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Flashcards in nervous system Deck (93):
1

afferent

sensory

2

efferent

motor

3

integrative

interneurons

4

autonomic

involuntary

5

somatic

voluntary

6

"fight or flight"

sympathetic

7

"rest and digest"

parasympathetic

8

visceral

involving organs

9

the central vervous system consists of what

brain and spinal cord

10

the peripheral nervous system consists of what

nerves and ganglia

11

What are the two major divisions of the PNS?

sensory (afferent) and motor (efferent)

12

What are the two major divisions of the motor nervous system?

somatic (voluntary) and autonomic (involuntary)

13

What are the two divisions of the autonomic nervous system?

sympathetic (fight or flight) and parasympathetic (rest and digest)

14

What is the big difference between neurons and neuroglia?

neurons send and receive electrical messages (excitable)
neuroglia support and protect neurons but don't send or receive electrical messages

15

make myelin in the CNS

oligodendrocytes

16

make myelin in the PNS

Schwann cells/neurolemmocytes

17

produce and circulate cerebrospinal fluid

ependymal cells

18

clean up dead and damaged cells in the CNS

microglia

19

most abundant and versatile glial cell, forms blood-brain barrier

astrocytes

20

surround nerve cell bodies in the PNS

satellite cells

21

short, numerous, receptive processes of neurons

dendrites

22

long, conductive process, carries impulse away from the neuron cell body

axon

23

biosynthetic center of a neuron

cell body/soma

24

chromatophilic substance, rough ER in a nerve cell body

Nissl bodies

25

bundles of fibers inside a nerve that help with structure and stability

neurofibrils

26

"aging pigment" that is a lysosomal product

lipofuscin

27

cone-shaped first part of an axon where the impulse is initiated

axon hillock

28

branches of the axon

axon collaterals

29

secretive ends of a neuron

axon terminals

30

enlarged ends of axon terminals

synaptic bulbs

31

store neurotransmitter inside synaptic bulb

synaptic vesicle

32

when things are transported from the cell body toward the axon terminals

anterograde

33

when things are transported from the axon terminals toward the cell body

retrograde

34

fatty covering over an axon that allows messages to travel faster

myelin

35

myelin sheath gaps

nodes of Ranvier

36

the lighter regions of the brain and spinal cord covered in myelin

white matter

37

the darker regions of the brain and spinal cord not covered in myelin

gray matter

38

clumps of cell bodies in the CNS

nuclei

39

clumps of cell bodies in the PNS

ganglia

40

bundles of axons in the CNS

tracts

41

bundles of axons outside the CNS

PNS

42

the exposed portion of a Schwann cell membrane

neurolemma

43

Give 2 reasons retrograde transport is significant.

allows some viruses to move to the cell body and used as a tool for introducing viruses to treat genetic disorders

44

Which structural neuron type is most common?

multipolar

45

Which structural neuron type is least common?

bipolar

46

What happens to opposite charges?

attract

47

What is needed to keep opposite charges apart?

energy

48

the difference in charge across a membrane

potential difference

49

What happens when opposite charges are allowed to come together?

energy is released

50

the unit used to measure the difference in charge between two points

volts

51

a tool to measure the difference in charge between two points

voltmeter

52

the flow of electrical charge from one point to another

current

53

the hindrance to current flow

resistance

54

the relationship between current, voltage, and resistance is shown by this

Ohm's Law

55

substances with high electrical resistance

insulators

56

substances with low electrical resistance

conductors

57

What provides resistance to current in neurons?

plasma (cell) membrane

58

the chemicals which serve as ion channels

proteins

59

channels that are always open

leakage (nongated)

60

channels that open when a specific neurotransmitter binds to it

chemically (ligand) gated

61

channels that open and close in response to changes in the membrane potential

voltage-gated

62

channels that open when receptors are physically deformed

mechanically gated

63

how ions move passively from high to low concentration and toward opposite charges

electrochemical gradient

64

the difference in charge on either side of a resting neuron membrane

resting potential

65

having opposite charged ends or sides

polarized

66

a loss of charge difference

depolarization

67

an increase in membrane resting potential, the inside becomes more negative

hyperpolarization

68

a local change in membrane potential, magnitude varies with signal strength

graded potential

69

the minimum stimulus needed to cause a response

threshold

70

a weak stimulus that doesn't cause a response

subthreshold

71

when the message is sent along the axon

propagated

72

the nerve either sends the message or doesn't, nothing in between

all-or-none phenomenon

73

the time when a neuron can not respond

absolute refractory period

74

the time when the threshold stimulus is greatly elevated

relative refractory period

75

How are the gates arranged when the neuron is resting?

all closed

76

What gates open to depolarize the membrane and send the action potential

Na+

77

What gates open to repolarize the membrane?

K+

78

a nerve impulse, long-distance signal

action potential

79

What is the purpose of graded potentials?

cause action potentials

80

What 2 factors affect the speed of a nerve impulse?

diameter of fiber and amount of myelin

81

slow impulse conduction in unmyelinated fiber

continuous

82

fast impulse conduction in myelinated fibers

saltatory

83

an autoimmune disease characterized by hardened lesions on the myelin sheaths

multiple sclerosis

84

large diameter fibers with thick myelin, fastest

Group A

85

small, unmyelinated fibers, slowest

Group C

86

medium thick fibers with light myelin

Group B

87

quick successive stimuli summate to increase the amplitude of a graded potential

temporal summation

88

multiple stimuli at different locations increases the amplitude of a graded potential

spatial summation

89

immature nerve cells

neuroblasts

90

What happens to most neuroblasts

die if don't make good connections

91

Why are most tumors of the nervous system gliomas?

neurons are so specialized that they have lost the ability to divide

92

What three things disrupt nerve messages?

local anesthetics block Na channels
cold and pressure disrupt blood flow

93

What ions are responsible for the resting potential or charge difference in a resting neuron?

Na+ and K+