Three Basic Types of Muscle (Smooth, Cardiac, Skeletal)

Knowledge of the physiological response of muscles to active exercise is needed to understand the nature and benefits of a regular exercise program. There are three basic types of muscle: smooth, cardiac, and skeletal.

Smooth muscle is found in the walls of the hollow organs (stomach, intestine, bladder) and in the linings of most blood vessels. It is controlled by the autonomic nervous system and cannot be willfully controlled. Although its action cannot be directly affected, regular exercise and proper nutrition greatly improve its efficiency.

Cardiac muscle fibers are involuntary in nature, but unlike smooth muscle, the heart responds almost immediately to the increased demands of exercise.

Skeletal muscle is under conscious control and therefore can be disciplined and developed through proper exercise. The Central Nervous System controls these muscles. There are more than 600 skeletal muscles in the body, of various sizes and shapes, attached to more than 200 bones. However, about 75 pairs of muscles are responsible for most human movements.

• Three muscle types: smooth, cardiac, skeletal.
• Smooth: hollow organs and blood-vessel linings; autonomic control; involuntary.
• Cardiac: involuntary, but responds almost immediately to exercise demands.
• Skeletal: voluntary, CNS-controlled; can be trained.

• 600 skeletal muscles, attached to >200 bones; ~75 pairs do most human movement.

• skeletal-muscle-structure — internal architecture of skeletal muscle.
• muscle-contraction-nature — voluntary control and the all-or-none law.
• muscle-action-roles — how skeletal muscles act as movers/stabilizers.