Muscles

4. layer of connective tissue that closely surrounds a skeletal muscle
8. composed of thin actin filaments held by direct attachments to structures called Z lines, which appear in the center
11. is a molecule that has 3 protein subunits and are attached to actin
12. membraneous channels extend into the sarcoplasm as invagination's continuous with the sarcolemma
14. thin filaments of a muscle fiber
15. composed of thick myosin filaments overlapping thin actin filaments
16. any of the elongated contractile threads found in striated muscle cells
18. a muscle which is connected to the skeleton to form part of the mechanical system which moves the limbs and other parts of the body
19. each muscle fiber within a fascicle lies within a layer of connective tissue in the form of a thin covering called this

1. the synapse where a motor neuron axon and a skeletal muscle fiber meet
2. center of a sarcomere where myosin can bind
3. neurotransmitter that motor neurons use to control skeletal muscle contraction
5. thick filaments of a muscle fiber
6. corresponds to the endoplasmic reticulum of other cells
7. the fine transparent tubular sheath which envelops the fibers of skeletal muscles
9. layer of connective tissue that extends inward from the epimysium and separates the muscle tissue into small sections
10. a band or bundle of fibrous tissue in a human or animal body that has the ability to contract, producing movement in or maintaining the position of parts of the body
12. a flexible but inelastic cord of strong fibrous collagen tissue attaching a muscle to a bone
13. striated repeating pattern of units
17. neighboring parallel lines that define the sarcomere