Muscle Contraction
Updated: 5/18/2020
Muscle Contraction

Storyboard Text

  • Hi! I'm Professor Wyatt from the university in the city center. I would like to explain to you how muscle contraction works.
  • Wow, that sounds really cool. Go ahead!
  • First I'll tell you why an antagonistic muscle pair is needed for contraction. What happens is when one muscle contracts, the other relaxes and visa versa.
  • Interesting. Do you have an example?
  • Sure! One of the most common examples is a grasshopper leg. As the leg extends, the extensor muscle contracts while the flexor muscle relaxes. The opposite happens when the leg flexes.
  • That makes so much more sense now! What else do I need to know?
  • Well, you should know that in order to connect all the bones and muscles in the body to allow for movement, there are two special types of tissues. Tendons connect the muscles to the bones, and ligaments connect the bones to each other.
  • I'll remember that! What else?
  • I want to know more! What do they do?
  • The muscles in you body are comprised pf myofibrils that are responsible for muscle movement and contraction. The two most important terms to know for this aspect are myosin and actin.
  • Well, the myosin heads use ATP as a source of energy to be able to bind to actin strands and pull themselves across the actin. This process repeats whenever a new molecule of ATP attaches to the myosin heads, and this process results in the contraction of a muscle.
  • Wow! I learned a lot of really interesting things today! Thanks for my free lesson!