Neurophysiology, Topnotch Flashcards
1
Q
Functions of astrocytes
A
1) Regulate ECF ion levels
2) Mechanical support
3) Forms BBB
2
Q
Creates myelin in CNS
A
Oligodendrocytes
3
Q
Creates myelin in PNS
A
Schwann cells
4
Q
Brain tumors from immature neurons (2)
A
1) Neuroblastoma
2) Retinoblastoma
5
Q
Where action potential in a neuron starts
A
Axon hillock
6
Q
Branches of axons
A
Neural fibrils
7
Q
Terminal portion of neural fibril that contains NT-containing vesicles
A
Axon buotons
8
Q
Part of a synapse where there is a high density of mitochondria
A
Presynaptic terminal of a cholinergic neuron
9
Q
Where K channels are highly concentrated
A
Paranodal axolemma and Schwann cell membrane
10
Q
Death of axon distal to site of injury
A
Wallerian degeneration
11
Q
CNS vs PNS: Where axonal regeneration occurs better
A
PNS
12
Q
Sites of ACh secretion (5)
A
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
Q
ACh synthesis
A
Acetyl CoA + choline catalyzed by choline acetyltransferase
14
Q
Main neurotransmitter in REM sleep
A
ACh
15
Q
ACh degradation
A
Acetate + choline catalyzed by acetylcholinesterase whereby choline is recycled
16
Q
ACh is deficient in what disease entity
A
1) Alzheimer’s disease
2) Huntington’s disease
17
Q
Dopamine is deficient in what disease entity
A
1) Parkinson’s disease
2) Depression
18
Q
Main sites of dopamine (2)
A
1) Substancia nigra pars compacta
2) VTA
19
Q
Enzymes that degrade dopamine
A
1) MAO in presynaptic nerve terminals
2) COMT in tissues
20
Q
What hormone is in excess in Schizophrenia
A
Dopamine
21
Q
Sites of NE and Epinephrine secretion (4)
A
1) Locus ceruleus in pons
2) Brainstem
3) Hypothalamus
4) Postganglionic SY except sweat glands
22
Q
Phenylalanine derivatives
A
1) Tyrosine
2) L-dopa
3) Dopamine
4) NE
5) Epinephrine
6) Thyroxine
7) Melanin
23
Q
Tryptophan derivatives
A
1) Melatonin
2) Serotonin
3) Niacin
24
Q
Tyrosine –> L-dopa enzyme
A
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
