How can we help?
You can also find more resources in our
Select a category
Something is confusing
Something is broken
I have a suggestion
What is your email?
What is 1 + 3?
Long, have bundles of myofibrials
Part of muscle cells, made up of repetive units called sarcomeres
Make up myofibirals and are where contractions happen
Seperate each sarcomere
Thick myosin filaments (red)
Thin actin filaments (blue)
Space between actin filamints
Shorter, H zone becames smaller
The thick filiments (myosin) pull the thin filaments (actin) twards the H zone. When the pull occurs, the Z lines are pulled in and causes the s
arcomeres to shorten.
Muscle fibers shorten
When several hundred of these sarcomeres shorten