PNS WI18- Dermatomes, Receptors And Reflexes Flashcards Preview

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Flashcards in PNS WI18- Dermatomes, Receptors And Reflexes Deck (43):
1

Strip of skin innervated by a single spinal nerve.

Dermatomes

2

Cord levels and cutaneous area of innvervation:

1. C5
2. C6
3. C7.
4. C8
5. T4
6. T10
7. L5
8. S1
9. S2

1. Upper arm (lateral)
2. Thumb and lateral forearm
3. Middle finger
4. Little finger
5. Nipple
6. Umbilicus
7. Big toe
8. Heel
9. Back of thigh

3

Definition: A cell that respond to a stimulus

Sensory receptor

4

Definition: Territory from which a sensory unit can excited.

Receptive field

5

Definition: The receptor, all endings and motor unit combined.

Sensory unit

6

What is the relationship between the receptive field and sensory unit?

The receptive field is the area where the sensory unit can be stimulated

7

What is the correlation between the size of the receptive field and sensitivity?

Larger receptive fields are in areas less sensitive

8

Sensory transduction is described as?

Stimulus into an electrical signal

9

Discriminative touch and kinesthetic stimuli are carried by which type of axon

Myelinated Type A

10

Pain, touch and temperature are carried by what type of axon?

Unmyelinated type c

11

Rapidly adapting receptors is also know as phasic. How is it described?

Receptors that respond quickly and maximally and stop when stimulus continues

12

Slowly adapting receptors are also known as tonic. How are they described?

Receptors continue to respond to stimulus as long as its there.

13

Receptor classification by source:

Stimuli from outside environment

Exteroceptors

14

Receptor classification by source:

Stimuli from internal environment

Interoceptors

15

Receptor classification by source:

Receptor for position sense

Proprioceptors

16

Receptor classification by function:

Receptor for pain/noxious sensation

Nocieceptors

17

Receptor classification by function:

Temperature receptor

Thermoreceptor

18

Receptor classification by function:

Physical deformation receptor; physical change

Mechanoreceptors

19

Receptor types:

Free ending receptors

Free endings

Follicular

Merkel cell

20

Receptor types:

Encapsulated receptor types

Meissner’s
Ruffini’s
Pacinian

21

Receptor types:

Receptor type for pain and temperature that is slow adapting

Free endings

22

Receptor types:

Receptor type that are wrapped around hair follicles, are activated when hair is moved and are rapid adapting.

Follicular

23

Receptor type:

Receptor type that serves as an edge detector, allowing you also know how much pressure to apply to thing.

It is Slow adapting

Merkel

24

Receptor type that is located in the dermis, in the papillae and respond to light touch.

It is rapid adapting

Meissner

25

Receptor types that requires significant force to respond and respond to shearing forces against the body like heavy winds.

It is is slow adapting

Ruffini’s

26

Receptor type that is deeper within the dermis and responds to vibration.

It is rapid adapting

Pacinian

27

Definition: predictable sensory to motor response to a stimulus.

Reflex

28

Reflexes are unconscious. In animals the sensory and motor limbs are the same branch. Is that the case with humans?

No, humans need branches for each limb

29

How would you describe the motor innervation of areas that perform intricate vs gross movement?

Motor units are required in intricate movements and less in areas with more gross movement.

30

T/F: Muscle spindles are a type stretch receptor

True

31

Muscle spindle that is a typical skeletal muscle fiber, voluntary and innervated by alpha motor neuron

Extrafusal (fibers outside the spindle)

32

Muscle spindle fiber that is inside the spindle which has end that contract but the middle doesn’t.

It is multinucleated.

Intrasfusal

33

When the nuclei inside the intrafusal fiber are lined up, it is referred to as?

Nuclear chain

34

When the nuclei in the intrafusal fiber are bunched together, it is referred to as ?

Nuclear bag

35

Where does the motor innervation of of the intrafusal fibers come from?

Gamma motor neurons (stretch)

36

What are two types of sensory fibers types around muscle spindle?

Annulospiral: around the middle of spindle

Flower spray: spreads out to junction of contractile and nuclear part of the muscle fiber

37

Primary/annulospiral endings sensory supply to muscle spindle account for?

Rate of stretch (speed)

38

Secondary/ flower spray endings sensory supply to to muscle spindle accounts for ?

Degree of stretch

39

Active activation of muscle spindles is produced by ?

Fusimotor fibers

40

Examples of passive activation of muscle spindles

Knee jerk-tendon stretched

Monosynaptic-excitatory

Polysynaptic- inhibitory antagonistic muscle

41

What is
• Found at muscle-tendon junctions
• Measures the force of the contraction
• Autogenic inhibition
• Protects muscle from excessive contraction • Fine adjustments in the force of muscle contraction

Golgi tendon organ

42

Innervation of joints in the ligaments, capsules and menisci is done by?

Free ending unmyelinated nerve fibers

Excitatory reflex

43

Flexor/withdrawal reflex involves the whole limb, therefore several spinal segments. Define the crossed effects.

Simultaneous and opposite pattern of activity in the contralateral limb