wgu s4: muscles

Movement types

  • Angular- any movement that changes an angle

    • Flexion & Extension… Hyperextension - muscle contracting or extending

    • Abduction(away from body) & Adduction(toward body)

    • Circumduction - a circular motion combining the main 4 previous

  • Rotational - moves in a circle around its axis

    • pronation - going forward/in … supination - going backward/out

SLIDING FILAMENT MODEL - the process of a muscle contracting

  • nerve signal reaches muscle fiber

    • releases acetylcholine at the neuromuscular junction.

      • This causes action potential to spread across the muscle cell membrane (sarcolemma) and travel through structures called T-tubules.

        • T-tubules triggers sarcoplasmic reticulum to release calcium ions (Ca²⁺)

          • Calcium binds to troponin,

            • tropomyosin move away from actin

              • Myosin binds to actin

Hydrolysis of ATP is the process of ATP turning into ADP

da Power stroke is da muscle filament moving towards center of sarcomere

Anaerobic metabolism - Produces energy quickly

Aerobic metabolism - Slow but steadier energy

Muscles - INSERTION moves to the muscle ORIGIN when contracting

  • STERNOCLEIDOMASTOID - the twisting neck muscle on the side below the ear

  • Semispinalis capitis - the long skinny back neck muscles, also part of back, help flex, extend, and rotate neck

  • ischiocavernosus muscle of the pelvis - the walls around the private parts

ARM mucles

  • supraspinatus - Abduction of arm

  • infraspinatus - lateral rotation

  • subscpolaris - internal rotation

Foot muscle

  • Fubularis longus - pulls foot up laterally, lateral to shin

  • fibularis brevis - like ^ but smaller

  • Tibialis anterior - push heel out, invert foot

LEG muscle

  • Rectus femoris - the center quad muscle

  • adductor MAGnus - the inner thigh hip adductor (magnus like MAGNUM cause its close to the dong)

SKELETAL MUSCLE TYPES

  • circular

  • Fusiform - shaped like a sesame seed

  • convergent - broad origin with a singular insertion point

  • parallel - straight up and down or across

  • pennate - wierd, feather like fiber pattern

Plantar groups - become more deeper the higher the numbers go

  • I - VI

Scalene muscles = neck

bicep femoris = hamstring