muscles & filaments

portion of the myofibril

runs from z line to z line

dark band that has thick filaments and thin filaments

portion of A band that contain only thick filament

during muscle contraction what happens to the h zone

central portion of a thick filament which is connected by proteins

contains z line and thin filaments

zig-zag shaped line is a membrand where the thin filaments are attached

these are long proteins made either of action or myosin

possess heads which are crucial for muscle contraction

covers active site on actin and prevents actin and myosin heads from interacting.

tropomyosin is connected to

for muscle contraction to occur:

What binds troponin and allows change in shape so that myosin heads can attach to the thin filaments.

these heads are made of proteins which attach to a particular portion of the thin filaments during muscle contraction

When the myosin heads attach to the thin filaments they are then called

anchored to the z line

what is the role of the myosin heads

organelle is wrapped around the myofibril like a lacey sleeve

for muscle contraction to begin

What reabsorbs calium ions after muscle contraction to help the muscle relax

plasma membrane of the muscle cell

long filamentous organelle found in muscle cells; band appearance

in order for the entire muscle cell to contract at the same time-

at the end of each muscle, the collagen fibers of the endomysium and perimysium come together to for either a ______ or________

both connect skeletal muscles to bone

connect muscle to muscle

this layer is connected to the fascia

contains collagen and elastic fibers, nerves and blood vessels

(cytoplasm) of the muscle cell

muscle's ability to react to a stimulus

muscle shortens upon stimulation

muscle returns to normal length after stretching.