NRS 301 Exam 3 questions well
answered to pass
How do mechanoreceptors vary? - correct answer ✔✔receptive field size, preferred stimuli
frequency, stimulus sensitivity (heat pressure, vibration, stretch)
what are the different type of somatic sensory stimuli - correct answer ✔✔touch,
proprioception, temperature, pain
each is distinct
Pacinian corpuscles - correct answer ✔✔deep pressure and vibration, large receptive field,
rapidly adapting fiber, sensitive to on/off, not sensitive duration
how do receptive fields vary - correct answer ✔✔they vary by type of mechanoreceptors and
the size of the field
2 point discrimination - correct answer ✔✔the smallest distance between points that can be
discerned or perceived
depends on density of mechanoreceptors in the skin and the size of their receptive fields
sensory adaptation - correct answer ✔✔the progressive loss of receptor response as
stimulation is maintained
stimulus is encoded by firing rate of receptor
Adaptation rate of mechanorecptors - correct answer ✔✔slowly adapting fibers- keep
responding as long as the stimuli is present, sensitive to duration
, rapidly adapting fibers- respond to stimulation with a burst of firing at beginning and end but
not duration, sensitive to changes and vibrations
How do mechanosensitive channels work? - correct answer ✔✔channels open by stretch,
external force, or internal force, then they transduce a cellular signal, they turn mechanical
energy to ionic current
Afferents - correct answer ✔✔bringing information to the CNS, enter through dorsal roots and
have cell bodies in dorsal root ganglion
How does information flow in pathways? - correct answer ✔✔information from periphery to
cortex through different steps which occur at synapses, first, second and third order, each step
can transform information
What are the difference between primary somatosensory afferents? - correct answer ✔✔vary
widely in diameter and myelination level, speed is determined by diameter and myelination,
faster to slower receptors include proprioreceptors, mechanoreceptors, pain, temperature, and
itch
Dermatomes - correct answer ✔✔segmental organization of spinal nerves, a dermatome is the
area of the skin that is innervated by the dorsal roots of a single spinal cord section
what are the 4 segments of the spinal cord and where are their nerves located? - correct answer
✔✔cervical- high neck, chest and arms
thoracic- body midsection to waist
lumbar- waist to legs
sacral- genitals and ankles
Somatosensory cortex - correct answer ✔✔Brodmans area 3b, dense input from vp of nucleus
of thalamus
answered to pass
How do mechanoreceptors vary? - correct answer ✔✔receptive field size, preferred stimuli
frequency, stimulus sensitivity (heat pressure, vibration, stretch)
what are the different type of somatic sensory stimuli - correct answer ✔✔touch,
proprioception, temperature, pain
each is distinct
Pacinian corpuscles - correct answer ✔✔deep pressure and vibration, large receptive field,
rapidly adapting fiber, sensitive to on/off, not sensitive duration
how do receptive fields vary - correct answer ✔✔they vary by type of mechanoreceptors and
the size of the field
2 point discrimination - correct answer ✔✔the smallest distance between points that can be
discerned or perceived
depends on density of mechanoreceptors in the skin and the size of their receptive fields
sensory adaptation - correct answer ✔✔the progressive loss of receptor response as
stimulation is maintained
stimulus is encoded by firing rate of receptor
Adaptation rate of mechanorecptors - correct answer ✔✔slowly adapting fibers- keep
responding as long as the stimuli is present, sensitive to duration
, rapidly adapting fibers- respond to stimulation with a burst of firing at beginning and end but
not duration, sensitive to changes and vibrations
How do mechanosensitive channels work? - correct answer ✔✔channels open by stretch,
external force, or internal force, then they transduce a cellular signal, they turn mechanical
energy to ionic current
Afferents - correct answer ✔✔bringing information to the CNS, enter through dorsal roots and
have cell bodies in dorsal root ganglion
How does information flow in pathways? - correct answer ✔✔information from periphery to
cortex through different steps which occur at synapses, first, second and third order, each step
can transform information
What are the difference between primary somatosensory afferents? - correct answer ✔✔vary
widely in diameter and myelination level, speed is determined by diameter and myelination,
faster to slower receptors include proprioreceptors, mechanoreceptors, pain, temperature, and
itch
Dermatomes - correct answer ✔✔segmental organization of spinal nerves, a dermatome is the
area of the skin that is innervated by the dorsal roots of a single spinal cord section
what are the 4 segments of the spinal cord and where are their nerves located? - correct answer
✔✔cervical- high neck, chest and arms
thoracic- body midsection to waist
lumbar- waist to legs
sacral- genitals and ankles
Somatosensory cortex - correct answer ✔✔Brodmans area 3b, dense input from vp of nucleus
of thalamus
