The celebrated jumping frog of Mark Twain's Calaveras County, California would not have been so famous (nor would Mr. Twain) without striated muscles. Striated muscles typical of the rear leg skeletal muscles enable frogs to leap long distances. Composed of narrow and wide elongated fibers, striated muscles appear striped when observed under a microscope.

View a second image of frog striated muscle.

Frogs depend on three types of muscle: smooth, cardiac, and striated. The striated, or skeletal, muscles are bundled together in cords and connect to bones via tendons. Striated muscle cells are among the largest cells in the body of a vertebrate. A favorite of commercial slide preparers, frog striated muscle allows the histology student to view and study the transverse striations, nucleus, collagen tissue, endothelium, and tough surrounding epimysium typical of vertebrate skeletal muscle cells. Physiologists and biophysicists employ frog striated muscle cells as working models for explaining the sliding filament theory and for assessing the mechanical forces and velocities involved with leg (or other skeletal) movement. Lab dissections of the exposed femur, the knee, and the gastrocnemius muscle with attached Achilles tendon allow the researcher to measure response when electrical shocks are applied to contract the muscle.