Inspiration is due to the contraction of the diaphragm and external intercostal muscles.
Correct spelling being "sternocleidomastoid", it is a paired muscle in the superficial layers of the anterior portion of the neck. It acts to flex and rotate the head. It also acts as an accessory muscle of inspiration, along with the scalene muscles of the neck.
A muscle that acts as a helper to accomplish a particular movement is called a synergist. Synergists assist the primary muscle, known as the agonist, by stabilizing joints and facilitating smooth movement during actions. They play a crucial role in ensuring coordinated muscle function and can also help to fine-tune the movement.
A prime mover is the muscle that has the most influence in one direction on the joint it acts on. For example the prime mover in extension of the forearm is the triceps.
synergistic muscle
A musculotropic substance acts on muscle tissue. It specifically targets and affects smooth muscle cells, resulting in changes to muscle contraction and relaxation.
The Holy Bible was written from and about God's deeds and acts.
The trapezius muscle is a superficial muscle of the neck and upper back that acts at the shoulder. It is responsible for movements like shoulder shrugging, scapular elevation, depression, retraction, and rotation.
Effector
The masseter acts as the antagonist.
sphincter
Glute medius
The muscle cell protein that acts as an ATPase enzyme is myosin. Myosin is responsible for converting chemical energy from ATP into mechanical energy during muscle contraction.