Neurones; Communication between them (NB 020)

Question 1

Answer 1

Question 2

Answer 2

Question 3

Answer 3

Question 4

Answer 4

Question 5

Definition of Synapses ?

Answer 5

The site of contact between 2 neurons or 2 cells without protoplasmic continuity

Question 6

Answer 6

Question 7

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Question 8

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Question 9

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Question 10

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Question 11

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Question 12

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Question 13

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Question 14

Answer 14

Question 15

Answer 15

Question 16

Compare Spatial and Temporal summation in terms of :
-which is most common
- how they occur
-can both accure at same time ?

Answer 16

Question 17

Compare Action potential and Postsynaptic potentials in terms of :

-effect on membrane negativity

• all or none law ?
• grading

-refractory periods ?

-summation

-propagation

-duration

Answer 17

Question 18

How is the Postsynaptic response graded ?

Answer 18

Question 19

What determines the resistance of the membrane Rm ?

Answer 19

Question 20

Answer 20

Question 21

Define Synaptic delay

Answer 21

time passed between arrival of the impulse at presynaptic terminal till excitation of postsynaptic neuron).

Question 22

Why does Synaptic fatigue happen ?

Answer 22

due to depletion of the neurotransmitter vesicles.

Question 23

Define Synaptic plasticity

Answer 23

change in synaptic transmission which may be increase (potentiation) or decrease (inhibition) for short or long term.

Question 24

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Question 25

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Question 26

Define Convergence and mention it’s function

Answer 26

Question 27

Define Divergence and mention it’s function

Answer 27

Question 28

What happens at the Excitation field ?

Answer 28

all the neurons in the pool are excited by a single input.

Question 29

What happens at the Discharge zone ?

Answer 29

the central neurons in the excitation field.

They receive large number of presynaptic terminals&raquo_space; summation of many EPSP&raquo_space; they can reach to firing level and discharge impulses.

Question 30

What happens at the Facilitated zone (subliminal fringe) ?

Answer 30

the peripheral neurons in the excitation field, receive small number of presynaptic terminals&raquo_space; summation of less EPSP&raquo_space; they can not reach to firing level and discharge impulses but they are only facilitated.

Question 31

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Question 32

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Question 33

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Question 34

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Question 35

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Question 36

Definition and mechanism of Fatigue in the neuironal pool ?

Answer 36

Question 37

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Question 38

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Question 39

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Question 40

Answer 40