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Flashcards in Neurophysiology, Topnotch Deck (158):
1

Functions of astrocytes

1) Regulate ECF ion levels
2) Mechanical support
3) Forms BBB

2

Creates myelin in CNS

Oligodendrocytes

3

Creates myelin in PNS

Schwann cells

4

Brain tumors from immature neurons (2)

1) Neuroblastoma
2) Retinoblastoma

5

Where action potential in a neuron starts

Axon hillock

6

Branches of axons

Neural fibrils

7

Terminal portion of neural fibril that contains NT-containing vesicles

Axon buotons

8

Part of a synapse where there is a high density of mitochondria

Presynaptic terminal of a cholinergic neuron

9

Where K channels are highly concentrated

Paranodal axolemma and Schwann cell membrane

10

Death of axon distal to site of injury

Wallerian degeneration

11

CNS vs PNS: Where axonal regeneration occurs better

PNS

12

Sites of ACh secretion (5)

1) Nucleus basalis of Meynert in basal ganglia
2) Large pyramidal cells in motor cortex
3) All preganglionic neurons of ANS
4) Postganglionic PSY neurons and postganglionic SY of sweat glands
5) Skeletal muscles

13

ACh synthesis

Acetyl CoA + choline catalyzed by choline acetyltransferase

14

Main neurotransmitter in REM sleep

ACh

15

ACh degradation

Acetate + choline catalyzed by acetylcholinesterase whereby choline is recycled

16

ACh is deficient in what disease entity

1) Alzheimer's disease
2) Huntington's disease

17

Dopamine is deficient in what disease entity

1) Parkinson's disease
2) Depression

18

Main sites of dopamine (2)

1) Substancia nigra pars compacta
2) VTA

19

Enzymes that degrade dopamine

1) MAO in presynaptic nerve terminals
2) COMT in tissues

20

What hormone is in excess in Schizophrenia

Dopamine

21

Sites of NE and Epinephrine secretion (4)

1) Locus ceruleus in pons
2) Brainstem
3) Hypothalamus
4) Postganglionic SY except sweat glands

22

Phenylalanine derivatives

1) Tyrosine
2) L-dopa
3) Dopamine
4) NE
5) Epinephrine
6) Thyroxine
7) Melanin

23

Tryptophan derivatives

1) Melatonin
2) Serotonin
3) Niacin

24

Tyrosine --> L-dopa enzyme

Tyrosine hydroxylase

25

L-dopa --> Dopamine enzyme

Dopa decarboxylase

26

Dopamine --> NE

Dopamine b-hydroxylase

27

NE --> Epinephrine

Phenylethanolamine-N-methyltransferase

28

Also known as the happy hormone

Serotonin

29

Main site of serotonin secretion

Median raphe of brain stem

30

Where serotonin is secreted to initiate sleep

Median raphe of brain stem

31

Where serotonin is secreted to inhibit pain pathways

Spinal cord

32

Degradation of serotonin

5-HIAA catalyzed by MAO + aldehyde dehydrogenase

33

Conversion of serotonin

Melatonin in pineal gland

34

NT responsible for long-term memory

NO

35

NO is synthesized from

Arginine

36

Stimulatory vs inhibitory: NO

Inhibitory

37

Difference of NO from other NTs

Not preformed and stored in vesicles

38

NT involved in ctrl of arousal, sleep, and circadian rhythm

Histamine

39

From which histamine is synthesized

Histidine

40

Histamine is secreted mainly in

Tuberomamillary nucleus of hypothalamus

41

Inhibitory neurotransmitter in spinal interneurons

Glycine

42

Ion INFLUX increased by Glycine

Cl-

43

From which GABA is synthesized

Glutamate

44

Ion INFLUX increased by GABA-A

Cl-

45

Ion EFFLUX increased by GABA-B

K+

46

NT involved in SLOW pain transmission

Substance P

47

RMP contributors (3)

1) Nernst potential for Na (+61) and K (-94) diffusion
2) Na-K leak channels or K-leak channels (100x more permeable to potassium
3) Na-K ATPase pump (-4mV)

48

Characteristics of an AP

1) Stereotypical size and shape
2) Propagating in a nondecremental manner
3) All-or-none

49

Threshold for AP

-30mV

50

Portion of AP where MP is less than RMP

Undershoot

51

Activation gate

M gate

52

Inactivation gate

H gate

53

Na channel gates at rest

Closed M gate, opened H gate

54

Na channel gates at upstroke

Opened M gate, opened H gate

55

Na channel gates at repolarization

closed H gate

56

Gates that contribute to repolarization (2)

1) Closed Na inactivation gate
2) Opened K gates causing K efflux

57

Responsible for undershoot

Prolonged opening of K gates

58

Configuration of Na channel gates during undershoot

Closed M gate, closed H gate

59

Ionic basis of ARP

No action potential can occur until the Na-inactivation gates open

60

Ionic basis for RRP

Membrane potential is closer to K equilibrium potential and farther from threshold

61

Happens when cell is depolarized so slowly that threshold potential is passed with firing an AP since critical number of open Na channels os not attained

Accomodation

62

Effect of hyperkalemia on cardiac muscle

Depolarization

63

Effect of hypokalemia on cardiac muscle

Hyperpolarization

64

Synaptic inputs that hyperpolarize the post-synaptic cell

IPSP

65

Repeated stimulation --> Response greater than expected

Nerve facilitation

66

Increased NT release and increased sensitivity to NT

Long-term potentiation

67

Repeated stimulation --> decreased response

Synaptic fatigue

68

Fibers in order of myelination (greatest to none)

A > B > C

69

Fibers for proprioception

A alpha

70

Fibers for touch and pressure

A beta

71

Fibers that are motor to muscle spindles

A gamma

72

Fibers for touch, fast pain, and cold

A delta

73

Extrafusal nerve fibers

A alpha

74

Preganglionic autonomic fiber type

B fibers

75

Slow pain, temp, mechanoreception (smell)

C - dorsal root

76

Postganglionic SY

C - sympathetic

77

Sodium channel blocker of neurons

1) Tetradotoxin
2) Saxitoxin

78

Potassium channel blocker of neurons

Tetraethylammonium

79

Respiratory, swallowing, coughing, and vomiting centers

Medulla

80

Micturitiom, pneumotaxic, and apneustic centers

Pons

81

Relay center for almost all sensations except olfaction

Thalamus

82

Motor, personality, calculation, judgement

Frontal

83

Somatosensory cortex

Parietal

84

Hearing, vestibular processing, recognition of faces, Meyer's loop (optic pathway)

Temporal

85

Memory

Temporal

86

Plans and creates motor pattern for speech

Broca's area

87

Brodmann's areas of Broca's area

1) 44 (pars opercularis)
2) 45 (pars triangularis)

88

Location of Broca's area (lobe)

Frontal

89

Area for behavior, emotions, and motivation

Limbic association area

90

Broca's expressive aphasia is aka

Affluent aphasia

91

Receptive aphasia

Wernicke's aphasia

92

Brodmann's area of Wernicke's aphasia

22

93

Location of Wernicke's area in brain

Superior temporal gyurs in the dominant hemisphere

94

Conversion of short-term memory to long-term memory

Consolidation

95

Lesion in this part of the brain will cause anterograde amnesia

Hippocampus

96

Lesion in this part of the brain will cause retrograde amnesia

Thalamus

97

Produce oxytocin

Paraventricular nuclei

98

Produce vasopressin

Supraoptic nuceli

99

Satiety center

Ventromedial nuclei

100

Hunger center

Lateral nuclei

101

Sweating/ heat release

Anterior hypothalamus

102

Shivering/ heat conservation

Posterior hypothalamus

103

Reward center

Medial forebrain bundle

104

Punishment center

Central gray area

105

Social inhibition

Amygdala

106

Biologic clock

SCN

107

Regulates SY activity that controls secretion of melatonin from pineal gland

Light signals from retina

108

Order of sleep waves

BATS DB
1) beta
2) alpha
3) theta
4) sleep spindles and K complexes
5) delta
6) beta

109

Waves during St1 sleep

Alpha interspersed with theta

110

Waves during St2 sleep

Theta inerrupted by sleep spindles and K complexes

111

Waves during St3

Delta waves interrupted by sleep spindles

112

Waves during St4

Delta

113

% REM in NB

50%

114

BP that is autoregulated in brain

60-140 mmHg

115

Substance that autoregulates cerebral blood flow

CO2

116

Effect of CO2 on cerebral blood vessels

Vasodilation

117

Gray matter vs white matter: More metabolic

Gray

118

Organs whose blood flow is not affected much by ANS

1) Brain
2) Heart
3) Kidneys
4) Exercising skeletal muscle

119

The brain is ___% of body weight

2

120

Sources of energy of brain (2)

1) Glucose
2) Ketone bodies

121

Order of abundance of ketone bodies

B-hydroxybutyrate > acetoacetate > acetone

122

Amount of CSF in brain

150mL

123

Amount of CSF produced per day

500mL

124

Function of CSF

Cushioning

125

CSF is produced in which parts of the brain (2)

1) Choroid plexus (70%)
2) Brain parenchyma (30%)

126

CSF pathway

Lateral ventricles > foramen of monroe > third ventricle > cerebral aqueduct of sylvius > 4th ventricle > foramen of megendie and luschka > subarachnoid space > arachnoid granulations > dural venous sinus blood

127

Cardiac output of major organs from greatest to least

Liver > Kidneys > Skeletal muscle > brain > skin

128

Components of BBB

1) Endothelial cells
2) Astrocyte foot processes
3) Choroid plexus

129

BBB exists in all areas except

1) Some areas of hypothalamus
2) Pineal gland
3) Area postrema
4) Organum vasculosum of lamina terminalis (osmotic sensing)
5) Neurohypophysis (ADH release)

130

Location of cell body of preganglionic neuron in SY ANS

Thoracolumbar

131

Location of cell body of preganglionic neuron in PSY ANS

Craniosacral

132

Location of cell body of postganglionic neuron in SY ANS

Paravertebral or prevertebral ganglia

133

Location of cell body of postganglionic neuron in PSY ANS

Walls of effector organs

134

Second msgr of alpha1 adrenoreceptor

IP3

135

Second msgr of alpha2, beta1, and beta2 adrenoreceptor

cAMP

136

Mechanism of action of nicotinic cholinoreceptor

Opens Na and K channels for depolarization

137

Mechanism of action of muscarinic cholinoreceptor

IP3 and cAMP

138

ANS Receptor stimulatory to vascular smooth muscle

Alpha1

139

ANS Receptor inhibitory to vascular smooth muscle

Beta2

140

ANS Receptor stimulatory to the heart

Beta1

141

ANS Receptor inhibitory to smooth muscles of bronchioles

Beta2

142

ANS receptor stimulatory to smooth muscles of bronchioles

Muscarinic

143

ANS Receptor stimulatory to GI sphincter and bladder sphincter

Alpha1

144

ANS Receptor that is inhibitory to bladder wall (detrussor)

Beta2

145

ANS receptor that mediates mydriasis by radial muscle contraction

Alpha1

146

ANS receptor that mediates miosis by circular sphincter muscle contraction

Muscarinic

147

Kidney function mediated by SY nervous system

Renin secretion by JG cells

148

ANS Receptor for renin secretion

Beta1

149

Downstream action of IP3

Mobilizes Ca ions from mitochondria and ER > smooth muscle contraction and cell secretion

150

Downstream action of DAG

Activates PKC

151

Second messenger from which arachidonic acid is derived for synthesis of protaglandins and other local hormones

DAG

152

Lacrimal gland secretion receptor

Muscarinic

153

SY vs PSY: Mucoid salivation

SY

154

SY vs PSY: Watery salivation (parotid)

PSY

155

SY vs PSY: Uterine contraction

SY

156

SY vs PSY: Penile erection

PSY

157

SY vs PSY: Penile ejaculation

SY

158

Organs without PSY innervations

1) Ventricles
2) Gravid uterus
3) Blood vessels