Nerve Conduction and Synapse Transmission Flashcards Preview

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Flashcards in Nerve Conduction and Synapse Transmission Deck (33):
1

What are Dendrites?

They receive inputs from other neurones and convey graded electrical signals passively to the soma

2

What is the Soma? (Perikaryon)

Synthetic and metabolic centre.

3

What does the Soma contain?

The nucleus
Ribosomes
Mitochondria
ER/RER

4

What happens at the Axon hillock and initial segment?

All or nothing action potential

5

What does the Axon do?

Conducts the output signals as action potentials to other neurones
mediates transport of materials between soma and presynaptic terminal

6

What is the synapse?

Point of chemical communication between neurones

7

Give an example of a unipolar neurone

peripheral autonomic neurone

8

Give an example of a pseudounipolar neurone

Dorsal root ganglion (DRG)

9

Give an example of a Bipolar neurone

Retinal Bipolar neurone

10

Give an example of a Multipolar neurone

Lower Motor neurone (LMN)

11

What causes the upstroke in an action potential?

Voltage-activated Na+ channel

12

What causes the downstroke in an action potential?

Voltage gated K+ channel

13

How big may an axon be?

Up to 1 metre

14

The distance over which a current spreads depends upon what?

membrane resistance
Axial resisitance (axoplasm)

15

True or False:
The longer the length in constant, the greater the local current spread?

TRUE

16

What does a Schwann cell surround?

A single axon

17

What does a Oligodendrocyte surround?

many axons

18

What is the name of the node that the action potential jumps from one to another?

Ranvier

19

In the CNS, what is the most common excitatory transmitter?

Glutamate

20

What are the excitatory and inhibatory responses?

Excitatory = depolarizing
Inhibatory = hyperpolarizing

21

In the CNS, what is the most common inhibatory transmitter?

Gamma-Aminobutyric acid (GABA)
or
Glycine

22

What do the excitatory transmitters activate?

Postsynaptic cation sleective ionotrophic glutamate receptors

23

What do the inhibatory transmitters activate?

Posysynaptic anion selective ionotrophic receptors

24

What does e.p.s.p stand for?

Excitatory postsynaptic Potential

25

WHat does i.p.s.p stand for?

Inhibatory postsynaptic potential

26

What holds the pre and post synaptic cleft together?

A matrix of fibrous extracellular protein within the cleft

27

What receptors are involved in the excitatory process?

Sodium

28

What receptors are involved in the inhibatory process?

Chlorine

29

What happens in Spatial Summation?

Many inputs converge upon a neurone to determine its output

30

What happens in Temporal summation?

A single input may modulate output by variation in action potential frequency of that input

31

Where are amino acids and amines released from?

Synaptic vesicles

32

Where are peptides released from?

Secretory vesicles

33

How are enzymes transported in the body?

By axoplasmic transport along microtubules to the presynaptic terminal