Ch 10 The Muscular System 2

Definition of origin

(Or head) A muscle end attached to more stationary of two bones

Definition of insertion

Muscle end attached to bone with greatest movement

Definition of agonist

Muscle that, when it contracts, causes an action

Definition of antagonist

A muscle working in opposition to agonist

Definition of synergist

Muscles that work together to cause a movement

Definition of fixator

Stabilize joint/s crossed by the prime mover; prevent movement of the origin of the prime mover

Definition of prime mover

Plays major role in accomplishing movement

Explain how fasciculus orientation determines muscle shape and list examples of muscles that demonstrate each shape

🚨

Recognize muscle names based on specific nomenclature rules

?🚨

•Location: pectoralis gluteus, brachial.

•Size: maximus, minimus, longus, brevis.

•Shape: deltoid, quadratus, teres.

•Orientation of fascicles: rectus, oblique.

•Origin and insertion: sternocleidomastoid, brachioradialis.

•Number of heads: biceps, triceps.

•Function: extensor, abductor, adductor, masseter

Three classes of levers in the body

—Class I:  “Seesaw”

•Fulcrum between force and weight.

•Head movement at the atlantooccipital joint.

—Class II: “Wheelbarrow”

•Weight is between fulcrum and pull.

•Standing on toes; metatarsophalangeal joint.

—Class III: “Shoveling”

•Pull located between fulcrum and weight.

•Most common: biceps brachii with elbow as fulcrum

Example of