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Worksheets6.5 IB Neurons & Action Potentials
Total questions: 25
Worksheet time: 2hrs 57mins
The long, fiber like part of a neuron which the cell sends information to receiving neurons
axon
dendrite
axon terminal
gene
The part of the neuron that picks up stimuli from surrounding cells.
axon
axon terminal
dendrite
neuron
This insulating material forms a layer, around the axon of a neuron. It enables electrical signals to travel down the axon at higher speeds.
neuron
myelin sheath
dendrite
neurotransmitter
At resting potential, the ion distribution inside and outside of a neuron is such that __________ ions are most abundant on the outside of the cell, while __________ ions are most abundant on the inside of the cell.
Potassium; sodium
Sodium; potassium
Calcium; potassium
Calcium; sodium
In the figure above, what is occurring at step #4?
Neuron receives enough stimulation, threshold is reached
Na+ channels open allowing Na+ to diffuse inward, depolarizing the membrane
K+ channels open and Na+ channels open, action potential begins
K+ channels open allowing K+ to diffuse out, repolarizing the membrane
Na+ are being pumped out and K+ are being pumped into the cell
What is structure labeled C in the picture?
Dendrite
Axon
Cell Body
Axon Terminal
What is structure labeled B in the picture?
Dendrite
Axon
Cell Body
Axon Terminal
What is structure labeled D in the picture?
Dendrite
Axon
Cell Body
Axon Terminal
What is structure labeled H in the picture?
Nucleus
Schwann Cell
Node of Ranvier
Myelin Sheath
Which number on the graph represents the Resting Potential?
1
2
3
4
5
When a neuron is depolarized, what are the first channels to open?
Sodium gated channels
Potassium gated channnels
Sodium and potassium gated channels open at the same time
Both sodium and potassium gated channels are already open, as it is passive transport
When a neuron is resting, the inside of the axon has a ____________ charge.
positive
negative
neutral
-70 mV is the measure of the .......
Threshold Potential
Action Potential
Resting Potential
End Point Potential
A membrane potential becoming less negative is called.....
hyperpolarization
depolarization
repolarization
polarization
When a membrane potential reaches +30mV, ________ gated channels open, ________ occurs, and ________ gated channels close.
sodium, depolarization, potassium
potassium, depoloarization, sodium
sodium, repolarization, potassium
potassium, repolarization, sodium
What number on the graph represents the depolarization phase?
1
2
3
4
5
What number on the graph represents the hyperpolarization phase?
1
2
3
4
5
What number on the graph represents the refractory period?
1
2
3
4
5
Saltatory conduction is faster than regular conduction.
True
False
What does the myelin sheath do during saltatory conduction?
Allows Na+ channels to open more easily
Prevents polarization
Makes the action potential jump
Nothing
What number on the graph represents the period where active transport is occuring?
1
2
3
4
5
What is the approximate time between the start of depolarization and repolarization?
1 ms
0.5 ms
70 ms
40 ms
5 ms
What is a myelin sheath?
The part of the neuron where the action potential is generated and propagated
The part of the neuron that contains the Na+ and K+ channels
A collection of Schwann cells that allow action potentials to travel more quickly
A collection of Schwann cells that prevent an action potential
Which structure is needed for saltatory conduction?
A
E
C
F
What type of transport are depolarization and repolarization?
Diffusion
Active transport
Facilitated diffusion
Osmosis
