Nervous System** Flashcards Preview

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Flashcards in Nervous System** Deck (77):
1

What are the 3 functions of the nervous system?

Major controlling, regulatory, and communication, keeps us in touch with the internal and external environment, responsible for maintaining and regulating homeostasis

2

What are the 2 parts of the nervous system?

CNS and PNS

3

All nerves of the body residing outside of the brain and spinal cord

PNS

4

Consists of brain and spinal cord

CNS

5

Skeletal system

Somatic

6

Smooth muscle, cardiac muscles, glands

Autonomic

7

Contains the nucleus and most of the cytoplasm

Cell body

8

Projections that bring impulses into the neuron

Dendrite

9

Long projection that carries impulses away form the neuron

Axon

10

Insulating layer produced by Schwann cells

Myelin Sheath

11

Sheath formed form Schwann cells on the exterior of some axon

Neurlilemma

12

Gaps between Schwann cells

Nodes of Ranvier

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Junction between 2 communicating neurons

Synapse

14

Has many processes and part of brain or spinal cord

Multipolar neuron

15

2 processes; eyes nose, ears

Bipolar neuron

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1 process; outside the brain and spinal cord

Unipolar neuron

17

Carry impulses from the body part into the brain or spinal cord

Sensory neuron

18

Most common type of neuron that communicates from one neuron to the other; relays information

Interneurons

19

Carry nerve impulses out of brain or spinal cord to effectors (glands or muscles)

Motor neuron

20

Support neurons and phagocytize bacterial cells and cellular debris, part of the immune system

Microglial cells

21

Where are microglial cells found?

CNS

22

Provide insulating layers of myelin around axons within brain and spinal co

Oligodendrocytes

23

Structural support, join parts by their abundant cellular processes, help regulate concentrations of nutrients and ions within tissue

Astrocytes

24

Where are oligodendrocytes found?

Align along nerve fibers

25

Where are astrocytes found?

between neurons and blood vessels

26

Specialized epithelial cells in the CNS that produce CSF

Ependymal cell

27

Where are ependymal cells found?

brain and spinal cord

28

Forms a myelin sheath around axons

Schwann cells

29

Where are Schwann cells found?

PNS

30

Brings impulse to synapse

Presynaptic neuron

31

Receiving neuron at synapse

Postynaptic neuron

32

Chemical in a synaptic cleft which relays information across the gap

Neurotransmitter

33

Houses neurotransmitters

Synaptic vesicle

34

The action of the neurotransmitter on a postynaptic cell is either _______ or _____.

Excitatory or inhibatory

35

Turning a process on

Excitatory

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Turning a process off

inhibitory

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Areas of high concentration or low concentration

Gradient

38

There is an uneven arrangement of ions inside and outside the membrane of the neuron

Cell membrane potential

39

Why does a cell membrane potential occur?

There are ion pumps that for K+ into the cell and Na+ outside of the cell. There are also ion gates

40

In a resting neuron, all Na+ gates are ____(open or closed)

Closed

41

What is the result when the Na+ gates are closed?

There are more positive ions on the outside of the cell

42

What happens when there is a stimulus applied to a dendrite?

Na+ channels open

43

As the generator potential builds in the dendrite, what do the ions begin to do?

spread to the cell body and then to the initial segment of the axon

44

Chemicals that cross the synapse

Neurotransmitters

45

What do the neurotransmitters do?

Bond to receptor sites on the dendrite of the next neuron

46

How does the myelin sheath help?

Speeds up the process

47

Bring sensory information towards CNS

Afferent/sensory fibers

48

Carry impulses form CNS to effectors

Efferent/motor neurons

49

The routes that nerve impulses follow as they travel through the nervous system

Nerve pathways

50

Simplest of the nerve pathways

Reflex arc

51

Automatic Responses to a change in the environment

Reflex

52

What do reflexes help with?

Maintain homeostasis by controlling involuntary processes like heart rate, breathing rate, etc.

53

What do monosynaptic reflexes include?

2 neurons and 1 synapse

54

Reflex contraction of a muscle when an attached tendon is pulled

Stretch reflex

55

Reflexes associating with maintaining normal body posture

Postural reflex

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Involves one or more integrated neurons in the reflex arc pathway

Polysynaptic

57

Nerve cells

Neuron

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How long do neurons last?

Lifetime

59

Cluster of cell bodies in the CNS/PNS

nuclei

60

Bundle of nerve fibers running through the CNS

tracts (nerves)

61

Bundle of nerve fibers running through the PNS

Ganglia

62

What's the difference between white and gray matter?

Gray is unmyelinated while white is

63

Gradient of electrochemical potential for an ion that can move across a membrane

Electrochemical gradient

64

The difference in electrical charge between the inside and outside of an undisturbed nerve cell membrane

Resting membrane potential

65

Loss of an electric charge

Depolarization

66

Change in cell membrane making it more negative

Hyperpolarization

67

Second phase of the action potential

Repolarization

68

What is the state of sodium channels during the resting state, depolarization, repolarization, and after hyperpolarization?

Close, close, open, close

69

What is the state of channels during the resting state, depolarization, repolarization, and after hyperpolarization?

Close, open, close, close

70

How is an action potential propagated?

Na+ ions travel down the axon; resting potential, depolarization, repolarization, hyperpolarization

71

The neurons responds completely not partway through

All or nothing response

72

What variables influence the conduction velocity of a neuron?

If it is myelinated or not, thickness of axon

73

Is there an accumulation of positive or negative charges in a resting neuron?

negative

74

A drug that blocks the opening of sodium channels

Novocaine

75

What are 2 important factors that drive the movement of Na+ and K+ across the membranes?

Electrochemical and concentration gradient

76

How many Na+ ions get out of the cell?

3

77

How many K+ ions get into the cell?

2