A flexor muscle.
Flexor
The flex
The flexor is a muscle that bends part of your body.
Extender
A muscle that is an elevator raises or lifts a part.
The muscle in the thigh is called a quadriceps. It is a body part.
knee
An extensor straightens part of your body.
quadricep
A muscle called the Diaphragm
A muscle which bends or flexes any part; as, the flexors of the arm or the hand; -- opposed to extensor.
The point at which a muscle is anchored to an immovable part of the body, such as a bone, is called the origin. The origin serves as a stable attachment point, allowing the muscle to exert force when it contracts. In contrast, the other end of the muscle, where it attaches to a movable part, is known as the insertion.