PNS WI18- Dermatomes, Receptors And Reflexes

Question 1

Strip of skin innervated by a single spinal nerve.

Answer 1

Dermatomes

Question 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

Answer 2

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

Question 3

Definition: A cell that respond to a stimulus

Answer 3

Sensory receptor

Question 4

Definition: Territory from which a sensory unit can excited.

Answer 4

Receptive field

Question 5

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

Answer 5

Sensory unit

Question 6

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

Answer 6

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

Question 7

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

Answer 7

Larger receptive fields are in areas less sensitive

Question 8

Sensory transduction is described as?

Answer 8

Stimulus into an electrical signal

Question 9

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

Answer 9

Myelinated Type A

Question 10

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

Answer 10

Unmyelinated type c

Question 11

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

Answer 11

Receptors that respond quickly and maximally and stop when stimulus continues

Question 12

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

Answer 12

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

Question 13

Receptor classification by source:

Stimuli from outside environment

Answer 13

Exteroceptors

Question 14

Receptor classification by source:

Stimuli from internal environment

Answer 14

Interoceptors

Question 15

Receptor classification by source:

Receptor for position sense

Answer 15

Proprioceptors

Question 16

Receptor classification by function:

Receptor for pain/noxious sensation

Answer 16

Nocieceptors

Question 17

Receptor classification by function:

Temperature receptor

Answer 17

Thermoreceptor

Question 18

Receptor classification by function:

Physical deformation receptor; physical change

Answer 18

Mechanoreceptors

Question 19

Receptor types:

Free ending receptors

Answer 19

Free endings

Follicular

Merkel cell

Question 20

Receptor types:

Encapsulated receptor types

Answer 20

Meissner’s
Ruffini’s
Pacinian

Question 21

Receptor types:

Receptor type for pain and temperature that is slow adapting

Answer 21

Free endings

Question 22

Receptor types:

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

Answer 22

Follicular

Question 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

Answer 23

Merkel

Question 24

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

It is rapid adapting

Answer 24

Meissner

Question 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

Answer 25

Ruffini’s

Question 26

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

Answer 26

Pacinian

Question 27

Definition: predictable sensory to motor response to a stimulus.

Answer 27

Reflex

Question 28

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

Answer 28

No, humans need branches for each limb

Question 29

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

Answer 29

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

Question 30

T/F: Muscle spindles are a type stretch receptor

Answer 30

True

Question 31

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

Answer 31

Extrafusal (fibers outside the spindle)

Question 32

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

Answer 32

Intrasfusal

Question 33

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

Answer 33

Nuclear chain

Question 34

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

Answer 34

Nuclear bag

Question 35

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

Answer 35

Gamma motor neurons (stretch)

Question 36

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

Answer 36

Annulospiral: around the middle of spindle Flower spray: spreads out to junction of contractile and nuclear part of the muscle fiber

Question 37

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

Answer 37

Rate of stretch (speed)

Question 38

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

Answer 38

Degree of stretch

Question 39

Active activation of muscle spindles is produced by ?

Answer 39

Fusimotor fibers

Question 40

Examples of passive activation of muscle spindles

Answer 40

Knee jerk-tendon stretched Monosynaptic-excitatory Polysynaptic- inhibitory antagonistic muscle

Question 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 ```

Answer 41

Golgi tendon organ

Question 42

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

Answer 42

Free ending unmyelinated nerve fibers Excitatory reflex

Question 43

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

Answer 43

Simultaneous and opposite pattern of activity in the contralateral limb