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Flashcards in Neurons: Lec 2 Deck (135)
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1

Neurons

information processors

2

Glial Cells

Scaffolding and support services and communication facilitators

3

Anatomy of a neuron

Cell body/ soma/ perikaryon
Dendrites
Axon

4

components of the cell body/soma/perikaryon

nucleus, organelles, mitochondria, golgi apparatus, cytoskeleton, microtubules, neurofiliments

5

components of the dendrites

dendritic tree
dendritic spines

6

components of the axon

axon hillock
initial segment
node of ranvier
terminal button

7

Oligodendrocytes are myelin cell for what system

central nervous system

8

oligodendrocytes are multiple axons to 1 what

cell

9

Schwann cells are myelin cells for what system

PNS

10

schwann cells are multiple cells to 1 what

axon

11

schwann cells are speed what?

synaptic transmission

12

types of glial cells

oligodendrocytes
schwann cells
astrocytes

13

Astrocytes

star shaped cytoskeletal cells

14

three types of astrocytes

Protoplasmic
fibrous
radial

15

what are protoplasmic astrocytes

gray matter

16

what are fibrous astrocytes

white matter

17

what are radial astrocytes

development guide cells

18

Roles of the astrocytes

-structural support
-Blood brain barrier
-scar formation
-nutrient transport
-release glutamate (neurotransmitter)

19

unipolar

one cell process

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example of unipolar cells

spinal ganglia

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Bipolar

two cell processes

22

functions of bipolar

sensory

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example where bipolar cells are

retina

24

Multipolar

> 2 dendrites. many dendrites and 1 axon

25

Multipolar transmit what

sensory and motor

26

What systems are mostly composed of multipolar cells

CNS & PNS

27

pseudounipolar

afferent and efferent

28

afferent

takes info from environment to CNS

29

Efferent

takes information from CNS to muscles, glands

30

Ganglion/ ganglia

collection of cell bodies

31

Projection fibers

axon that travel up and down the CNS

32

Association fibers

axon that connect one lobe to another

33

commissural fibers

axon running between the hemispheres

34

Internuncial neurons

transmit AP from one neuron to another

35

Gray Matter

collections of nerve cell bodies
unmylinated fibers
dendtries found in CNS

36

white matter

collections of mylinated fibers

37

Fasiculas

small bundle of myelinated fibers

38

Fasiculas is synonym for what

tract in certain spinal cord sections

39

funiculus

"a little cord" composed of several fasiculi

40

funiculus differentiate what

dorsal, lateral and ventral funiculi

41

Brachium

"arm" thick bundle of fibers connecting one part of the brain to the other

42

what are synaptic triggers of action potential

-mechanical
-thermal
-chemical
-light
-electrical

43

the 3 things of a basic synaptic transmission

1. stimulus causes change in electrical potential of cell
2. threshold is reached and AP travel down axon
3. Terminal endings release chemicals that cause depolarization of next dendritic tree or cell body

44

Axon hill is the what of transmissions

gatekeeper

45

All or none phenomena

once AP fires, it is equal throughout length of axon

46

myelinated axons transmitted what than non myelinated

faster

47

fatter or skinner axons are faster?

fatter

48

voltage sensitive channels collect where

nodes of ranvier

49

voltage sensitive channels collect at nodes of ranvier, facilitating what?

saltatory conduction

50

Electrical potential as the basis for what?

synaptic transmission

51

at resting potential the cell membrane is what ?

semipermeable

52

synaptic/ receptor potentials are small areas of

depolarization

53

Depolarization

> 15 mV change required causing a rush of Na+ into channels

54

Action potential propagation continues until when

all channels are opened (cell becomes -50mV)

55

when does repolarization happen?

resting potential is reestablished

56

what is not possible during repolarization?

action potential

57

Characteristics of ion channels in cell membranes

multiple states
gating
selectivity for types and sizes of ions

58

at multiple states channels can be

either open or closed

59

voltage gate channels respond to

voltage changes

60

ligand gated channels respond to

signal molecules that land on binding sites

61

thermal gated channels respond to

temperature changes

62

mechanically gated channels respond to

deformation

63

selectivity for types and sizes of ions depend on what/

size of channel and type of molecular lining

64

absolute refractory period

intracellular charge reaches +30 - +50 mV and all Na+ channels are closed. No AP possible during this time

65

Relative refractory Period

both Na+ and K+ channels are closed causing hyper polarization .

66

During relative refractory period was cause a AP

MORE stimulus

67

Factors that affect transmission speed

-myelination
-axon diameter (larger faster)
-temp of limb (cold slow)
-age (>4 - faster)
-disease (demyelinating slow)

68

amines

small molecules / neurotransmitters

69

examples of amines

acetylcholine, catecholamines (dopamine, norepinphrine) serotonin, histamine

70

Amino acids

1-10 amines

71

examples of amino acids

glutamate, GABA, Glycine

72

Neuropeptides

large amino acid clusters

73

examples of neuropeptides

angiotensin II, B-endorphin, Cholecystokinin, corticotropin releasing factor, substance P, Enkephalin

74

Amines are creased in

presynaptic cytoplasm

75

Peptides are created in

cell body

76

Nicotinic receptors on the cell yield excitatory effect in

response to acetylcholine

77

Muscarinic receptors yield inhibitory effect in ?

response to acetylcholine

78

Acetylcholine can be what depending on the receptors

-Excitatory or inhibitory

79

Acetylcholine on skeletal muscles has what effect

excitatory

80

Acetylcholine on smooth and cardiac muscle has what effect

inhibitory

81

neurons communicate by what

chemical transmitters that cause electrical potentials

82

When does the nervous system begin to evolve

week 3

83

when does the bilaminar disc form from which nervous system will form?

14 days

84

When is their implantation ?

week 2

85

when is there further development of you sac,amnion and embryonic disc?

week 2

86

Primitive streak and groove appear where and when

in the ectoderm and week 3

87

when is there neural tube formation ?

week 3

88

Neural crest become

sensory & ANS ganglia
glands

89

Neural tube becomes

CNS, epidermis, tooth enamel

90

Notochord becomes

nucleus propulsus

91

Dermatome becomes

subcutaneous skin, sensory

92

Myotome becomes

dorsal spinal muscles

93

Sclerotome becomes

vertebral column & ribs

94

when does neural tube folding begin

week 4

95

What are the Neural tube layers

-epitheial layer
-Mantle layer
-Marginal layer
-Dorsal/alar plate
-ventral/ basal plate
-Intermediare zone

96

Gliablasts or spongioblasts (epithelial layer) becomes

-ependymal cells
-astrocytes
-oligodendrocytes

97

mantle layer becomes

gray matter

98

mantle layer sends what

neuronal process outward

99

marginal layer becomes

white matter following myelination

100

What functions does the dorsal / alar plate have

sensory

101

what functions does the ventral/ basal plate have

motor

102

What functions does the intermediate zone have

autonomic

103

what happens at week 5

cephalic folds
limbs buds appear

104

what happens at week 6

Eye
UE elbow-hand

105

What happens at week 7

acoustic meat
UE digits
foot plate

106

Prosencephalon split into

telencephalon & diencephalon

107

Telencephalon becomes what

cerebral hemispheres, corpus striatum, cortex + medullary center of white matter

108

Diencephalon becomes what

thalamus, epithalamus, hypothalamus and sub thalamus

109

Mesencephalon becomes

midbrain

110

Rhombencephalon divides into

metencephalon & Myelencephalon

111

Metencephalon becomes

pon & cerebellum

112

Myelencephalon becomes

Medulla oblongata

113

What happens at week 8?

facial features begin to form, UE and LE joints and digits have differentiated.
abdominal cavity is not complete
tail is not obvious

114

week 9-38 are considered

fetal period

115

When is a baby most vulnerable to teratogenic influences

first 2 months

116

Anencephaly

rostral neuropore does not close in 4th week

117

Spina bifida occulta

caudal neuropore does not close in 4th week, vertebral arches do not fuse

118

Meningocele

dural sack extrudes but no spinal nerve included

119

Meningomyelocele

portions of spinal cord displaced into extruding dural sack

120

Cleft palate

lack of midline closure during 6-12 weeks

121

plagiocephaly

asymmetrical skull shape

122

Brachycephaly

when baby lays on back all the time

123

Neonatal Neuronal Exuberance

-greater # of neurons are created than needed
-duplication of synaptic pathways is plentiful during development
-Synaptic connections multiply quickly
-selected cells become dormant if not used

124

Neurotophism

changes occur from the interaction of synaptically connected cells

125

during neurotophism what happens to dendrites, axon and synaptic vessel

dendritic spine proliferation
axonal myelination
synaptic vesicle development

126

What happens when neurons do not get stimulation

degrad, die or go dormant

127

What happens to cells that do not connect with enough other cells

do not receive the neurotrophic stimuli to mature

128

paring in the NS may help what

streamline communication

129

Dormant cell may be used at a later time if what happens

stimulation

130

What is neural plasticity

ability of CNS to create new pathways

131

what increases synaptic activity in the cortex and in periphery

practicing a skill

132

During an injury, what takes over for damaged tissue

adjacent cortical tissue

133

During injury, what is done to accomplish the same functional result

development of new pathways

134

what excites neurons

stimulation

135

what is related to pruning

lack of excitation