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Flashcards in Receptors Deck (77):
1

What brain structure is required to perceive sensation?

- The cerebral cortex

2

How can afferent information control movement?

- Flexor reflexes

3

How does afferent information maintain arousal?

- Sensory information acts on the reticular formation to send stimuli to the cerebral cortex

4

What is a receptor?

Transducer that changes physical and chemical stimuli into electrical nerve impulses

5

What are the 4 receptor stimulus qualities?

- Modality
- Intensity
- Duration
- Location

6

What is modality?

- A labelled line code/ type of stimulus

(i.e. vision, hearing, touch, taste, smell)

7

What is intensity?

Frequency of stimulus

8

What is duration?

Relationship between stimulus intensity, and percieved intensity.

9

What is location?

The location of the receptor (Where it resides, and what type of discharges)

10

What 3 factors influence modalities and qualities of sensory receptors?

- Temporal and spatial patterns of activation
- Specificity of sensory endings
- Central connections (Where does the receptor project to in the CNS?; Brain has different areas for different types of signals)

11

What is meant by temporal activation?

How fast is the stimulus firing.

12

What is meant by spatial activation?

How many stimuli are present over the given tissue area.

13

What is meant by "labeled line"?

- Certain receptors primarily respond to a certain type of stimuli

14

What are the 5 major sensory modalities?

- Vision
- Hearing
- Smell
- Taste
- Somatic

15

What are examples of sub-modalities of vision?

- Color
- Motion

16

What are examples of submodalities of hearing?

- Pitch

17

What are examples of sub-modalities of smell?

The over 20 different types of odor

18

What are examples of sub-modalities of taste?

- Sweet, sour, salty, bitter, "umami"

19

What are examples of sub-modalities of somatic sense?

- Touch-pressure
- Warm-cold
- Flutter-vibration
- Pain
- Itch
- Tickle
- Position and movement senses

20

How is a higher amplitude stimulus interpreted by a sensory receptor? What is this called?

- A more intense stimulus leads to a higher rate of action potentials (all the same amplitude, but more frequent)
- Can be stimulated temporally or spatially
- Called rate coding

21

What is a topographic/ (somatotopic) map?

Specific areas of the brain correspond to specific areas on the body

22

What are the 3 anatomic classifications of sensory receptors?

- Exteroceptor
- Proprioceptor
- Interoceptor

23

Where are exteroceptors located?

- On external body surfaces in the cutaneous or subcutaneous tissue

24

Where are proprioceptors located?

- In tendons, joints, ligaments, and fascia/ deep tissue

25

Where are interoceptors located?

- On autonomic structures such as glands and organs

26

What qualities of sensation are received by exteroreceptors?

- Think of where they are located

- Touch
- Pressure
- Pain
- Temperature
- Smell
- Vision
- Hearing

27

What qualities of sensory input are received by proprioceptors?

- Position sense
- Movement sense

28

What qualities of sensory input are recieved by interoceptors?

- Digestion
- Excretion
- Circulation
- Respiration
- Taste
- Pain
- Visceral sensations

29

What are the 6 physiologic classifications of sensory receptors?

- Mechanoreceptors
- Thermoreceptors
- Photoreceptors
- Chemoreceptors
- Pain receptors
- Nociceptors

30

What are the 2 types of adaptation?

- Slow adaptation
- Fast adaptation

31

What is the novel stimulus of a mechanoreceptor?

- Physical or mechanical stimuli

32

What is the novel stimulus of a thermoreceptor?

- Temperature

33

What is the novel stimulus of a photoreceptor?

- Light

34

What is the novel stimulus of a nociceptor?

- Tissue damage

35

What is the difference between a fast and slow adapting receptor?

- A rapid adapting fiber quickly returns to a "base level", and then spikes again when the stimulus is removed
- A slowly adapting fiber takes longer to return to base state of excitation, and doesn't respond to a removal of stimulus

36

Which receptors are more for timing detection?

Fast adapting

37

Which receptors are more for spatial detection?

Slow adapting

38

Are large receptive field neurons found in areas of high or low sensitivity?

- Found in areas of low sensitivity

39

Are small receptive field neurons found in areas of high or low sensitivity?

- Areas of high sensitivity

40

Second order neurons create a larger receptive field using information from what?

- The convergence of several 1st order receptor neurons

41

How is 2 point discrimination explains using receptive fields?

Each point must be in a separate receptive field to be discriminated.

42

What does it mean if a receptor is encapsulated?

- It is covered in connective tissue

43

What are 2 types of non-encapsulated mechanoreceptors?

- Free nerve endings (for pain, thermo, and chemo)
- Hair follices (touch)

44

What is the name of the encapsulated mechanoreceptor for touch?

Meissner's corpuscles

45

What is the name of the encapsulated mechanoreceptor for temperature/ cold?

Krause's End Bulbs

46

What is the name of the encapsulated mechanoreceptor for kinesthetic sense/ pressure?

Ruffini End Organs

47

What is the name of the encapsulated mechanorecept for Touch and Vibration?

Pacinian Corpuscles

48

What is the name of the encapsulated mechanoreceptor for stretch?

Muscle spindle

49

What is the name of the encapsulated mechanoreceptor for tension?

Golgi Tendon Organ

50

Where are Ruffini Endings located?

Only within the glabrous dermis and subcutaneous tissue of humans.

51

What are Ruffini Endings particularly sensitive to, and what is their theorized main function?

- Sensitive to skin stretch, and though to contribute to kinesthetic sense and control of finger position and movement.

52

Are Ruffini Endings rapidly or slowly adapting mechanoreceptors?

Slowly

53

Do Ruffini Endings have large or small receptive fields?

Large

54

What are Meissner's Corpuscles sensitive to?

Light touvh

55

Where are Meissner's Corpuscles located?

- Just beneath the epidermi throughout the skin, but concentrated in fingertips, palms, soles, lips, tongue, face, and other areas that are especially sensitive to touch

56

Are Meissner's Corpuscles rapdily or slowly adaptive mechanoreceptors?

Rapidly (Sensation is always changing)

57

Do Meissner's Corpuscles have large or small receptive fields?

Small.

58

Why are Pacinian corpuscles the most studied receptor?

Because they are so large

59

What are Pacinian Corpuscles sensitive to?

- Deep pressure
- Touch
- High frequency vibration

60

What makes up the capsule of the Pacinian Corpuscles?

20 - 60 layers of concentric lamellae composed of fibrous connective tissue, fibroblasts, and separated by gelatinous material.

61

What are the lamellae of the Pacinian Corpuscles?

Very thin, flat, modified, Schwann Cells

62

Where are Pacinian Corpuscles found?

In deep subcutaneous tissue

63

Are Pacinian Corpuscles rapidly or slowly adapting mechanoreceptors?

Rapidly adapting

64

Do Pacinian Corpuscles have a large or small receptive field? What is special about its field?

Large receptive field with an especially sensitive center

65

How large is a Pacinian Corpuscle?

1 mm

66

What are Merkel Nerve Endings sensitive to?

- Touch
- PRESSURE and TEXTURE

67

Where are Merkel Nerve Endings located?

- In the superficial skin layers
- Clustered beneath ridges of fingertips that make up finger tips

68

What frequency vibration are Merkel Nerve endings especially sensitive to?

5 - 15 Hz

69

Are Merkel Nerve Endings rapidly or slowly adapting mechanoreceptors?

Slowly

70

Do Merkel Nerve Endings have large or small receptive fields?

Small

71

How many Merkel Nerve Endings may one affterent nerve fiber innervate?

Up to 90

72

What is the most abundant receptor?

Free nerve endings

73

Where are free nerve endings located?

In skin
- Penetrate epidermis and end in the stratum granulosum

74

Are free nerve endings rapidly or slow adapting mechanoreceptors?

Can be either, or intermediate

A5 are rapidly, and C are slowly

75

What are free nerve endings sensitive to?

- Temperature
- Mechanical stimuli
- Pain

76

Since free nerve endings are sensitive to different types of pain, what is it termed?

Polymodal

77

Are free nerve endings always encapsulated?

No.