ap exam muscles

Epimysium

Surrounds the entire muscle.

Perimysium

Surrounds bundles of muscle fibers called fascicles.

Endomysium

Surrounds each individual muscle fiber.

DirecT

Muscle connects directly to bone (no tendon

Indirect

Muscle connects to bone through a tendon.

SarcolemmA

Muscle cell membrane.

Sarcoplasm

Cytoplasm of a muscle fiber; contains organelles.

Sarcoplasmic Reticulum

Stores and releases calcium for contraction.

Carries action potential deep into the muscle fiber.

Transverse Tubule Or T TUBULES

Myosin

Thick filament; pulls actin for contraction..

Actin

Thin filament; slides past myosin during contraction.

Troponin

Binds calcium to move tropomyosin.

Tropomyosin

Blocks actin binding sites when muscle is relaxed.

A Band contains….

Thick filaments

I Band Contains

Thin filaments