Nervous System I Flashcards

1
Q

Hyperpolarization makes the membrane potential ______ polarized

A

More

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2
Q

Two types of changes in membrane potential that transmit information

A
  1. Graded potentials

2. Action potentials

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3
Q

True or false: the amplitude of an action potential is always the same

A

True

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4
Q

Depolarize got makes the membrane potential _____ polarized

A

Less

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5
Q

A small deviation from resting potential

A

Graded potentials

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6
Q

Threshold for action potential

A

-55mV

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7
Q

Why do action potentials propagate in one direction?

A

The refractory period means that action potentials cannot travel backwards

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8
Q

Four terms used to describe direction of changes in membrane potential relative to rest

A
  1. Depolarization
  2. Overshoot
  3. Repolarization
  4. Hyperpolarization
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9
Q

The gates of a _____________ ion channel open in response to a change in membrane potential

A

Voltage-gated

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10
Q

Velocity of action potential depends on…

A

Fibre diameter and myelination

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11
Q

Two main divisions of the efferent PNS

A
  1. Somatic nervous system

2. Autonomic nervous system

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12
Q

Effectors of the somatic nervous system

A

Skeletal muscle

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13
Q

The gates of ______ ion channels randomly alternate between open and closed positions

A

Leak

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14
Q

What cells assist in regeneration of damaged neurons in the PNS?

A

Schwann cells

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15
Q

Myelinated axons have a ______ propagation speed

A

Faster

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16
Q

What type of ion channels are responsible for action potentials

A

Voltage-gated ion channels

17
Q

Four main types of ion channels

A
  1. Leak
  2. Ligand-gated
  3. Mechanically-gated
  4. Voltage-gated
18
Q

Divisions of the autonomic nervous system

A
  1. Sympathetic nervous system
  2. Parasympathetic nervous system
  3. Enteric nervous system
19
Q

The resting membrane potential of a cell at rest has a more ________ charge inside compared to the outside

A

Negative

20
Q

_____________: the force generated by the separation of charge

A

Voltage

21
Q

How do local anaesthetics such as noviciate and xylocaine prevent pain?

A

They block Na+ channels, preventing action potentials and stopping afferent pain signals reaching CNS

22
Q

Effectors of the enteric nervous system (2)

A

Smooth muscle and glands of GI tract

23
Q

The gates in a ___________ ion channel open and close in response to a specific ligand

A

ligand-gated channels

24
Q

Effectors of the sympathetic and parasympathetic nervous systems (3)

A

Smooth muscle, cardiac muscle, and glands

25
Q

How are graded potentials caused?

A

Localized ligand-gated or mechanically-gated ion channels

26
Q

Two divisions of the afferent PNS

A
  1. Somatic senses

2. Special senses

27
Q

When a charge/force has the ability to move charge, it is referred to as…

A

Potential

28
Q

Concentrations of sodium and potassium inside verses outside an excitable cell

A

High [K+]in

High [Na+]out

29
Q

_____ fibre diameter axons have faster propagation

A

Large

30
Q

Why does myelination increase propagation speed?

A

Saltatory conduction

31
Q

Order of voltage-gated K+ and Na+ opening as action potential is triggered

A

Na+ channels open as threshold is hit —> causes depolarization

K+ channels open at reversal —> causes repolarization; delayed closure causes hyperpolarization

32
Q

Gates of __________ ion channels open/close in response to a mechanical stimulation (ie. touch, pressure, tissue stretching, vibration)

A

Mechanically-gated

33
Q

Define plasticity vs repair

A

Plasticity: ability to change throughout life

Repair: regeneration after damage

34
Q

If charge is allowed to move, it is called….

A

Current

35
Q

How do Schwann cells assist in regeneration

A

Schwann cells form regeneration tube, which guides and stimulated regrow the of the axon