Body senses and perceptual plasticity

Question 1

What are the three main somatosenses?

Answer 1

Cutaneous sense, organic (internal) sense and vestibular (already covered)

Question 2

What is cutaneous sense?

Answer 2

Sensitivity to stimuli that involve the skin.

E.g. pressure, vibration, heating/cooling, and events that cause tissue damage (pain).

Question 3

What is organic internal sense?

Answer 3

A sense modality that arises from receptors located within the inner organs of the body.

Question 4

What is proprioception?

Answer 4

Ability to sense position of the body and limbs.

Question 5

What is vestibular?

Answer 5

Perception of the body’s balance.

Question 6

What are the types of cutaneous receptors?

Answer 6

Free nerve endings, other specialised receptors.

Question 7

What are free nerve endings?

Answer 7

Found in both hairy and non-hairy skin e.g. on the palms or soles of feet. In hairy skin they surround hair follicles.

Question 8

What are the other specialised receptors that are cutaneous receptors?

Answer 8

Involved in the detection of mechanical stimuli such as stretch and vibrations, warmth/coolness and pain.

Question 9

What is the heaviest organ in the body and what does it do?

Answer 9

Skin- protects the organism by keeping damaging agents from penetrating the body.

Question 10

What is epidermis?

Answer 10

The outer layer of the skin which is made up of dead skin cells.

Question 11

What is dermis?

Answer 11

Below the epidermis and contains mechanoreceptors that respond to stimuli such as pressure, stretching and vibrations.

Question 12

What are the two types of mechanoreceptors?

Answer 12

Merkel receptor and Meissner corpuscle.

Question 13

What are Merkel receptors?

Answer 13

Fires continuously while stimulus is presented, responsible for sensing fine details.

Question 14

What are meissner corpuscles?

Answer 14

Fires only when a stimulus is first applied and when it is removed, responsible for controlling hand-grip.

Question 15

What are the two other types of mechanoreceptors located deeper in the skin?

Answer 15

Ruffini cylinder and Pacinian corpuscle.

Question 16

What are Ruffini cylinder receptors?

Answer 16

Fires continuous to stimulation, associated with perceiving stretching of the skin.

Question 17

What is the pacinian corpuscle?

Answer 17

Fires only when stimulus is first applied and when it is removed, associated with sensing rapid vibrations.

Question 18

What are the internal senses?

Answer 18

Sensory nerve endings located in our internal organs, bones and joints.

Question 19

What are specialised receptors in the internal senses?

Answer 19

Include, muscle spindles that detect changes in muscle length and mechanoreceptors that respond to the movement and the angles of our joints.

Question 20

What is the sum of all the sensations in the internal senses?

Answer 20

Proprioception.

Question 21

How is tactile acuity achieved?

Answer 21

There is a high density of Merkel receptors in the fingertips, similar to cones in the fovea, results from both two-point thresholds and grating acuity studies are consistent with the density of Merkel receptors.

Question 22

What do areas with more acuity have?

Answer 22

Larger areas of cortical tissue and smaller receptive fields on the skin,