Neurophysiology ( Bajads) Flashcards
plays an important role in controlling and regulating every aspect of bodily actions
NERVOUS SYSTEM
consists of the brain and spinal cord
A. CENTRAL NERVOUS SYSTEM
B. PERIPHERAL NERVOUS SYSTEM
A
main control center
A. CENTRAL NERVOUS SYSTEM
B. PERIPHERAL NERVOUS SYSTEM
A
divided into sensoryand motor division
A. CENTRAL NERVOUS SYSTEM
B. PERIPHERAL NERVOUS SYSTEM
B
picks up sensory stimuli
A. Sensory
B. Motor
A
sends directions from brain to muscles and glands
A. Sensory
B. Motor
B
afferent
A. Sensory
B. Motor
A
efferent
A. Sensory
B. Motor
B
voluntary
A. Somatic Nervous System
B. Autonomic Nervous System
A
rules skeletal muscle movement
A. Somatic Nervous System
B. Autonomic Nervous System
A
involuntary
A. Somatic Nervous System
B. Autonomic Nervous System
B
keeps heart beating, lungs breathing,
and stomach churning
A. Somatic Nervous System
B. Autonomic Nervous System
B
AUTONOMIC NERVOUS SYSTEM
Is divided into?
Sympathetic Division
Parasympathetic Division
mobilizes the heart contraction
A. Sympathetic Division
B. Parasympathetic Division
A
relaxes
A. Sympathetic Division
B. Parasympathetic Division
B
densely packed nerve cells or neurons (the structural unit)
NEURON
transmit messages
NEURON
T/ F
NEURON vary in size & length
T
contains nutrients
A. Cell Body
B. Dendrite
C. Axon
A
powerhouse
A. Cell Body
B. Dendrite
C. Axon
A
receives messages
A. Cell Body
B. Dendrite
C. Axon
B
good listeners
A. Cell Body
B. Dendrite
C. Axon
B
distributes or spreads the message
A. Cell Body
B. Dendrite
C. Axon
C
in cell body, has several processes
A. Multipolar
B. Bipolar
C. Unipolar
A
found in the sensory neurons
A. Multipolar
B. Bipolar
C. Unipolar
A
rare
A. Multipolar
B. Bipolar
C. Unipolar
B
found in the retina of the eye
A. Multipolar
B. Bipolar
C. Unipolar
B
cell body is at the center
A. Multipolar
B. Bipolar
C. Unipolar
B
transmit impulses from sensory receptors toward the CNS
A. Sensory Neurons
B. Motor Neurons
C. Interneurons
A
mostly unipolar
A. Sensory Neurons
B. Motor Neurons
C. Interneurons
A
impulses move from the CNS to the rest of the body
A. Sensory Neurons
B. Motor Neurons
C. Interneurons
B
mostly multipolar
A. Sensory Neurons
B. Motor Neurons
C. Interneurons
D. A &B
E. B&C
E
association neurons
A. Sensory Neurons
B. Motor Neurons
C. Interneurons
C
impulse move between sensory and motor neurons
A. Sensory Neurons
B. Motor Neurons
C. Interneurons
C
impulse move between sensory and motor neurons
A. Sensory Neurons
B. Motor Neurons
C. Interneurons
C
these messages, in the form of electrical action potentials, are called ____
impulses
Self-propagated passage of an electrical current along nerve fibers
NERVE CONDUCTION
negative electric potential (-70 mV)
A. RESTING STATE
B. DEPOLARIZATION
C. REPOLARIZATION
A
negative (anions) on the inside of the cell membrane and
positive (cations) are gathered outside
A. RESTING STATE
B. DEPOLARIZATION
C. REPOLARIZATION
A
slightly permeable to sodium ions
A. RESTING STATE
B. DEPOLARIZATION
C. REPOLARIZATION
A
freely permeable to potassium ions
A. RESTING STATE
B. DEPOLARIZATION
C. REPOLARIZATION
A
freely permeable to chloride ions
A. RESTING STATE
B. DEPOLARIZATION
C. REPOLARIZATION
A
→ excitation of a nerve segment leads to an increase of permeability of the cell membrane to sodium ions
→ rapid influx of sodium ions
A. RESTING STATE
B. DEPOLARIZATION
C. REPOLARIZATION
B
→ resting level to its firing threshold of approximately -50 to -60
mV
A. RESTING STATE
B. DEPOLARIZATION
C. REPOLARIZATION
B
→ the firing threshold is actually the magnitude of the decrease in
negative transmembrane potential that is necessary to initiate
action potential (impulse)
→ the process takes approximately 0.3 msecs
A. RESTING STATE
B. DEPOLARIZATION
C. REPOLARIZATION
B
the permeability of the nerve membrane again decreases, while the high permeability to potassium is restored
A. RESTING STATE
B. DEPOLARIZATION
C. REPOLARIZATION
C
an expenditure of energy is necessary to move sodium ions out of the nerve cell against their concentration gradient; this energy comes from the oxidative metabolism of Adenosine Triphosphate (ATP)
A. RESTING STATE
B. DEPOLARIZATION
C. REPOLARIZATION
C
repolarization takes 0.7 msec
A. RESTING STATE
B. DEPOLARIZATION
C. REPOLARIZATION
C
immediately after a stimulus has initiated an action potential, a nerve is unable, for a time, to respond to another stimulus regardless of its strength
A. ABSOLUTE REFRACTORY PERIOD
B. RELATIVE REFRACTORY PERIOD
A
it lasts for about the duration of the main part of the action potential
A. ABSOLUTE REFRACTORY PERIOD
B. RELATIVE REFRACTORY PERIOD
A
period in which a new impulse can be initiated but only by a
stronger than normal stimulus
A. ABSOLUTE REFRACTORY PERIOD
B. RELATIVE REFRACTORY PERIOD
B
it continues to decrease until the normal level of excitability
returns, at which point the nerve is said to be repolarized
A. ABSOLUTE REFRACTORY PERIOD
B. RELATIVE REFRACTORY PERIOD
B
T/F
the spread of impulse differs depending on whether or not a nerve is myelinated
T
→ impulse conduction in myelinated nerves occurs by means of current leaps from node to node
→ this form of impulse conduction proves to be much faster and more energy efficient than that employed in unmyelinated nerves
→ nodes of Ranvier
SALTATORY CONDUCTION
an unpleasant emotional experience usually initiated by a noxious stimulus and transmitted over a specialized neural network to the central nervous system where it is interpreted as such
PAIN
the first aspect in the nature of pain
A. PAIN PERCEPTION
B. PAIN REACTION
A
the physioanatomical process whereby an impulse is generated, following application of an adequate stimulus and is transmitted to the central nervous system
A. PAIN PERCEPTION
B. PAIN REACTION
A
a psychophysiological process that represents the individuals overt manifestation of the unpleasant perceptual process that just occurred
A. PAIN PERCEPTION
B. PAIN REACTION
B
FACTORS THAT INFLUENCE PAIN REACTION THRESHOLD
emotional states
→ fatigue
→ age
→ racial and nationality characteristics
→ sex
→ fear and apprehension
Removing the cause
A. pain perception
B. pain reaction
C. Both
A
Blocking the pathway of painful impulses
A. pain perception
B. pain reaction
C. Both
A
Raising the pain threshold
A. pain perception
B. pain reaction
C. Both
C
Preventing pain reaction by cortical depression
A. pain perception
B. pain reaction
C. Both
B
Using psychosomatic needs
A. pain perception
B. pain reaction
C. Both
B
may be defined as that unpleasant sensation that has no organic basis
A. PSYCHOGENIC PAIN
B. REFERRED PAIN
A
→ it is any pain that originated wholly within the mind and is fixed on some portion of the anatomy
→ presents a difficult and sometimes embarrassing situation for the dentist
A. PSYCHOGENIC PAIN
B. REFERRED PAIN
A
pain experienced at a site some distance from the site of injury
A. PSYCHOGENIC PAIN
B. REFERRED PAIN
B
loss of sensation in a circumscribed area of the body caused by depression of excitation in nerve endings or inhibition of the conduction process in peripheral nerves
LOCAL ANESTHESIA
WHERE DO LOCAL ANESTHETICS WORK?
→ the ______ is the site at which local anesthetics exert their pharmacological action
nerve membrane
highly lipid-soluble anesthetics, such as benzoxaone, insert themselves into the lipid bilayer of the cell membrane, expanding and narrowing the sodium channels preventing depolarization
A. MEMBRANE EXPANSION THEORY
B. SPECIFIC RECEPTOR THEORY
A
→ the most favored today, proposes that local anesthetics act by binding to specific receptors on the sodium channel
→ the action of the drug is direct
A. MEMBRANE EXPANSION THEORY
B. SPECIFIC RECEPTOR THEORY
B
Once the local anesthetics has gained access to the receptors,
permeability to sodium ions is decreased or eliminated and nerve conduction is interrupted
A. MEMBRANE EXPANSION THEORY
B. SPECIFIC RECEPTOR THEORY
B
HOW LOCAL ANESTHETICS WORK
the primary action of local anesthetics in producing a conduction block is to ____ the permeability of ion channels to sodium ions
decrease
Arrange the ff.
SEQUENCE OF THE PROPOSED MECHANISM OF ACTION OF LOCAL ANESTHETICS
displacement of calcium ions from the sodium channel receptor sites
↓
binding of the local anesthetic molecule to the receptor site
↓
blockade of the sodium channel
↓
decrease in sodium conductance
1,2,3,4
is the greatest barrier to penetration of local anesthetics
perineurium
