Skeletal Muscle Fibers (Three Types)

Fast Fibers

Fast Glycolytic

Intermediate Fibers

Fast Oxidative Glycolytic

Slow fibers

RED muscle fiber (high in myoglobin content and has many mitochondria).

Slow Fibers

Slow Oxidative

Slow fibers

Slow contraction rate.

Slow fibers

Smallest diameter,so least powerful.

Intermediate fibers

WHITE muscle fiber, myoglobin content.

Fast fibers

WHITE muscle fiber.

Skeletal Muscle Fiber

is either "slow" or "fast" depending on how fast ATP is hydrolyzed in the myosin heads

Fast fibers

largest diameter, so strongest.

Fast fibers

Fast contraction rate too.

Intermediate fibers

Fast contraction rate.

Fast fibers

Few Mitochondria.

Slow fibers

High fatigue resistance

Intermediate fibers

Intermediate fatigue resistance. Intermediate number of mitochondria.

Slow fibers

Located in the: -Neck Muscles -Back Muscles -Calf Muscles

Fast fibers

Located in the: -arm muscles

Intermediate fibers

Located in the: -leg muscles (running/walking)

Fast Fibers

Low fatigue resistance.

Intermediate fibers

Mid-size fiber diameter