Chapter 3 - Electric signaling

Question 1

All information/calculation is represented by?

Answer 1

electrical signals

Question 2

How do neurons generate electrical signals?

Answer 2

movement
of ions, not electrons

Question 3

What causes electrical
charges

Answer 3

Change of ion concentration gradients

Question 4

What is potential?

Answer 4

relative amount of voltage in an
electrical field

Question 5

What is a semipermeable bilayer of lipid
molecules with proteins embedded in it called?

Answer 5

Membrane

Question 6

Ion channels are selective to multiple ion true or false?

Answer 6

False - Selective to one ion

Question 7

Ion channels that open and close at specific membrane potentials?

Answer 7

Voltage-gated

Question 8

True or false, channels are distributed unifromly

Answer 8

False

Question 8

True or false, channels are distributed unifromly

Answer 8

True

Question 9

ion channels are placed by the neurons where it makes functional sense. true or false

Answer 9

True

Question 10

why are voltage-gated Sodium channels grouped?

Answer 10

so that only
certain regions of a neuron can generate action potentials.
The initial segment of axon

Question 11

where are ligand-gated channels located?

Answer 11

Postsynaptic
membranes across from the presynaptic terminals

Question 12

What is a cells resting potential?

Answer 12

cell is not responding to any
outside influences and it is not firing an impulse

Question 13

: the voltage gradient across the
membrane at steady state is called?

Answer 13

the cell’s resting
potential.

Question 14

What is the difference in potential across the
cell membrane in resting potential

Answer 14

-65 remember not 65 mV

Question 15

True or false synapse further away from the AP trigger zone have greater effect compared to closer

Answer 15

False - synapse on an axon’s initial segment has a
relatively powerful effect compared to one on a distal dendrite

Question 16

What are the 2 types of Postsynaptic potentials

Answer 16

• Excitatory postsynaptic potential (EPSP): depolarization - brings the postsynaptic element close to its threshold for firing an action potential.
  Inhibitory postsynaptic potential (IPSP): a
  hyperpolarizing response that moves the membrane away
  from the threshold

Question 17

Action Potential causes opening
of special voltage-gated ____ channels at terminal bouton

Answer 17

calcium channels

Question 18

Where is the postsynaptic terminal located?

Answer 18

usually part of a dendrite, but it can
also be located on a cell body, axon initial segment, or
another synaptic terminal

Question 19

terminal expansions of axons
(“boutons”). In some cases dendrites or even parts of cell
bodies can be ___

Answer 19

presynaptic terminals

Question 20

3 main parts of synapse

Answer 20

synaptic cleft, pre and post synaptic terminal

Question 21

What is saltatory transmission?

Answer 21

jump of AP from one node to another along a myelinated axon

Question 22

where can unmyelinated fibres be found?

Answer 22

Unmyelinated fibers are more common in the smaller nerve
fibers in the PNS

Question 23

What is the purpose of myelination?

Answer 23

ven more effective
in increasing the velocit

Question 24

True or false? the size and duration of
an action potential is different for each neuron

Answer 24

False

Question 25

What is relative refractory period ?

Answer 25

some Na+ channels open to depolarization,- the interval of time during which a second action potential can be initiated, but initiation will require a greater stimulus than before.

Question 26

Absolute refractory period corresponds to … and … whereas relative refractory period corresponds to …

Answer 26

depolarization , repolarization, hyperpolarization.

Question 27

in what period can an action potential not be generated?

Answer 27

d, Na+ channels are inactivated, absolute refractory period, N

Question 28

The membrane potential changes due to the ___ openeing at synapse?

Answer 28

Ligand-gated

Question 29

Concentration gradients are maintained by?

Answer 29

ion pumps

Question 30

Potassium equilibrium potential voltage is?

Answer 30

-94mv