cell Membrane Depolarization
cell becomes more positive due to: * Open Na+ or Ca+ channels * Close K+ or Cl- channels
25
Cell Membrane Repolarization
cell becomes negative again after depolarization due to: * Open K+ or Cl- channels * Close Na+ or Ca++ channels
26
Cell Membrane Hyperpolarization
Cell becomes even more negative than the resting potential (more - than -70) due to: * Open K+ or Cl- channels * Close Na+ or Ca++ channels
27
Graded Potential
A change in membrane potential that can be big or small, positive or negative Occurs in response to stimulus Bigger stimulus → bigger change Almost all cells are capable
28
Action Potential (AP)
Wave of depolarization that travels down the axon At each point down the axon - they become slightly depolarized → leads to a big depolarization → followed by a swift repolarization
29
Voltage-Gated Na+ Channel
Composed of 2 gates: 1st gate opens in response to a slight depolarization 2nd gate closes in response to big depolarization
30
Voltage-Gated K+ Channel
Opens in response to a big change (when very depolarized → repolarization)
31
Action Potential Steps
1. Resting potential 2. Threshold Depolarization 3. Depolarization 4. Repolarization 5. Hyperpolarization 6. Return to resting membrane potential
32
Resting potential for AP
Resting potential is -70mV * Leak channels are open * Voltage-gated Na+ & K+ channels are closed Membrane’s ready for an action potential
33
Threshold Depolarization
A small depolarization that’s sufficient to open volage-gated Na+ channel Na+ moves down the axon from further up the axon → Slight depolarization → reaches threshold → Voltage-gated Na+ channels open → depolarization
34
Depolarization
membrane becomes positive +40mV Voltage gated Na+ channels open -> increased permeability of Na+ -> depolarization
35
Repolarization
Membrane potential becomes negative again. When the membrane reaches +40mV: Voltage-gated Na+ channels closed Voltage-gated K+ channels open Both lead to repolarization
36
Hyperpolarization
Membrane potential overshoots - more negative than -70mV 1. Voltage gated K+ channels open to make cell negative 2. Refactory period = a new AP can’t start
37
Refactory period
A new AP can't start membrane cannot depolarize again, because K+ channels open and second gate of Na+ channel closed
38
Voltage-gated Na+ channels during action potential
Resting: Closed Depolarization: Open Repolarization: Closed Hyperpolarization: Closed
39
Voltage-Gated K+ channels during action potential
Resting: Closed Depolarization: Closed Repolarization: Open Hyperpolarization: Open
40
Action potential propagation
how an AP moves down an axon Soma → axon terminal Have an AP → Na+ enters axon from AP → Na+ diffuses down axon → slight depolarization further down the axon → threshold → starts AP Na+ will diffuse back up the axon too – further back up the axon is in Refractory period but AP can never go backwards
41
Action potential frequency
**How often a neuron has an AP** On any given neuron, all APs are: 1. Same size 2. Same speed = APs are all or nothing - binary Higher frequency APs = stronger signal
42
Myelin sheath gaps
Spots along the axon where there’s no myelin * APs happen only at gaps * No APs between where there’s myelin
43
Saltatory conduction
AP jumps from gap to gap How: 1. AP at one gap - Na+ ions flow into the cell (depolarizes the membrane) 2. Na+ ions diffuse through myelin 3. Na+ ions lead to a threshold at the next gap
44
Glial Cells
All cells in the nervous system that aren’t neurons Develop from the same tissue as neurons Located in the PNS & CNS
45
Astrocytes
Glial cells in the CNS that maintain the environment in the CNS → ion concentrations in ECF * Identifiable by the many long extensions coming off * Feed neurons * Provide structure to neurons
46
Blood-brain burrier
Hard for substances to pass from blood into the CNS Astrocytes wrap around blood vessels to help maintain the burrier
47
Oligodendrocytes
Glial cells that make myelin in the CNS Each one wraps the plasma membrane around the axons of multiple neurons
48
Microglia
Glial immune cells of the CNS * Not neural tissue * They’re WBCs that live in the CNS Phagocytes - Eat cells + large particles (Pathogens + old dead tissue)
49
Ependymal
Glial cells of the CNS that line the inside of the dorsal cavity. * Neural epithelial cells * Cerebrospinal flood on one side / Nervous tissue on the other * Cilia beat - moves Cerebrospinal fluid around the CNS * Different than other glial cells
50
Schwann cells
Glial cells that make myelin in the PNS. Each one wraps around 1 axon.
51
Satellite cells
Glial cells that wrap around cell bodies of neurons in the PNS + support them

Bio 20A (21 decks)

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