List 3 ways muscle action may be determined.

The muscle action can be determined by:

* Prime Movers and antagonist: Prime movers are also called the agonist, it is the muscle that provides the force that drives the action. Regarding to the antagonist muscle, it is the opposite to a prime mover as it provides resistance or reverse in a given movement. They are paired up on opposite sides of a joint.

* Synergists: There are one (or more) synergists involved in an action, the are muscles that help the prime mover when it is playing its role.

* Stabilizers: Their fuction is to keep bones immobile when it is needed. For example, the muscle of your back, they are stabilizers when the keep your posture sturdy.

≅200-130 milions years ago pangea splited in 2 continents