sliding filament theory

Question 1

1 step of the sliding filament theory

Answer 1

A neurochemical stimulation, causes calcium ions to be released from the sarcoplasmic reticulum into the sarcomere prompting a reaction in each muscle fibre between the myosin and actin filaments.

Question 2

2 step in the sliding filament theory

Answer 2

Myosin filaments contain cross bridges (myosin heads) at regular intervals. These cross bridges attach and reattach at different times along the actin pulling on them to create movement and maintain tension. The breakdown of ATP releases energy to stimulate cross bridges.

Question 3

3 step in the sliding filament theory

Answer 3

This causes the actin to move into the centre of the sarcomere, shortening the myofibril and causing the actin and myosin filaments to be almost fully overlapped when in a fully contracted position

Question 4

4 step of the sliding filament theory

Answer 4

As each sarcomere shortens so does the total length of each muscle fibre

Question 5

5 step in the sliding filament theory

Answer 5

When the contraction finishes, the myosin and actin filaments return to a relaxed position. ATP releases energy causing myosin to detach from the actin and the cross bridge is broken.

Question 6

what are the two acronyms

Answer 6

HAIZ and ZBBL

Question 7

what is the H zone

Answer 7

distance between the actin filaments

Question 8

what is the A band

Answer 8

length of the myosin filament

Question 9

what is the I band

Answer 9

distance from the edge of the myosin to the z-line

Question 10

what is the Z line

Answer 10

edge of the sarcomere