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Question 1
What are the stages of pain physiology
transduction transmission perception modulation
Question 2
What is transduction
Painful stimuli will generate action potential at the nerve ending
Question 3
What is the process of transmission in pain physiology?
Transfer of the sensory signal from PNS to CNS
Question 4
What is the final stage of pain physiology called and what does it involve?
Modulation - decreasing or suppressing the painful sensation
Question 5
Activation of nociceptors
releases mediators like bradykinin, substance P, and histamine → activate ion-gated transient receptor potential channels on axon terminals → increases membrane permeability to sodium and calcium ions → action potential of the spinothalamic pathway
Question 6
What neurotransmitter do Aδ fibers release
glutamate
Question 7
What transmitters does C-fibers release
glutamate and substance P
Question 8
Pathway for pain signal from dorsal horn to somatosensory cortex?
Afferent fibers → second order neurons → thalamus → somatosensory cortex
Question 9
What is neural conduction?
neurons transmit signals through changes in ion conduction across the cell membrane
Question 10
What is membrane potential?
The difference of ion concentration across the cell membrane
Question 11
What is the resting membrane potential for neurons?
-70 mV
Question 12
resting membrane potential for K/Na in neurons
K+ is higher inside the cell Na+ is higher outside cell
Question 13
What is the Na, K ATPase pump responsible for?
Establishing the concentration difference of K+ and Na+ across the cell membrane.
Question 14
What is the Resting Stage in the context of an action potential?
• resting membrane potential before the action potential begins • freely permeable to potassium ions • membrane is polarized at -70 mV
Question 15
What happens during the Depolarization Stage of an action potential?
• sodium channels open • influx of sodium ions • increases the membrane potential to the positive direction
Question 16
What is the Repolarization Stage?
• threshold of +40 mV • sodium channels close • potassium channels are activity open • Rapid outflux of potassium ions
Question 17
What is the Refractory Period?
• depolarization till resting membrane potential • ion channels will not respond to any new stimuli
Question 18
What factors influence conduction velocity in nerve fibers?
Fiber diameter and myelination.
Question 19
Fiber diameter and velocity
larger diameter = lower resistance = faster
Question 20
Myelination and velocity
myelin = insulation = faster
Question 21
Process where action potentials move via jumps from node-to-node in myelinated axons?
Saltatory conduction
Question 22
What are the voltage-gated Na+ channels only expressed at in myelinated axons?
Nodes of Ranvier
Question 23
What are the advantages of saltatory conduction in myelinated axons?
• Saves energy by decreasing the use of sodium/potassium pump • increases speed for faster neural communication
Question 24
What is the effect of an excitatory postsynaptic potential (EPSP)?
Membrane depolarization of the postsynaptic neurons opening the sodium channels
Question 25
What is the effect of an inhibitory postsynaptic potential (IPSP)?
Membrane
hyperpolarization
inhibiting an action potential by activating chloride channels
Question 26
What is synaptic transmission?
Axon terminal of 1 neuron propagates signal to dendrites of another neuron
Question 27
What is an electrical synapse and how does it function?
transfers action potentials across gap junctions allowing free movement of ions from one cell to the next extremely rapid neural communication.
Question 28
What are the three main divisions of the peripheral nervous system?
Somatic nervous system, Autonomic nervous system
Question 29
What are the main branches of the Autonomic nervous system?
Sympathetic and Parasympathetic
Question 30
What are the two main subdivisions of the PNS?
Afferent (sensory) nerves and Efferent (motor) nerves
Question 31
T/F: Afferent nerves are pseudounipolar
True
Question 32
TF: Efferent nerves are multipolar
True
Question 33
What neurotransmitter is released at the neuromuscular junction in somatic nervous system?
Acetylcholine
Question 34
What is the function of the Somatic nervous system?
Responsible for voluntary control
Question 35
What is the main purpose of the Autonomic Nervous System?
homeostasis and integrate the stress response.
Question 36
What functions does the Autonomic Nervous System control?
controls involuntary functions • regulates blood pressure • GI responses to food • bladder contraction of the urinary bladder
Question 37
What is the function of the Enteric nervous system?
function independently of the remainder of the nervous system • regulating digestive processes
Question 38
What are the functions of the Sympathetic and Parasympathetic nervous systems?
Sympathetic: Fight or Flight reactions and exercise Parasympathetic: Rest and Digest reactions
Question 39
Function of hypothalamus in central control of the autonomic nervous system?
• integrates info and sends output down spinal cord via hypothalamospinal tract • engages preganglionic fibers of sympathetic/parasympathetic nervous systems
Question 40
Medulla role in central control of ANS
vasomotor and vasodilator centers respiratory center
Question 41
Role of the pons in central control of ANS
respiratory center
Question 42
Where is the parasympathetic nervous system controlled from
hypothalamus
Question 43
What do preganglionic efferent fibers release?
acetylcholine
to activate nicotinic receptors of postganglionic fibers
Question 44
What do Post-ganglionic fibers release?
_norepinephrine_
acetylcholine
to activate muscarinic receptors of the effector organs
epinephrine
norepinephrine
Question 45
What controls the sympathetic nervous system
Hypothalamus control
Question 46
What do preganglionic of SNS fibers release?
releasing acetylcholine
Question 47
What do postganglionic fibers of SNS release?
noradrenaline
Question 48
Describe length of fibers in SNS vs PSNS
SNS
• pre: short • post: long
PSNS
• pre: long • post: short
Question 49
What are the three main classes of neurotransmitters?
Excitatory, Inhibitory, Modulatory
Question 50
List the excitatory neurotransmitters.
Glutamate Acetylcholine Norepinephrine
Question 51
What are the inhibitory neurotransmitters?
GABA Glycine
Question 52
What are the modulatory neurotransmitters?
Dopamine Serotonin
Question 53
What are the types of small molecules, rapid-acting neurotransmitters?
Amino acids monoamines gaseous purines acetylcholine
Question 54
What is the role of acetylcholine in the nervous system?
neurotransmitter of sympathetic preganglionic neurons + PSNS
Question 55
How is acetylcholine synthesized and degraded?
Synthesized: by choline acetyltransferase from Acetyl-CoA and Choline Degraded: by acetylcholinesterase
Question 56
Which types of fibers are cholinergic?
Nicotinic Muscarinic
Question 57
Where are nicotinic receptors located
N1 + N2 • Neuromuscular junction in skeletal muscles • CNS • adrenal medulla • autonomic ganglia
Question 58
What are Muscarinic receptors subdivided into?
M1, M2, M3, M4, and M5
Question 59
Where are Muscarinic receptors located?
On the effector organs
Question 60
Where are M1 receptors located
brain
Question 61
Where are M2 receptors located
heart
Question 62
Where are M3 receptors located
bladder, exocrine glands, and smooth muscle
Question 63
What are catecholamines?
hormones and neurotransmitters produced by the adrenal glands and nervous system
Question 64
Which two catecholamines stimulate adrenergic receptors of the SNS?
Adrenaline and noradrenaline
Question 65
What is the common amino acid from which catecholamines are synthesized?
Tyrosine
Question 66
catecholamine production pathway
tyrosine → DOPA → dopamine → norepi → epi
Question 67
What is the primary function of noradrenaline (norepinephrine) in the sympathetic nervous system (SNS)?
mediates SNS by interacting w/ adrenergic receptors activates α1, α 2, β1 receptors
Question 68
Which receptors does noradrenaline activate?
activates α1, α 2, β1 receptors
Question 69
How is noradrenaline inactivated in the body?
via oxidation via monoamine oxidase (MAO) or methylation with catechol-0-methyltransferase (COMT)
Question 70
Which receptors does adrenaline (epi) bind to?
bind/activate all five alpha and beta receptors.
Question 71
α1 receptor location and function
L: Blood vessels, eye, bladder F: Vasoconstriction, mydriasis, closure of bladder sphincter
Question 72
α2 receptor location and function
L: Synaptic nerve ending F: prevents norepi and Ach release
Question 73
β1 receptor location and function
L: heart F: increase HR and contraction force
Question 74
β2 receptor location and function
L: Arteries, bronchi, uterus F: VD, bronchodilation, ↑ blood glucose
Question 75
β3 location and function
L: Adipose tissue F: lipolysis
Question 76
How is dopamine synthesized?
directly synthesized from L-Dopa
Question 77
What is serotonin (5-HT) and what functions does it perform in the body?
monoamine neurotransmitter sleep, eating, arousal, dreaming, mood regulation, and temperature/pain transmission
Question 78
How is serotonin synthesized in serotonergic neurons?
synthesized from the amino acid tryptophan
Question 79
Where is serotonin found in high concentrations in the body?
in enterochromaffin cells throughout the GI tract storage granules in platelets and CNS
Question 80
GABA function
inhibitory
neurotransmitter reduces the excitability of neurons by hyperpolarization
Question 81
How is GABA synthesized
from glutamate via glutamate decarboxylase
Question 82
Glycine function
inhibitory neurotransmitter in the CNS
Question 83
What is glycine synthesized from?
from serine by serine hydroxy-methyltransferase
Question 84
What is the role of glutamate in the central nervous system (CNS)?
excitatory neurotransmitter in the CNS uses N-methyl-D-aspartate (NMDA) receptors
Question 85
What mnemonic can be used to remember the vascular causes of seizures?
VITAMINS
➢ Vascular (stroke, intracranial hemorrhage) ➢ Infection ➢ Trauma ➢ Autoimmune ➢ Metabolic ➢ Idiopathic ➢ Neoplasm ➢ pSychiatric, genetic factor
Question 86
Epilepsy in relation to neurotransmitter dysfunction
Too much glutamate - excitation Too little GABA - inhibition
Question 87
What does a neurological exam include?
Behavior, movements, and mental function tests.
Question 88
What do blood tests detect in the context of seizures?
Infections, genetic or metabolic conditions.
Question 89
What do imaging and electroencephalogram (EEG) do?
detects structural abnormalities EEG detects electrical activity in the brain
Question 90
Symptoms/Phases of a seizure
Prodromal
• nonspecific emotional changes • hours-days before
Aura
• changes in emotions, hearing, smell, taste or vision • Minutes before seizure
Ictal
• seizure type specific
Post-ictal
• fatigue, confusion, soreness, amnesia, thirst
Question 91
What is the difference between focal and generalized seizures?
Focal: originate from a specific area of the brain Generalized: affect the entire brain
Question 92
Ttypes of focal seizures
Simple partial Focal impaired awareness seizure
Question 93
Types of generalized seizures?
Tonic seizure Clonic seizure Tonic-clonic seizure Absence seizure
Question 94
What is the definition of a simple partial seizure?
preserved consciousness
preceded by an aura, followed by motor signs
Question 95
What is a focal impaired awareness seizure
accompanied by a
loss of consciousness
preceded by an aura between 30 second-2 minutes
Question 96
What is a tonic seizure?
Stiff/flexed
• continuous muscle contraction • rigid and flexed • accompanied by patient falling backward
Question 97
What is an atonic seizure
muscle relaxtion
patient falls forward
Question 98
What is a clonic seizure
convulsions
• rhythmic, violent jerking • without initial tonic phase
Question 99
What is a myoclonic seizure
short muscle twitches
• loss of consciousness
Question 100
What is a tonic-clonic seizure
both tonic an clonic phase
• initial stiffening • followed by jerking • most common gen seizure
Question 101
What is an absence seizure
loss and gain of consciousness
• start abruptly • brief lapse in consciousness • lasts 10 seconds
Question 102
What is status epilepticus
is seizure lasts more that 5 minutes usually tonic clonic
Question 103
What are anticonvulsants and how do they work?
reduce seizures by enhancing GABA activity or modulating glutamate activity
Question 104
What is the surgical approach for managing drug-resistant focal epilepsy?
resection of the epileptogenic cortex
Question 105
How does the ketogenic diet influence neuronal excitability?
state of ketosis → enhanced GABA levels + reduced neuronal excitability
Question 106
What is Parkinson's disease?
progressive neurodegenerative disease
Question 107
Pathophysiology of PD
• degeneration of dopaminergic neurons in substantia nigra pars compacta • depletion of dopamine • Clinical symptoms = >60% of Dop neurons depleted • Lewy bodies present
Question 108
Clinical manifestations of PD
1. tremors 2. rigidity 4. bradykinesia 4. postural instability