Muscular System Functions Voluntary movement Forms some sphincters

Muscular System • Functions • Voluntary movement • Forms some sphincters • Protection of some organs • Stabilization of some joints • Posture • Heat production

Muscular System • Organs – Muscles

Muscular System • Organs – Muscles (includes tendons and aponeuroses)

• Structure of Skeletal Muscles – Muscle fibers

• Structure of Skeletal Muscles – Muscle fibers

• Structure of Skeletal Muscles – Muscle fibers • Contractile units within:

• Structure of Skeletal Muscles – Muscle fibers • Contractile units within: – Sarcomeres

• Structure of Skeletal Muscles – Muscle fibers • Contractile units within: – Sarcomeres

• Structure of Skeletal Muscles – Muscle fibers • Contractile units within: – Sarcomeres linked end-to end

• Structure of Skeletal Muscles – Muscle fibers • Contractile units within: – Sarcomeres linked end-to end; form myofibrils

• Muscle fibers bundled into fascicles

• Muscle fibers bundled into fascicles • Fascicles bundled to form the muscle

• Connective Tissue in Muscle

• Connective Tissue in Muscle – Endomysium

• Connective Tissue in Muscle – Endomysium – Perimysium

• Connective Tissue in Muscle – Endomysium – Perimysium – Epimysium

• How Muscles Create Movement at Joints – Muscles must cross joints – Insertion pulled towards origin

Fascicle Organization • Parallel – Greatest range of motion

Fascicle Organization • Parallel • Pennate

Fascicle Organization • Parallel • Pennate – Strongest force of contraction

Fascicle Organization • Parallel • Pennate • Convergent

• Fascicle Organization • Parallel • Pennate • Convergent – Greatest versatility

• Fascicle Organization • Parallel • Pennate • Convergent • Circular

Muscle-Bone Lever Systems

Muscle-Bone Lever Systems F

Muscle-Bone Lever Systems F

Muscle-Bone Lever Systems R F

Muscle-Bone Lever Systems E R F Third-class lever

Muscle-Bone Lever Systems E R F Third-class lever

E R F Third-class lever

E R F Third-class lever

E R F Third-class lever

Amplifies speed and distance at the expense of force E R F Third-class lever

Muscle-Bone Lever Systems E R F Third-class lever

Muscle-Bone Lever Systems E R F Third-class lever

Muscle-Bone Lever Systems E R F Third-class lever

Muscle-Bone Lever Systems E R F Second-class lever

Muscle-Bone Lever Systems E R F First-class lever

Muscle Interaction • Prime Mover – Muscle most responsible for an action • e. g. : abduction of arm: deltoid

Muscle Interaction • Synergistic muscles – Assists prime mover • e. g. : supraspinatus assists deltoid in abduction

Muscle Interaction • Fixator muscles – Holds bone of origin steady • e. g. : serratus anterior holds deltoid’s bone of origin steady during abduction

Muscle Interaction • Antagonistic muscles – Action opposite that of the prime mover • e. g. : lats and pects adduct • must not contract during abduction

• Muscle names may indicate the direction of the muscle fibers (e. g. , transversus abdominis, external oblique).

• Muscle names may indicate the direction of the muscle fibers (e. g. , transversus abdominis, external oblique). • A muscle may be named according to its location (e. g. , temporalis, tibialis anterior).

• The size of the muscle may be indicated in the name (e. g. , gluteus maximus, adductor Iongus).

• Some muscles are named on the basis of shape (e. g. , deltoid, serratus anterior). • Muscles may be named after their origin and insertion (e. g. , sternocleidomastoid).

• A muscle may be named according to its location (e. g. , temporalis, tibialis anterior). • Muscles may be named for their number of origins (e. g. , triceps brachii, quadriceps femoris).

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