Posture/Motor Control

Question 1

Sign
symptom
syndrome?

Answer 1

Sign - observable

symptoms: reported by patient
syndrome: clusters of signs/symptoms

Question 2

what two brain areas help to refine movement initiated by motor cortex?

Answer 2

Basal Ganglia

Cerebellum

Question 3

what is a motor unit?

Answer 3

the group of muscle fibers that are innervated by a single alpha motor neuron

Question 4

muscle strength grows how neuronally?

Answer 4

incrementally, changes depending on how many impulses are sent

Question 5

What is Henneman’s size principle?

Answer 5

start recruiting small fatigue resistant motor neurons then larger fatiguable ones as you need more force

Question 6

what is meant by a ‘secure’ motoneuron?

Answer 6

an impulse will definitely release ACh(NicR) and make it contract.

Question 7

What is a fibrillation?

Answer 7

tiny contraction of single muscle cell

Question 8

what is fasciculation?

Answer 8

groups of muscle fibres contracting involuntarily. usu from degen MN

Question 9

what happens to muscle after long term denervation?

Answer 9

atrophy (Cushing’s)

Question 10

are muscles inactive? when are they?

Answer 10

usually not: resting tone

only during REM sleep

Question 11

What encodes length of muscle fibres?

Answer 11

intrafusal muscle fibers

Question 12

what encodes force in muscle?

Answer 12

golgi tendon organ

Question 13

golgi tendon organ encodes?

Answer 13

muscle force

Question 14

intrafusal muscle fibres encode?

Answer 14

muscle length

Question 15

how to record muscle activity?

Answer 15

Electromyography (EMG)

Question 16

2 things come into play when catching a ball dropped from a height:

Answer 16

1. feedforward (anticipation)

2. feedback (adjustments)

Question 17

LMN lesion:

Answer 17

flaccid paralysis
hyporeflexia
decreased tone
fascicullations/fibrillations
atrophy

Question 18

anything between cotricospinal tract and alpha motor neuron?

Answer 18

usually local interneurons

Question 19

spinal cord gray matter, what is medial? what is laterl?

Answer 19

proximal muscles

distal muscles

Question 20

what happens in the brainstem with the corticospinal tract?

Answer 20

collaterals to reticular formation

Question 21

what does the lateral and medial vestibulospinal tracts do?

Answer 21

postural maintenance

Question 22

what does reticulospinal tract do?

Answer 22

midline muscles/posture

Question 23

what does colliculospinal tract do?

Answer 23

helps with orienting reflex of sight

Question 24

UMN lesion?

Answer 24

spastic paralysis/weakness
increased tone
hyperreflexive
clonus
\+ve babinski

Question 25

pattern generators are usually located where?

Answer 25

all in the spinal cord, eg. stepping reflex/gait cycle

Question 26

what happens to decerebrate cat gait when treadmill speed increased?

Answer 26

sensory feedback of muscle length to spinal cord allows speed to increase

Question 27

ataxic gait affected where?

Answer 27

cerebellum, coordination

Question 28

choreaform gait

Answer 28

excessive movements

Question 29

Which pathways for:

1. Voluntary movements
2. stability/posture?

Answer 29

1. lateral descending

2. medial descending

Question 30

Decerebrate posture?

Answer 30

extended upper and lower limbs, arched back

Question 31

decorticate posture?

Answer 31

flexed upper limbs, extended lower limb

Question 32

lesion above red nucleus you get?

Answer 32

decorticate

Question 33

below red nucleus you get?

Answer 33

decerebrate

Question 34

intact rubrospinal tract from red nucleus causes what?

Answer 34

upper limb flexors: decorticate

Question 35

how can you tell is UMN or LMN in facial nerve?

Answer 35

UMN, superior facial muscles are preserved due to dual innervation