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serves as a pump, propelling blood through blood vessels to all body tissues

striated, it is uninucleate and under involuntary control.

cushioned by small amounts of endomysium and are arranged in spiral or figure 8–shaped bundles

contractile unit
contains actin and myosin

protein fibers that form attachment site for actin

center of sarcomere
contains only myosin

contains only actin

where actin and myosin overlap

where myosin are anchored

thin myofilament
- resemble 2 strands of pearls

thick myofilament
- resemble golf clubs

attachment site on actin for Ca2+

- filament on grooves of actin
- attachment site on actin for myosin

thread-like proteins that make up muscle fibers

contractile unit
- contains actin and myosin

proteins that make up myofibrils
- Ex. actin and myosin

cytoplasm of muscle fiber (cell)

cell membrane in muscle fibers
- contains T-tubules

wrap around sarcomeres at A band
- associated with sarcoplasmic reticulum

type of SER
- surrounds myosin
- stores and releases Ca2+