Proprioception

Question 1

limb position sense

Answer 1

knowing the position of a joint or joints - “static” position

Question 2

kinesthesia

Answer 2

joint movement - “dynamic”

information about movement speed, direction

Question 3

proprio more sensitive in active or passive movement?

Answer 3

active

Question 4

What receptors contribute to proprioception

Answer 4

joint receptors
stretch receptors
cutaneous receptors

Question 5

Where are joint receptors

Answer 5

joint capsule, ligaments

Question 6

receptors - rapidly adapting response to movement

Answer 6

golgi-mazzoni corpuscle

paciniform corpuscle

Question 7

receptors - slowly adapting response to stretch

Answer 7

golgi organ

ruffini ending

Question 8

receptors - free nerve ending

Answer 8

nociceptor

Question 9

Are joint receptors more active in extreme range of joint rotation?

Answer 9

Yes

“limit” detectors, possible protective function

Question 10

What are two muscle receptors

Answer 10

Muscle spindles

GTOs

Question 11

How are muscle spindles arranged

Answer 11

in parallel with muscle fibers

Question 12

How are GTOs arranged

Answer 12

in series with muscle fibers

Question 13

What do muscle spindles monitor

Answer 13

information about joint position

Question 14

What do GTOs monitor

Answer 14

force produced by muscles

Question 15

Muscle spindle structure

Answer 15

Intrafusal fibers (contractile and non-contractile, bag/chain fibers, dynamic and static responses)

Question 16

Motor axons (efferent) of muscle spindle structure

Answer 16

• gamma fibers
• aka fusimotor system
• regulate activity of muscle spindle

Question 17

Does motor axon maintain or increase sensitivity of spindle?

Answer 17

Yes both

Question 18

Static gamma motor axon innervates

Answer 18

Static nuclear bag fiber and nuclear chain fibers

Question 19

Dynamic gamma motor axon innervates

Answer 19

Dynamic nuclear bag fiber

Question 20

Golgi Tendon Organ exists at what junction

Answer 20

musculotendinous junction

Question 21

How does GTO sense tension

Answer 21

“pull” on collagen fibers (due to muscle contraction or lengthening) leads to afferent fiber discharge

Question 22

What increases afferent firing of spindle

Answer 22

stretch muscle

“loading” of spindle

Question 23

What decreases afferent firing of spindle

Answer 23

contract muscle

“unloading” of spindle

Question 24

What is primary ending

Answer 24

Ia, dynamic

Question 25

What is secondary ending

Answer 25

II, static

Question 26

Are Ia spindles sensitive to rate of change in muscle length

Answer 26

Yes

Question 27

What do Ia afferents code

Answer 27

muscle length and velocity of muscle stretch

Question 28

Extension(mm) versus Discharge rate(spikes/sec)

Answer 28

positive relationship, both primary and secondary

Question 29

What does dynamic response of Ia spindles mean

Answer 29

increase in firing related to speed at which muscle is being stretched steady state firing after stretch has occurred reflects "new" muscle length

Question 30

Does group II only code for muscle length

Answer 30

yes

Question 31

Does fusimotor system maintain muscle spindle sensitivity?

Answer 31

yes

Question 32

How does fusimotor increase muscle spindle sensitivity

Answer 32

gamma efferent innervation increases spindle firing when muscle contracts (shortens) and spindles become unloaded, and also when stretched

Question 33

alpha-gamma coactivation

Answer 33

both alpha and gamma motorneurons maintain muscle spindle sensitivity during muscle shortening effectiveness dependent upon speed of muscular contraction typically occurs whenever movement is generated

Question 34

when does uncoupling happen

Answer 34

when CNS rely more on lengthening muscle to provide feedback independent control of alpha and gamma efferent (cat pic) set at different levels for different behavior

Question 35

Example of deafferentation studies

Answer 35

sensory neuropathies

Question 36

How does exercise affect proprioception

Answer 36

disturbed by exercise | related to fatigue, muscle soreness (pain)

Question 37

Specific false position sense by exercise

Answer 37

knee exercise: perceived to be more flexed | elbow exercise: perceived to be more extended

Question 38

Changes in proprioception following eccentric exercise

Answer 38

position sense force sense movement detection thresholds