Sensory Systems

Question 1

This type of receptor is located beneath the epidermis of the fingers, palm of the hand, toes, and plantar surface of the feet (glabrous skin). They are low-threshold, rapidly adapting mechanoreceptors sensitive to touch and low-frequency vibration

Answer 1

Meissner’s Corpuscles

Question 2

These receptors are located in the basal layer of the epidermis, especially on the lips, distal parts of the extremities, and external genital organs (glabrous skin). They are low-threshold, slowly adapting mechanoreceptors sensitive to pressure stimuli

Answer 2

Merkel’s Receptors (disks)

Question 3

These receptors are located deep in the dermis layer of both hairy and glabrous skin. They consist of concentric lamellae of flattened cells. They are low-threshold, rapidly adapting, and are sensitive to rapid indentation of the skin caused by high frequency vibration

Answer 3

Pacinian Corpuscles

Question 4

These receptors are located in the dermis layer of both hairy and glabrous skin and are widely distributed. They are low-threshold, slowly adapting, and sensitive to stretching of the skin. They provide information about the magnitude and direction of stretch.

Answer 4

Ruffini’s corpuscles (endings)

Question 5

Conscious proprioception is believed to rely predominantly on joint receptors. These receptors in ligaments and joint capsules consist of ____ or _____

Answer 5

Free nerve endings, encapsulated receptors

Question 6

Nonconscious proprioception relies primarily on ____ and ____ as receptors

Answer 6

Muscle spindles, GTOs

Question 7

The one sensory pathway that can make its way to the cortex without synapsing in the thalamus is the ____ system

Answer 7

Olfactory (smell)

Question 8

The largest (1a and 1b) myelinated nerve fibers are from ____ and ____ respectively

Answer 8

Annulospiral endings of the muscle spindle, GTOs

Question 9

Type II, A-Beta myelinated nerve fibers are from what receptors?

Answer 9

Cutaneous tactile receptors (Meissner’s, Merkel’s, etc.),

Flower-spray endings of the muscle spindles

Question 10

Type III, A-Delta myelinated nerve fibers are from what receptors?

Answer 10

Crude touch, pain and temperature sensations

Question 11

Type IV, C (unmyelinated) nerve fibers transmit what sensations?

Answer 11

Pain and temperature

Question 12

The VPL of the thalamus relays somatosensory information from the ____

Answer 12

Body

Question 13

The VPM of the thalamus relays somatosensory information from the ____

Answer 13

Face

Question 14

The anterior limb of the internal capsule contains what fibers?

Answer 14

Corticopontine (frontal, parietal, temporal, occipital)

Question 15

The posterior limb of the internal capsule contains what fibers?

Answer 15

Sensory/motor fibers to/from the BODY (conscious, obviously)

Question 16

The “genu” of the internal capsule contains what fibers?

Answer 16

Sensory/motor fibers to/from the FACE (corticobulbar)

Question 17

The primary sensory cortex consists of Brodmann areas _____

Answer 17

3,1,2 (post-central gyrus, parietal lobe)

Question 18

The primary motor cortex consists of Brodmann areas _____

Answer 18

4,6 (Pre-central gyrus, parietal lobe)

Question 19

The primary vision cortex consists of Brodmann areas ____

Answer 19

17,18,19 (posterior cortex/occipital lobe)

Question 20

The primary auditory cortex consists of Brodmann areas ____

Answer 20

41, 42 (lateral temporal lobe)

Question 21

The primary afferent for the spinothalamic tract enters the dorsal horn and synapses in the ____ or ____ onto the 2nd order neuron

Answer 21

Substantia gelatinosa, nucleus proprius

Question 22

This nucleus contains the primary afferent cell bodies projecting from the TMJ and muscles of mastication through the mandibular branch of V. It is the ONLY spot in the CNS to contain pseudounipolar cell bodies

Answer 22

Mesencephalic nucleus of V