Types of Muscle Fibers uni 6

Sources of energy

Stored ATP

ATP present in muscle fibers

5-6 sec

Aerobic cellular respiration

Requires glucose and O₂

Slow

But very efficient

Glycolysis

Doesn’t require oxygen

Aerobic cellular respiration

Types of contraction

Power, speed and duration

ATP source in muscle fibers

Red fibers and white fibers

red fibers?

White fibers in muscle fibers?

Types of muscle fibers

Slow oxidative fibers (SO)

Fast oxidative-glycolytic fibers (FOG)

Fast glycolytic fibers (FG)

Fast oxidative-glycolytic fibers (FOG)?

Fast glycolytic fibers (FG)?

Slow oxidative fibers (SO)?

Muscle tissue

Cardiac muscle

Functions to pump blood continuously

Contracts 10-15X longer than skeletal muscle to a single action potential

Stimulated by autorhythmic muscle fibers

Self-excitable

Not neurogenic

Smooth muscle

Motor unit in muscle tissue

Composed of a motor neuron and all of the muscle fibers it innervates

2 types of motor unit

Exercise-induced muscle damage

Aging

In part due to decreased levels of physical activity there is a slow, progressive loss of skeletal muscle mass

Replaced by fibrous connective tissue and adipose tissue

Can be avoided or slowed with weight bearing exercises

Continues to make proteins and maintains muscle