Sliding Filament Theory

Question 1

Sliding Filament Theory

Answer 1

1. A stimulation releases calcium from the sarcoplasmic reticulum into the sarcomere
2. This allows actin filaments to reveal a binding site for the myosin head to connect
3. Myosin head binds to the actin filaments which creates a cross bridge
4. Breakdown of ATP releases energy to stimulate the myosin cross bridges to pull the actin filaments towards the mid line of the sarcomere
5. This results in the shortening of the sarcomere as the actin and myosin filaments “slide over” each other which causes the z lines to come closer together and the H zone shortens
6. Shortening each sarcomere shortens the myofibril, resulting in the shortening of the muscle fibres and movement occurs
7. Cross bridges attach and re-attach at different times to create movement and maintain tension
8. This process keeps repeating if the neural impulse is present or the muscle relaxes if the neural impulse ends

Question 2

Sarcomere diagram 2

Answer 2

see onenote (functional anatomy)