Lecture 6: Motor Receptors

Question 1

___________ refers to the use of sensory information to prepare for movement.

Answer 1

feedforward

Question 2

________ refers to the use of sensory information during or after movement to make corrections to the ongoing movement or to future movements

Answer 2

Feedback

Question 3

Neural activity begins with a decision, made where?

Answer 3

the anterior part of the frontal lobe

Question 4

In the sequence of producing normal movements, after a decision is made what happens next?

Answer 4

Motor planning areas are activated

Question 5

Control circuits are activated after the motor planning areas in producing normal movements. What do the control circuits consist of, and what do they do?

Answer 5

Consist of: basal ganglia and cerebellum

Regulate the activity in the upper motor neuron tracts

Question 6

What do UMN tracts do?

Answer 6

deliver signals to spinal interneurons and LMN

Question 7

What do LMN do?

Answer 7

Deliver signals directly to skeletal muscles, eliciting contraction of muscle fibers

Question 8

UMN tracts are are classified as what type of tracts?

Answer 8

Postural/gross movement
fine movement
nonspecific

Question 9

Postural/Gross movement tracts control what?

Answer 9

Automatic skeletal muscle activity

Question 10

Fine movement tracts control what?

Answer 10

Fractionated movements of limbs and face

Question 11

Nonspecific UMNs facilitate what?

Answer 11

All motor neurons

Question 12

What are fractionated movements?

Answer 12

Independent contractions of single muscles

Question 13

In all regions of the CNS, _______ information adjusts ______ activity

Answer 13

sensory

motor

Question 14

What are the proteins involved in muscle contraction?

Answer 14

Actin, myosin, troponin, and tropomyosin

Question 15

Voluntary Movement:

Answer 15

the purposeful motor act formed by complex integrations of multiple levels of sensory and motor nervous systems

Question 16

activation of Golgi tendon organs ________ alpha motor neuron activity

Answer 16

inhibits

Question 17

The purpose of intrafusal fibers are ________ reception

Answer 17

sensory

Question 18

The purpose of extrafusal fibers are __________ reception

Answer 18

motor

Question 19

Muscle spindles are proprioceptors that detect what type of stimulus?

Answer 19

muscle stretch

Question 20

Golgi Tendon Organs are proprioceptors that detect what type of stimulus?

Answer 20

tendon stretch

Question 21

CNS uses information from the muscle spindles to sense ________ _________ of body segments in space

Answer 21

relative position

Question 22

Primary Sensory Endings in muscle spindles are what type of fibers? What do they respond to?

Answer 22

1a

changes in muscle length and steady state muscle length (phasic and tonic)

Question 23

Secondary Sensory Endings in muscle spindles are what type of fibers? What do they respond to?

Answer 23

II

changes in steady state muscle length (tonic)

Question 24

True or false: spindles don’t fire when muscles are relaxed

Answer 24

FALSE

Question 25

When a muscle is shortened, does the activity of muscle spindles increase or decrease (hypothetically with nothing else involved)?

Answer 25

Decreases

Question 26

What type of Gamma MN innervates dynamic nuclear bag fibers and increases the dynamic sensitivity of 1a fibers?

Answer 26

Dynamic Gamma MN | phasic and tonic

Question 27

What type of Gamma MN innervates both static nuclear bag fibers and chain fibers and decreases the dynamic sensitivity of 1a fibers?

Answer 27

Static Gamma MN | tonic

Question 28

Golgi tendon organs are Innervated by what type of sensory fibers?

Answer 28

1b

Question 29

Golgi tendon organs are sensitive to changes in _______ _______ (i.e. the stretch of the tendon)

Answer 29

muscle tension

Question 30

The afferent signal from the Golgi tendon organ ________ activity of the motor neuron and results in muscle relaxation via the negative feedback system

Answer 30

inhibits

Question 31

Golgi tendon organ negative feedback response prevents damage to the muscle caused by excessive ___________

Answer 31

contraction

Question 32

An alpha motor neuron and the muscle fibers it innervates is referred to as a:

Answer 32

motor unit

Question 33

_____ ______ ______ are cluster of motor neurons within the spinal cord that all innervate a single muscle

Answer 33

motor neuron pools

Question 34

Different types of Muscle fibers are innervated by _____ or _____ motor neurons

Answer 34

small | large

Question 35

Innervate slow twitch fibers generate less force than fast-twitch fibers maintain levels of forces for long periods postural control

Answer 35

Small MNs

Question 36

Innervate fast-twitch fibers produce larger forces but fatigue very quickly Generate fast muscular forces

Answer 36

Large MNs

Question 37

Areas where the motor axon ramifies into several fine branches

Answer 37

neuromuscular junction

Question 38

What is the "all or non" manner?

Answer 38

all of muscle fibers innervated by the same MN respond faithfully and synchronously to each action potential of the MN

Question 39

What MNs are recruited and fired first, larger or smaller?

Answer 39

Smaller

Question 40

What is the formula for Ohm's law?

Answer 40

V=IR | voltage = current X resistance

Question 41

Poliomyelitis is a disease of UMN or LMN?

Answer 41

LMN

Question 42

What is post-polio syndrome?

Answer 42

Due to the reason that overextended surviving neurons cannot support abnormal number of axonal branches, some distal branches die

Question 43

What are some side effects of post-polio syndrome?

Answer 43

muscle weakness joint and muscle pain fatigue breathing problems

Question 44

What are some positive signs for UMN lesions?

Answer 44

Babinski Test Hoffman's sign pronator drift

Question 45

What happens to Mass, Strength, DTR, and tone in and UMN lesion?

Answer 45

Mass- decreases slightly Strength- decreases (Spastic Paralysis) Tone- hypertonia DTR- hyper-reflexia

Question 46

What happens to Mass, Strength, DTR, and tone in and LMN lesion?

Answer 46

Mass- decreases dramatically Strength- decreases (Flaccid paralysis) Tone- hypotonia DTR- hypo-reflexia

Question 47

Fasciculation are really only normally seen with what type of lesions?

Answer 47

LMN lesions

Question 48

What are some examples of causes for UMN Lesions?

Answer 48

Stroke Demyelination MS

Question 49

What are some examples of causes for LMN Lesions?

Answer 49

Polio | Diabetic Neuropathy