Muscles; Myosin and Actin

Muscles are needed for you to live, engage with the world and in respond to it. Despite this all of the most fundamental aspects of life rely on a relatively simple yet complex mechanism.

That is your muscles fundamentally rely on just 2 structures to work. Myosin and actin. Together these 2 units make your muscle contract and when disengaged relax.

Although the mechanism itself is simple ensuring it works reliably, is controllable and fine tuned is not so simple. This is where myosin and actin become more complicated.

Without fine control you would never be able to ensure that you can pick up a pen or egg. The strength used would break anything not strong enough o resist your full grip strength. At the same time your heat would contract with full force all the time. The problems would be wide ranging and serious.

In fact we can observe this exact phenomena when some dies. Rigor mortis shows you what happens when the body can not control muscle contractions.

The process of a muscle contracting is a good example of how the human body uses active transport to shuttle the right things to the right places at the right time. Then how it recovers that same material to recycle and reuse.

Further to make these changes in chemical position happen another layer of regulation exists. Not quite turtles all the way down but enough that muscles can not just contract randomly. A lay of control is needed to ensure the seemingly simple mechanism works as and when intended.

Of course nothing can work without the nervous system. That is because the nerves send a signal to initiate the whole process of a muscle contracting. Without this nothing happens.

Relevant links:

Myosin Structures in Muscle
https://bio.libretexts.org/Courses/Ouachita_Baptist_University/Reyna_Cell_Biology/07%3A_(T3)_Cytoskeleton/7.07%3A_Actin_-_Myosin_Structures_in_Muscle

Actin, Myosin, and Cell Movement
https://www.ncbi.nlm.nih.gov/books/NBK9961/