Cutaneous Receptors

Question 1

Which areas of the hand are ruffini endings typically located?

Answer 1

Along the palmar folds of the hands as well as finger joints as these areas of skin typically stretch the most.

Question 2

What type of tactile information do ruffini endings transfer?

Answer 2

Info regarding the shape of large objects grasped with entire hand as well as hand and finger mvmt when hand is empty.

Question 3

Which layer of the skin are ruffini endings typically located?

Answer 3

The dermis.

Question 4

RA2 receptor…?

Answer 4

Pacinian Corpuscle

Question 5

What stimulus best activates ruffini endings?

Answer 5

Skin stretch

Question 6

Which receptor type contributes towards braille?

Answer 6

RA1 meisner corpuscle

Question 7

What stimulus best activates Meissner corpuscles?

Answer 7

Lateral motion

Question 8

RA1 receptor…?

Answer 8

Meissner Corpuscle

Question 9

What type of tactile information do merkel discs transfer?

Answer 9

Info regarding the shape, size, surface area and texture of objects.

Question 10

SA1 receptor…?

Answer 10

Merkel Disk

Question 11

How do Pacinian corpuscles contribute towards our sense of touch?

Answer 11

• Contribute towards our dynamic sensitivity of touch
• Filter + amplify high frequency vibrations of tactile stimuli - Allow us to feel the vibrations of handheld tools as they
  move over object surfaces as if our own fingers were
  touching the surface themselves

Question 12

Which is the most sensitive mechanoreceptor?

Answer 12

Pacinian corpuscle

Question 13

What stimulus best activates Pacinian corpuscles?

Answer 13

(High frequency) vibrations

Question 14

Which layer of the skin are Pacinian corpuscles typically located?

Answer 14

Deep tissue of the dermis.

Question 15

Which layer of the skin are Meissner corpuscles typically located?

Answer 15

The dermal papillae (close to the skin surface).

Question 16

What stimulus best activates merkel disks?

Answer 16

Edges, points, corners…

Question 17

What type of events do Meissner corpuscles detect?

Answer 17

Low-frequency and low-amplitude skin motion ie. hand motion over object surfaces.

Question 18

SA2 receptor…?

Answer 18

Ruffini Ending

Question 19

Which layer of the skin are merkel discs typically located?

Answer 19

The tips of epidermal sweat ridges.

Question 20

Describe the receptive fields of Type I fibres.

Answer 20

• Small and highly localised
• Multiple spots of sensitivity which reflects axon branching
• High density in fingers
• Significantly smaller than most objects that hand touches
• Only detect small portion of objects

Question 21

Define tactile acuity

Answer 21

The ability to resolve spatial details of textured surfaces.

Question 22

Where is tactile acuity the highest?

Answer 22

In the fingertips where the receptive fields are the smallest.