2. SKELETAL MUSCLE & NEURAL CONTROL OF MOVEMENT

Question 1

the spinal cord contain these 3 types of neurons:

Answer 1

1. motor neurons
2. sensory neurons
3. interneurons

Question 2

what are the 5 common features of the NMJ?

Answer 2

1. Schwann cells present
2. terminal contains ACh
3. basement membrane lines the synaptic space
4. post-synaptic membrane contains ACh receptors
5. connector microtubules at postsynaptic membrane transmit electrical signal deep within muscle fibre

Question 3

what is EPSP

Answer 3

ACh stimulates connecting neuron, Na+ diffuse into neuron, AP generates if threshold is reached

Question 4

what is IPSP

Answer 4

hyperpolarizes

the neuron, making it more difficult to fire

Question 5

what is the size principle?

Answer 5

with increased muscle force, motor neurons with larger axons are recruited

Question 6

what is the definition of fatigue?

Answer 6

decline in force capacity with repeated stimulation or during a given time period

Question 7

what are 4 components that impact voluntary muscle action

Answer 7

1. CNS
2. PNS
3. NMJ
4. muscle fiber

Question 8

how is force regulated?

Answer 8

1. frequency

2. recruitment

Question 9

how are motor signals regulated?

Answer 9

1. feedback through reflex loops at spinal cord

2. feedback or descending control from supraspinal centres

Question 10

what is the function of a muscle spindle?

Answer 10

able to detect, respond to, and modulate changes in length of the extrafusal fibers

Question 11

what are the 3 main components that make up the stretch reflex?

Answer 11

1. muscle spindle that responds to stretch
2. afferent nerve fiber caries sensory impulse from spindle to spinal cord
3. efferent spinal cord motor neuron that activates the stretched muscle fibers