Neuronal Physiology

Question 1

What are excitable Tissues

Answer 1

Tissues that produce electrical signals by drastically altering their resting membrane potential briefly

Question 2

Depolarization

Answer 2

decrease in potential; membrane less negative

Question 3

Repolarization

Answer 3

return to resting potential after depolarization

Question 4

Hyperpolarization

Answer 4

increase in potential; membrane more negative

Question 5

What affects the strength and length of graded potentials?

Answer 5

Stimulus strength

Question 6

What affects the degree to which a graded potential will spread? Do they spread far?

Answer 6

Resistance, they do not spread far

Question 7

What are some features of action potentials?

Answer 7

Self-propagating, Nondecremental, may be initiated by graded potentials

Question 8

Do Sodium and Potassium pumps maintain the concentration gradient?

Answer 8

Yes

Question 9

What happens once AP is initiated at the Axon Hillock

Answer 9

It travels down the Axon away from the cell body

Question 10

How can action potential travel ?

Answer 10

Contiguous Conduction, Continuous movement, Saltatory Conduction, AP jumps along Axon because of myelin

Question 11

What occurs during contiguous conduction?

Answer 11

it is the second way of nerve impulse transmission

Question 12

Where does contiguous conduction occur?

Answer 12

Unmylinated axons

Question 13

How is it possible for AP to form on the axon?

Answer 13

Due to the opening of sodium and potassium channels

Question 14

Do graded potentials spread passively?

Answer 14

Yes

Question 15

What is saltatory conduction

Answer 15

an electrical impulse skips from node to node down the full length of an axon, speeding the arrival of the impulse

Question 16

Synapse

Answer 16

the junction of two neurons, the junction between a neuron and a target cell

Question 17

Excitatory Post-Synaptic Potentials

Answer 17

synaptic inputs that depolarize the postsynaptic cell, bringing the membrane potential closer to threshold and closer to firing an action potential.

Question 18

How are Excitatory Post-Synaptic Potentials produced

Answer 18

by opening Na+ and K+ channels, similar to the nicotinic ACh receptor.

Question 19

Inhibitory Post-Synaptic Potentials

Answer 19

temporary hyperpolarization of postsynaptic membrane caused by the flow of negatively charged ions into the postsynaptic cell

Question 20

When is a IPSP received

Answer 20

When an inhibitory presynaptic cell, connected to the dendrite, fires an action potential.

Question 21

Grand postsynaptic potential

Answer 21

the total potential in the postsynaptic neurons.

Question 22

Temporal Summation

Answer 22

the summation in the nervous system in which a single presynaptic neuron involves in the production of multiple subthresholds over a period of time.

Question 23

spatial summation

Answer 23

sensory summation that involves stimulation of several spatially separated neurons at the same time.

Question 24

presynaptic inhibition

Answer 24

an inhibitory neuron provides synaptic input to the axon of another neuron (axo-axonal synapse) to make it less likely to fire an action potential.

Question 25

Convergence vs divergence

Answer 25

Divergence allows one neuron to communicate with many other neurons in a network. Convergence allows a neuron to receive input from many neurons in a network