Neuro Physiology Flashcards
1
Q
Glial cells: Which is more numerous: glial cells or neurons?
A
Glial cells (10:1 ratio)
2
Q
Glial cells: produces CSF
A
Ependymal cells
3
Q
Glial cells: macrophage of the brain
A
Microglia
4
Q
Glial cells: regulates ECF ion levels, gives mechanical support; forms BBB
A
Astrocyte (nurse cells)
5
Q
Glial cells: creates myelin in the CNS
A
Oligodendrocytes
6
Q
Glial cells: creates myelin in the PNS
A
Schwann cells
7
Q
Glial cells: brain tumors from non-mature neurons
A
Retinoblastoma, Neuroblastoma
8
Q
Parts of a neuron: receiving portion for neurotransmitters of the neuron
A
Dendrites
9
Q
Parts of a neuron: where action potential in a neuron actually starts
A
Axon hillock
10
Q
Parts of a neuron: function of myelin sheath
A
Insulator
11
Q
Parts of a neuron: Unmyelinated portion of the acon
A
Nodes of Ranvier
12
Q
Parts of a neuron: branches of the axons
A
Neural fibril
13
Q
Parts of a neuron: terminal portion of a neural fibril that contains NT-containing vesicles
A
Axon terminal/boutons/end-feet
14
Q
Parts of a neuron: space between 2 neurons
A
Synapse
15
Q
Differentiate anterograde and retrograde axonal transport
A
Anterograde: soma to axon terminal; Retrograde: axon terminal to soma
16
Q
What do you call the death of the axon distal to the site of injury after an axon is transected?
A
Anterograde/Orthograde/Wallerian degeneration
17
Q
What do you call the changes to the soma after an axon is transected?
A
Axonal reaction/Chromatolysis
18
Q
Axonal regeneration occurs better in the CNS or PNS?
A
PNS
19
Q
Where in the basal ganglia is acetylcholine secreted?
A
Nucleus Basalis of Meynert
20
Q
What enzyme is used in the synthesis of acetylcholine?
A
Choline acetyltransferase
21
Q
What enzyme is used in the degradation of acetylcholine?
A
Acetylcholinesterase
22
Q
What enzyme triggers sleep and is deficient is Alzheimer’s disease?
A
Acetylcholine
23
Q
Where is Dopamine mainly found?
A
Substantia nigra pars compacta & ventral tegmental area
24
Q
What enzyme degrades Dopamine?
A
MAO in presynaptic nerve terminals, COMT in tissues including liver
25
What condition is caused by Dopamine deficiency?
Parkinson's disease
26
What condition is caused by Dopamine excess?
Schizophrenia
27
Norepinephrine is secreted by:
locus ceruleus in the pons, and postganglionic neurons of sympathetic nervous system
28
Phenylalanine Derivatives
Phenylalanine, Tyrosine, L-Dopa, Dopamine, Norepinephrine, Epinephrine, Thyroxine, Melanin
29
Tryptophan Derivatives
Tryptophan, MelaTOnin, Serotonin, Niacin
30
Serotonin is secreted mainly by:
Median raphe of the brain stem
31
Low levels of this substance causes clinical depression
Serotonin (also inhibits pain pathways in the spinal cord)
32
Substance responsible for long term behavior and memory
Nitric oxide (from Arginine)
33
What is the property of NO that differs from other neurotransmitters?
NO is not preformed and stored in vesicles. It is synthesized almost instantly as needed
34
Histamine is mainly located within the:
tuberomammilary nuecleus of the hypothalamus
35
What is the function of histamine?
Involved in control of arousal, sleep and circadian rhythm
36
Inhibitory neurotransmitter usually found in spinal interneurons; increases chloride influx
Glycine
37
Number one inhibitory neurotransmitter in the brain; comes from Glutamate; increases chloride influx or potassium efflux
GABA
38
Number one excitatory neurotransmitter in the brain; involved in fast pain
Glutamate
39
Inhibit neurons in the brain involved in the perception of pain
Opioid peptides (enkephalins, endorphins, dynorphins)
40
Involved in slow pain transmission; in specific areas of the brain, primary sensory neurons, GI plexus neurons
Substance P
41
Basis for the resting membrance potential and action potential
Ion channels
42
potential difference that exist across the membrane; exhibited by almost all cells; refers to INTRAcellular charge
Resting Membrane Potential
43
3 things that contribute to the resting membrane potential
1. Nernst potential for Na and K diffusion
2. Na-K leak channels/ K leak channels
3. Na-K-ATPase pump
44
What types of cells exhibit action potential?
Only excitable cells (neurons, muscles, cells)
45
Action Potential: each normal AP for a given cell type looks identical, depolarizes to the same potential and repolarizes to the same RMP
Stereotypical size and shape
46
Action Potential: AP at one cell causes depolarization of adjacent cells in a nondecremental manner
Propagating
47
Action Potential: If threshold is reached, a full-sized AP will be produced, otherwise, none at all
All-or-none
48
RMP & AP: make the membrane potential less negative
Depolarization
49
RMP & AP: make the membrane potential more negative
Hyperpolarization
50
RMP & AP: positive charges flowing into the cell
Inward current
51
RMP & AP: positive charges flowing out of the cell
Outward current
52
RMP & AP: MP in which AP is inevitable
Threshold
53
RMP & AP: portion of the AP where MP is positive
Overshoot
54
RMP & AP: portion of the AP where MP is less than RMP
Undershoot (hyperpolarizing afterpotential)
55
What causes depolarization?
Opening of the Na-activation gates ) causes sodium influx)
56
What causes repolarization?
Closure of Na-inactivation gates (stops Na influx) and opening of potassium gate (potassium efflux)
57
What causes the undershoot?
Na activation and inactivation gates are both closed, while potassium gate is still open, making the MP more negative and farther from the RMP.
58
Examples of sodium channel blockers of neurons
Tetradotoxin (from pufferfish), Saxitoxin
59
Example of potassium channel blocker of neurons
Tetraethylammonium (from pufferfish)
60
True or False: Na and K channels are responsibile for all types of action potential.
False. Ca2+ channels in muscles.
61
What stimulates nerve depolarization in the first place?
Mechanical disturbance, chemicals, electricity
62
Time periods in an action potential during which a new stimulus cannot be readily elicited
Refractory periods
63
Time period in an action potential during which an action potential cannot be elicited, no matter how large the stimulus
Absolute refractory period
64
What is the ionic basis of absolute refractory period?
Inactivation gates of the Na channel are close when the MP is depolarized and remian closed until repolarization occurs; No AP can occur until the Na-inactivation gates open
65
Begins at the end of the absolute refractory period and continues until the MP returns to the resting level; AP can be elicited only if a larger than usual inward current is provided.
Relative refractory period
66
What is the ionic basis of relative refractory period?
During RRP, K conductance is elevated (prolonged opening of K channels); MP is closer to the K equilibrium and farther from threshold
67
This happens when a cell is depolarized so slowly such that the threshold potential is passed without firing an action potential; critical number of open Na channels is not attained due to closure of inactivation gates; opening of K channels oppose depolarization
Accomodation
68
In an excitable cell such as the heart muscle, what is the effect of hyperkalemia and hypokalemia respectively?
Hyperkalemia: depolarizes the heart (slows leakage of K+ to outside of the heart, making the cell more positive, RMP more positive, closer to threshold); cause VFib
Hypokalemia: hyperpolarizes the heart
69
Synaptic inputs that depolarize the post synaptic cell
Excitatory post-synaptic potential
70
Synaptic inputs that hyperpolarize the post synaptic cell
Inhibitory post-synaptic potential
71
Two or more presynaptic inputs arrive at postsynaptic cell simultaneously
Spatial summation
72
Two or more presynaptic inputs arrive at postsynaptic cell in rapid succession
Temporal summation
73
Repeated stimulation causes response of postsynaptic cell to be greater than expected
Nerve facilitation
74
Increased release of NT and increased sensitivity to the NT
Long term potentiation
75
Repeated stimulation causes decreased response of postsynaptic cell
Synaptic fatigue
76
In general type A nerve fiber compared to type c fibers are:
Thicker, more myelinated, faster
77
Fiber type: for proprioception, somatic motor
Type A alpha
78
Fiber type: for touch, pressure
Type A beta
79
Fiber type: for motor to muscle spindle
Type A gamma
80
Fiber type: for pain, cold, touch
Type A delta
81
Fiber type: preganglionic autonomic fiber
Type B
82
Fiber type: for pain, temperature, smell
Type C, dorsal root
83
Fiber type: postganglionic sympathetic fiber
Type C, sympathetic
84
Brain: vasomotor center, respiratory center (DRG,VRG), swallowing, coughing & vomiting center
Medulla
85
Brain: micturition center, pneumotaxic, apneustic centers
Pons
86
Brain: relay center for almost all sensations
Thalamus
87
Brain: contributes to balance
Cerebellum
88
Brain: connects the two brain hemispheres
Corpus callosum; anterior commisure
89
Brain: motor, personality, calculation
Frontal lobe
90
Brain: somatosensory cortex
Parietal lobe
91
Brain: vision
Occipital lobe
92
Brain: hearing, vestibular processing, recognition of faces, optic pathway (Meyer's loop)
Temporal lobe
93
Three categories of the cerebral cortex:
Primary area (initiation), Secondary area (interpretation), Association area (integration)
94
Association area: for elaboration of thoughts, plan complex motor movements
Prefrontal association area
95
Association area: plans and creates motor pattern for speech
Broca's area
96
Association area: behavior, emotions, motivation
Limbic association area
97
Process of converting short term to long term memory
Consolidation
98
An important pathway from the reward and punishment centers of the brain; lesions in this area will cause anterograde amnesia (loss of short term memory)
Hippocampus
99
Role in memory search and reading out the memories; lesions in this are will cause retrograde amnesia (loss of pre-existing memories)
Thalamus
100
Limbic System: produces mainly oxytocin
Paraventricular nuclei
101
Limbic System: produces mainly vasopressin
Supraoptic nuclei
102
Limbic System: satiety center
Ventromedial nuclei
103
Limbic System: hunger center
Lateral nuclei
104
Limbic System: sweating (heat release)
Anterior hypothalamus
105
Limbic System: shivering (heat conversation)
Posterior hypothalamus
106
Limbic System: reward center
Medial forebrain bundle
107
Limbic System: punishment center
Central gray area around aqueduct of sylvius
108
Limbic System: social inhibition
Amygdala
109
Which is more powerful in creating new memories, punishment & fear, or pleasure & reward?
Punishment and fear
110
Regulate activity of many physiological processes including HR, BP, body core temperature, and blood levels of hormones
Biological clock
111
Master clock of all biological clocks in the human body; destruction causes loss of circadian functions
Suprachiasmatic nucleus
112
Regulates circadian rhythms; secreted hormone melatonin
Pineal gland
113
Melatonin is ____ during darkness, ____ by daylight, controlled by ______ nerve activity
Increased, inhibited, sympathetic
114
EEG waves: awake, eyes closed (8-13 Hz)
Alpha waves
115
EEG waves: awake, eyes open (13-30 Hz)
Beta waves
116
EEG waves: brain disorders and degenerative brain states (4-7 Hz)
Theta waves
117
EEG waves: deep sleep, organic brain disease, infants (0.5-4 Hz)
Delta waves
118
Sleep is an active inhibitory process possibly caused by:
Secretion of Muramyl peptide
119
EEG waves seen in Stage 1 slow-wave sleep
Alpha waves interspersed with Theta waves
120
REM sleep is associated with active dreaming. It occurs every ___ of slow wave sleep. EEG waves seen are:
90 minutes, Beta waves
121
EEG waves seen in Stage 2 slow-wave sleep
Theta waves interrupted by sleep spindles (12-14 Hz) and K complexes
122
EEG waves seen in Stage 3 slow-wave sleep
Delta waves interrupted by sleep spindles
123
EEG waves seen in Stage 4 slow-wave sleep
Delta waves alone
124
Who among the following dream the most: newborns, young adults, elderly?
Newborns (50% REM sleep)
125
Cerebral blood flow is highly autoregulated at BP between:
60 - 140 mmHg
126
Which is more metabolic, gray matter or white matter?
Gray matter
127
Brain is the most metabolic organ of the body. It is 2% of body mass but ___ of total metabolism
15%
128
Primary source of energy of the brain
Glucose (but also uses ketone bodies)
129
Total amount of CSF in the brain
150 mL (in the brain ventricles, subarachnoid space, subarachnoid cistern)
130
Amount of CSF produces per day:
500 mL (70% choroid plexus, 30% brain)
131
Main function of the CSF:
cushioning
132
The Na-K-ATPase pump is found on which side of the choroid plexus?
Luminal side
133
Which has more Na, CSF or blood?; Which has more protein, CSF or blood?
CSF (148 vs 136-145); Blood (6800 vs 15-45)
134
3 components of the blood brain barrier:
Endothelial cells of cerebral capillaries, Astrocyte foot processes, Choroid plexus epithelium
135
Areas without a blood brain barrier/ circumventricular organs:
some areas of the hypothalamus, pineal gland, area postrema (floor of 4th ventricle)
136
Mediates release of epinephrine from the adrenal medulla
Cholinergic nicotinic receptors
137
The zombie virus uses what kind of axonal transport
Retrograde axonal transport
