19-muscle microanatomy

Understand the structural organization of muscle from the whole organ to myofilaments.

Muscles Fascicle Fiber (cell) Myofibril Myofilaments Make up myofibril Thick and thin regions

Know the terms for special organelles in muscle and understand their role in muscle contraction.

Myofilaments Actin (thin) Myosin (thick) In between thick filaments there is a thin filament (blue) Anchored together by Z disc (vertical lines) Z disc Vertical line that anchors thin filaments Solid platform Thick filaments pull thin filaments together→ brings z disc together→ shortens length of sarcomere/muscles shorten

Understand the function of an antagonist muscle and why it is important.

It is two sets of muscles that have different actions about a joint Need antagonistic muscles in order to stretch the muscle out and make it longer

Know the structural organization of the connective tissue sheaths associated with skeletal muscle.

Layers of CT that wraps around organ and penetrates it Epimysium Connective tissue sitting directly on top of the muscle and wraps around the muscle Good at resisting force Perimysium Goes around the fascicle Endomysium Ct sheath within fascicle Sits directly on the muscle fiber On top of plasma membrane

Know the functions of muscle and how they apply to your daily life.

Movement Standing still Maintain posture Rotator cuffs-muscle contracts Both contract-make joint incredibly stable Joint Stability