Lec slides 7

Question 1

how tell diff between bag and chain fibres

Answer 1

• bag have nuclei arranged squished in middle
• Chain have nuclei lined up in sequence

Question 2

Which of these are static vs dynamic: Bag1, bag2, chain

what does that mean

Answer 2

bag1 - dynamic

bag2 - static

Chain - static

Dynamic - more sensitive to changes in mbmnt and velocity

Static - more sensitive to absolute amount of stretch

Question 3

how do muscle spindles activate?

Answer 3

1. Spindle stretches
2. intrafusal muscle fibres stretch
3. sensory endings attached to the intrafusal musc fibres open
4. allow ions to flow in (graded potential)

Question 4

Rapidly adapting and slow adapting receptors provide what type of info

Answer 4

rapid - dynamic info of stim

Slow - static info of stim

because the rapid would get used to sensation and stop sensing it

Question 5

Bag and chain fibres are intrafusal or extrafusal?

Answer 5

intra - because they are giving sensory feedback from inside the body