8. TOUCHING Flashcards
(56 cards)
1
Q
- What is the skin?
A
- it is an organ of tactility
2
Q
- What does the skin allow?
A
- it allows us to feel and sense our environment in different ways
3
Q
- What three distinct senses does the skin account for?
A
- responding to pressure
- responding to temperature
- responding to pain
4
Q
- What are the four reasons for dividing the skin into three different senses?
A
- the skin responds differently to a distinct class of stimuli
- the skin has the ability to discriminate among these
stimuli - the skin possesses a distinct set of receptors
- this leads to experiences that differ phenomenologically
when the sense is stimulated
5
Q
- Provide a definition for pressure.
A
- physical pressure on the skin
- this is the stimulus for sensed pressure
6
Q
- Provide a definition for temperature.
A
- the temperature on our skin
- this is the stimulus for temperature
7
Q
- Provide a definition for pain.
A
- this is any stimulus that is intense enough to cause tissue damage
- it may be in the form of:
- pressure
- temperature
- electric shock
- irritant chemicals
8
Q
- What three main layers does the skin consist of?
A
- the epidermis
- the dermis
- the hypodermis
9
Q
- What do the terms “epi” and “dermis” mean in Greek?
A
- “epi” = over / upon
- “dermis” = skin
10
Q
- What does the Epidermis form?
A
- it forms the water proof, protective wrap
- this wrap is found over the body’s surface
- this wrap serves as a barrier to infection
11
Q
- What is the protective Epidermis wrap over the body’s surface made up of?
A
- it is made up of stratified squamos epithelium
- it has an underlying basal lamina
12
Q
- Where is the Dermis located?
A
- it is the skin layer beneath the epidermis
13
Q
- What does the Dermis consist of?
A
- it consists of epithelial tissue
14
Q
- What is the function of the dermis’s epithelial tissue?
A
- it cushions the body from stress and strain
15
Q
- What tightly connects the dermis to the epidermis?
A
- a basement membrane
- this membrane harbours many nerve endings
16
Q
- What does the basement membrane provide?
A
- it provides a sense of touch and heat
17
Q
- Is the Hypodermis a part of the skin?
A
- NO
18
Q
- Where is the Hypodermis located?
A
- it lies below the dermis of the cutis
19
Q
19.What is the purpose of the Hypodermis?
A
- it is to attach the skin to the underlying bone and muscle
- it also supplies the skin with blood vessels and nerves
20
Q
- What is found in the Dermis?
A
- various nerve fibres
- various nerve corpuscles
21
Q
- What do the nerve fibres and the nerve corpuscles of the dermis target?
A
- they target the detection of environmental/external stimuli
on the surface of the skin
22
Q
- What are different peripheral sensory receptors sensitive to?
A
- particular types of stimulus
23
Q
- What happens when the peripheral sensory receptors detect particular sensations?
A
- they are sensitive to these sensations
- they generate new nerve impulses
24
Q
- Where will these new nerve impulses go to if the stimulation is on the lower part of the body?
A
- they will go to the spinal cord
25
25. Where will these new nerve impulses go to if the stimulation is on the upper part of the body or the face?
- they will go to the brain
- via the cranial nerves
26
26. Where will all the information regarding stimulation end up?
- the sensory cortex of the brain
27
27. Where is the stimulation felt?
- in the brain
28
28. Where are the nerve impulses generated?
- in the dermis
29
29. Where will the information of the stimulations felt on the right side of the body end up?
- in the left sensory cortex
- in the parietal lobe of the brain
30
30. Where will the information of the stimulations felt on the left side of the body end up?
- in the right sensory cortex
- in the parietal lobe of the brain
31
31. What is located at the very bottom of the epidermis?
- the Merkel Cells
- they are very small sensory cells
32
32. What connects the Merkel cells to each other?
- Merkel cell discs
33
33. Are there any other nerve fibres in the epidermis, other than the Merkel cells?
- NO
34
34. What are the Merkel cells sensitive to?
- light touch
35
35. What do the Merkel Cells do when they detect light touch?
- they detect this type of information in the epidermis
- they carry this information to the brain
36
36. What do Merkel cells provide information on?
- pressure
- position
- deep static touch features
(shapes / edges)
37
37. What detects all mechanical stimuli?
- mechanoreceptors
38
38. What is an example of mechanoreceptors in the epidermis?
- Corpuscular Peripheral Sensory Receptors
39
39. What size are Corpuscular Peripheral Sensory Receptors (mechanoreceptors)?
Where are they located?
- they are moderately small
- they are located in the dermal papillae
- this is near the surface of the dermis
40
40. What is the specific name of these Corpuscular Peripheral Sensory Receptors?
- Meissner Corpuscles
41
41. What are Meissner Corpuscles responsible for?
- they are responsible for transmitting the sensations of:
- fine
- discriminative (accurate distinctions)
- touch and vibrations
42
42. What can be found deeper down in the dermis?
(it can be found even in the hypodermis)
- quite large receptors
- they consist of numerous layers
- they are made up of specialised Schwann cells
- they are laminated sensory corpuscles
- they are called Pacinian Corpuscles
42
44. What are Pacinian Corpuscles responsible for?
- sensitivity to vibration and pressure
43
45. What are the Pacinian Corpuscles connected to?
- dendrites of sensory neurones
44
46. What does the connection between the Pacinian Corpuscles and the dendrites of sensory neurons result in?
- mechanical information can now be transferred towards the brain
45
47. What exactly do Pacinian Corpuscles detect?
- the pressure on the skin
- NOT the touch
46
48. Why are the Pacinian Corpuscles near the base of the dermis?
- they only fire off to generate new nerve impulses when
there is significant pressure
47
49. What allows the skin to be sensitive to temperature?
- thermoreceptors
48
50. What are the two types of thermoreceptors?
- those that detect heat
- those that detect cold
49
51. Are thermoreceptors corpuscular.
Why or why not?
- they are not
- they are just free nerve endings
- they can be situated close to each other
50
52. What allows the skin to be sensitive to pain?
- specialised pain receptors
51
53. What are these specialised pain receptors called?
- nociceptors
52
54. What do Nociceptors detect?
- they detect noxious stimuli
(NOXIOUS= harmful, poisonous)
- they detect the extent of pain
53
55. Are Nociceptors corpuscular?
- no
- they are just free nerve endings in the dermis
- the presence of these nociceptors in the dermis
is what makes it sensitive to pain
- this is why partial thickness injuries are so painful
54
56. What are two examples of partial thickness injuries?
- cuts
- burns
55
57. Do the Nociceptors go into the epidermis?
- no
