Deck 27: Cutaneous Sensory Systems

Question 1

Most somatosensory information is transmitted to the CNS via the

A) Reticular activating system
B) Anterolateral tract
C) Dorsal column pathway
D) Anterior comm issures
E) Lateral spinothalamic tract

Answer 1

C

Question 2

The area of skin whose sensory input enters the spinal cord at a single segment is called a

A) myotome
B) dermatome
C) sclerotome
D) re ce ptiv e fie ld
E) somatotopic representation

Answer 2

B

Question 3

Sensing of one modality as another is called

A) para norm al activity
B) intuition
C) foresight
D) syn esth esia
E) labeled line

Answer 3

D

Question 4

The quality of a sensory stimulus is generally encoded by

A) population of neurons firing and their frequency of firing
B) conne ctivity of sensory neurons in the spinal cord
C) connectivity of sensory fibers in the central nervous system
D) size of t he ac tion po ten tials
E) the receptive field of sensory neurons

Question 5

Primary somatosensory neurons that serve the lower half of the body mak e synapses in the

A) Fa sic ulu s g ra cilis
B) Nu cleu s gr acilis
C) Fasiculus cuneatus
D) Nucleus cuneatus
E) Thalamus

Question 6

Fast-adapting fibers best detect

A) su sta ine d s tim uli
B) slo wly c ha ng ing stim uli
C) on set o f stim uli
D) tur nin g o ff o f s tim uli
E) low fre qu en cy s tim uli

Question 7

A push or pull on the skin is best detected by

A) Pacinian corpuscles
B) Meissner's corpuscles
C) Merkel's disks
D) Ruffini's corpuscles
E) free nerve endings

Question 8

Sensory afferents for touch help relieve pain by

A) excitin g inh ibitory inte rneu ron s for p ain in th e sp inal co rd
B) inh ibitin g re ce pto r po ten tials for pa in
C) inh ibitin g g en er ato r po ten tials for pa in
D) activating motor units through the withdrawal reflex
E) they do not do this, tricky question person

Question 9

Pain and temperature information crosses over to the other side of the CNS in the

A) m ed ulla
B) thalamus
C) spinal cord at the level of entry of the spinal nerve
D) pons
E) cerebrum

Question 10

The som atosensory cortex is located in the

A) Post-central gyrus of the parietal lobe
B) Pre-central gyrus of the frontal lobe
C) Insular lobe
D) Sub-lateral fissure of the temporal lobe
E) Broca's area

Question 11

"First pain" is carried by

A) Large myelinated fibers classified as Aþ
B) Large unm yelinated fibers ð
C) Small myelinated fibers classified as A
D) Small unmyelinated fibers classified as C
E) Both large and sm all unmyelinated fibers

Question 12

Crossing over (decussation) of somatosensory afferent information occurs in the

A) Spinal cord at the level of entry of the spinal nerves
B) Dorsal column pathway
C) M ed ulla
D) Thalamus
E) Cerebral cortex

Question 13

The ce ll bo die s o f m os t pr im ar y so m ato se ns or y aff er en t ne ur on s a re fou nd in

A) do rsal ro ot g an glia
B) ventral horn of the spinal cord
C) nu cle us cu ne atu s o r gr ac ilis
D) thalamus
E) post-central gyrus

Question 14

High frequency vibration on the skin is best detected by

A) Pacinian corpuscles
B) Meissner's corpuscles
C) Merkel's disks
D) Ruffini's corpuscles
E) free nerve endings

Question 15

The rec ep tive field for so m ato se ns or y sys tem is

A) The area of the skin that, when stimulated, alters neuronal excitation
B) The area of the skin directly innervated by primary somatosensory neurons
C) The area of the skin where stimulation inhibits adjacent somatosensory neurons
D) T he are a o f th e c or tex in w hic h n eu ro ns are fou nd tha t co rre sp on d to are as of t he sk in
E) The area of the skin where stimulation excites adjacent somatosensory neurons

Question 16

The m ain fu nction of later al inhibition is to

A) limit pain transmission
B) sharpen sensory discrimination
C) cause adaptation
D) shut off sensory input
E) enhance alertness by focusing attention

Question 17

Intensity of sensory stimuli are encoded by

A) population of neurons firing and their frequency of firing
B) conne ctivity of sensory neurons in the spinal cord
C) connectivity of sensory fibers in the cerebrum
D) size of t he ac tion po ten tials
E) the receptive field of sensory neurons

Question 18

Primary somatosensory neurons that serve the torso of the body mak e synapses in the

A) Fa sic ulu s g ra cilis
B) N uc leu s g ra cilis
C) Fasiculus cuneatus
D) Nucleus cuneatus
E) Thalamus

Question 19

The ability to distinguish between two cutaneous stimuli is called

A) sen sitivity
B) two-point discrimination
C) adaptation
D) lateral inhibition
E) W eber-Fechner Law

Question 20

The ab ility to d isc rim ina te b etw ee n tw o s tim uli S 1 and S2 depends on

A) the absolute value of 6 S = S
B) the value of S1 and S2 on ly
C) the relative va lue of 6 S to S
D) the value of log S1 2
E) the value of S1