OS 202 B Samplex 2011 Flashcards
(107 cards)
Which of the following sensation is generated by
impulses initiated in naked nerve endings?
a. Pain
b. Itch
c. Tickle
d. All of the above
A
When the vibratory sense is tested, which of the
following receptors are activated the most?
a. Paccinian corpuscle
b. Rufini endings
c. Meissner corpuscle
d. Meissner endings
A
Which of the following receptors do not contain
cation channels that are activated by mechanical
distortion?
a. Paccinian corpuscle
b. Hair cells in cochlea
c. Hair cells in semilunar canal
d. None of the above
D
Which of the following is true of generator
potential?
a. Generated in the 1st node of Ranvier
b. Result of summation of EPSP and IPSP
c. Propagated potential
d. Its amplitude is proportionate to the intensity
of stimulus
D
Which statement describes/illustrates the
Doctrine of Specific Nerve Energies?
a. Specific sensory pathways are discrete from the sense organ to the cortex
b. Excitation of a particular receptor by a stimulus always elicits the same sensation
c. A deaf person because of a middle ear disease can be made to “hear” tones by stimulating the auditory nerve
d. All of the above
D
The primary function of lateral inhibition in central
pathways is to
a. Define the central modality
b. Enhance contrast
c. Determine the duration sensation
d. Modulate the stimulus intensity
B
Which component of the sensory action potential
encodes the intensity of the sensation?
a. amplitude of the Action Potential
b. frequency of the action potential
c. both of the above
d. neither of the above
B
The part of the nervous system that is
responsible for the affect of any sensation is the
a. brainstem reticular formation
b. thalamus
c. amygdala
d. association area
C
Which sensory pathway bypasses the thalamus
and proceeds straight to the cortex?
a. Gustatory
b. Olfactory
c. Visual
d. auditory
B
A lesion in the primary sensory parietal cortex
will diminish to a larger extent which sensory
modality?
a. touch
b. stereognosis
c. pain
d. cold sensation
B
Which sensory modality is tested when a patient is asked to identify an object put in his hand with his eyes closed?
a. touch
b. stereognosis
c. graphesthesia
d. tactile localization
B
Which of the following is not a component of the
sensory unit
a. a dorsal horn neuron
b. a sensory axon
c. all peripheral branches of the axon
d. receptors within the sensory field
A
Which statement is true of rapidly adapting
receptors
a. they alert the nervous system to any change in the environment
b. they discharge during application and withdrawal of the stimulus
c. they are best suitable for spatio-temporal discrimination
d. AOTA
D
Which of the ff conditions would result in a decrease in muscle tone or hypotonia?
a. increase in the afferent input from the muscle spindles
b. destruction of the alpha motor neuron
c. inceased gamma motor neuron drive
d. any of the above condition
BC
When one steps on a pointed object, the following motor neuron pools in the spinal cord are activated
a. ipsilateral flexors, ipsilateral extensors and
contralateral extensors
b. ipsilateral flexors, contralateral extensors and
contralateral flexors
c. contralateral extensors, ipsilateral flexors
d. contralateral extensors, ipsilateral extensors
C
In the withdrawal reflex, the following sensory receptors are activated
a. bare nerve endings
b. muscle spindles
c. proprioceptors
d. AOTA
DC
While dissecting a specimen, a student accidentally stabbed his hand. The sudden acute pain that the student experienced is carried by which type of nerve fiber?
a. A-alpha
b. A-beta
c. A-delta
d. C fibers
C
The following statements are true of pain receptors EXCEPT
a. they are polymodal and respond to any noxious stimulus
b. they are widely distributed throughout the body
c. they easily adapt to continuous noxious stimulation
d. they are associated with ligands and mechanically-gated ion channels
C
The autonomic reflexes associated with pain are due to the activation of which ascending pathway?
a. Spinoreticular
b. Spinomesencephalic
c. Spinothalamic
d. Pontoamygdaloid pathway
A
As in any sensation, the intensity of pain can be
modulated by
a. the number of receptors activated
b. the frequency of firing sensory units
c. contextual features
d. AOTA
D
Which statement is true of visceral pain?
a. the receptors for visceral pain are distinct from somatic pain receptors
b. the visceral receptors are rapidly adapting
c. there are more delta-A fibers than C fibers that innervate the viscera
d. visceral pain travels in same tract as somatic pain
D
Visceral referred pain can be explained by which mechanism or theory
a. facilitation theory
b. projection theory
c. the viscera having the same origin of innervation as the somatic structure
d. AOTA
D
Visceral pain afferents are most sensitive to the ff stimuli EXCEPT
a. Stretching
b. a cut
c. Anoxemia
d. Traction
B
The descending inhibitory control of pain arises from which of the ff structures?
a. periaqueductal grey area
b. serotonurgic pain neuron
c. noreadrenergic pain neuron
d. AOTA
D