Chapter 12 review exam questions

What are the segments of the neuron?

Receptive, Initial, Conductive, Transmissive

Which segment contains ONLY chemically gated channels?

Receptive

Which segment contains Cl- channels?

Receptive

What causes Neurotransmitters to exit a neuron?

Volt-Ca+ channels flow Ca+ into cell

What is the normal RMP of a neuron?

-70MV

What is Ohm's Law?

Voltage=Current/Resistance

At RMP what does the cytosol have in greater concentration?

K+

At RMP what does the IF have in greater concentration?

Na+

What are the 2 types of postsynaptic potentials?

EPSP + IPSP

Which postsynaptic potential make the neuron more negative?

IPSP

Which ion channels open to cause an IPSP?

K+ and Cl- channels

What is the threshold value?

-55MV

What does this cause?

Depolarization, opening of voltage-gated Na+ channels along the axon

Which way does the Na+ flow?

Into the cell

What value does the neuron depolarize to?

+30 mv

What is the inactivation state?

Short period where inactivation gates close(volt-Na+ channel), temporarily prevents their reopening

What generates an action potential?

Opening voltage gated channels along axon

When do K+ channels open?

During threshold, but they are slower and do not start to work until the end of depolarization

Which way does the K+ flow?

Out of the cell

How does this affect the membrane potential?

Makes the cell more negative (+ flows out)

What value does the cell repolarize to?

-70 mv

What is hyperpolarization?

K+ channels stay open longer than needed to reach -70mV, K+ continues to flow out and make the cell more

what value does the cell hyperpolarize to?

-80 mv

When does the Na/K pump activate?

After hyperpolarization, returns the cell to -70mV