Chapter8 Muscles Vocabulary

Connective tissue covering entire muscle

Connective tissue coverering bundles of 10 to 100 muscle fibers called fascicles

Connective tissue covering individual muscle fibers

A plasma membrane covering each muscle fiber

Network of fluid-filled membrane-enclosed tubules (similar to smooth endoplasmic reticulum) that stores calcium ions required for muscle contraction.

A reddish pigment similar to hemoglobin in blood. In addition to the characteristic color it lends to skeletal muscle, myoglobin stores oxygen until it is needed by mitochondria to generate ATP.

Cylindrical structures extending along the entire length of the muscle fiber consisting of two types of protein filaments called thin filaments and thick filaments which do not extend the entire length of a muscle fiber

Compartments formed as thick and thin filaments overlap in specific patterns, the basic functional units of striated muscle fibers

Zig-zagging zones of dense protein material, dividing the I band in hald and separating one sarcomere from the next

The entire length of the thick filaments within the sarcomere, it has a darker color

Section at the center of an A band in which there are only thick filaments

Section of only thin filaments either side of the A band. Extends across two sarcomeres and is divided in half by a Z disk. Lighter colored.

Protein composing the thick filaments. Myosin tails make up the shaft of the filaments, myosin heads attach to the thin filaments

Composed of primarily of actin with tropomyosin and troponin. Myosin heads on the thick filaments bind to actin when tropomyosin stops covering it.

Cytoplasm of a muscle fiber, contains many mitochondria that produce large amounts of ATP during muscle contraction