(S1W2) Control of Muscle Activation part 9

Question 1

What are Ia interneurons?

Answer 1

• an intermediate in between Ia afferent neurons and alpha ⍺ motoneurons
• they allow the muscle spindle to inhibit the opposite muscle that is contracting and causing the stretch

Question 2

Explain what Ia interneurons do using an example

Answer 2

• elbow flexing rapidly, muscle spindle detects triceps lengthening
• signal travels from muscle spindle, along Ia afferent neuron then via the Ia interneuron to alpha ⍺ motoneuron which inhibits the biceps

Question 3

What does oligosynaptic reflex mean?

Answer 3

• multiple synapses

Question 4

What is it called when opposite muscles inhibit each other?

Answer 4

reciprocal inhibition

Question 5

What does heterogenic mean?

Answer 5

one muscle having an effect on another muscle

Question 6

Is it possible for the muscle spindles in the triceps to stimulate the triceps and inhibit the biceps at the same time?

Answer 6

yes and this would achieve a bigger effect than either of those in isolation

Question 7

Why is the complexity of reciprocal inhibition good?

Answer 7

the complexity actually keeps things simple because it means one stimulus detected has two effects