1. Muscle Tissue Characteristics of Muscle
Responsiveness: to produce chemical signals coordinated with electrical charges
Conductivity: to pass stimulus beyond local area to excite contraction
Contractility: to shorten when stimulated
Extensibility: to stretch between contractions
Elasticity: to return to original shape

2. Skeletal Muscle
Skeletal muscle: voluntary striated muscle attached to one or more bones
Striations: caused by overlapping of contractile proteins

3. Myofilaments Myofilament: long protein cords, fills muscle cell
A myofibril is a bundle of 3 myofilaments
Myofilaments:
Thick filaments: made of myosin, looks like a golf club
Thin Filaments: are composed of two strands of proteins, F actin and G actin where G actin contains active sites where the head of myosin can bind
Elastic filaments: made of titin, flanks the thin filament and anchors it to the Z disk

4. Striations
A band (dArk band): consists of thick filaments that lay side by side
I band (L(I)ght band): consists of thin and elastic filaments between thick filaments
H band: a section of the A band that is not covered with thin and elastic filaments
Z disk: a dense protein that anchors thin and elastic filaments, central to contraction of muscle

5. Striations
Sarcomere: the functional contractile unit located between the Z disks