Muscular System

The contractile unit of muscle tissue

Sarcomere

The lateral boundary of the sarcomere where the myofilament actin attaches

Z line

The cytoplasm of a muscle fiber (unique to muscle cells)

Sarcoplasm

The stored form of glucose found in the liver and muscles

Glycogen

Parallel filaments that form muscle

Myofibrils

The filaments of myofibrils composed of actin and myosin

Myofilaments

The thin filaments of muscle myofilaments, where myosin binds to generate muscle contraction

Actin

The thick filaments of myofilaments with a fibrous head, neck, and tail that bind to actin

Myosin

The connective tissue covering each muscle fiber

Endomysium

Fibrous elastic tissue that surrounds a muscle

Epimysium

Bundles of muscle fibers; the singular is “fascicle”

Fasciculi

The connective tissue that covers a bundle of muscle fibers

Perimysium

A strong fibrous connective tissue that attaches muscle to bone

Tendon

A dense layer of vascular connective tissue enveloping the bones except at the surfaces of the joints

Periosteum