(S1W2) Control of Muscle Activation part 5

Question 1

What is reccurent inhibition? And what cells carry it out?

Answer 1

• just means the muscle inhibiting itself
• Renshaw cells

Question 2

Fill in the missing labels

Answer 2

left - ⍺ (alpha) motoneuron
rigth - Renshaw cell

Question 3

How does recurrent inhibition work?

Answer 3

• when a signal stimulates a muscle, it also stimulates the Renshaw cell within the nervous system
• the Renshaw cell then inhibits that muscle
• the amount of inhibition (amount of dialling down) can be controlled by the central nervous system
• our brain and nervous system can excite or inhibit this Renshaw, meaning we can control the muscle’s sensitivity to stimulation from action potentials

Question 4

Sprint start example of recurrent inhibition

Answer 4

• when in set position, you want a situation where with the slightest amount of stimulus, you can quickly switch on all your muscle fibres and ramp up from 0 to 100% as quickly as possible
• do this by dialling down the Renshaw cells when ready to go, so there’s less inhibition of your muscles so more sensitive to signal

Question 5

What is a motoneuron pool?

Answer 5

pool of all ⍺ (alpha) motoneurons for 1 muscle

Question 6

How many Renshaw cells per muscle?

Answer 6

• 1 Renshaw cell linked to a motorneuron pool, consisting of lots of ⍺ (alpha) motoneurons, so lots of motor units
• so 1 Renshaw cell can control sensitivity of an entire muscle