10 terms

Muscle Contraction

Muscle cells
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
A Bands
Thick myosin filaments (red)
I bands
Thin actin filaments (blue)
H zone
Space between actin filamints
Contracted sarcomere
Shorter, H zone becames smaller
Sarcomere shortens
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