There are three types of muscle found in the body:

Cardiac muscle is only found in the heart, is striated in appearance and under involuntary (unconscious) control.

Smooth muscle makes up the walls of organs and blood vessels, is involuntarily controlled and appears without striations.

Skeletal muscle is attached to the skeleton to produce movement. It is striated in appearance and under voluntary control.

The functions of muscle in the body are to produce movement, maintain posture and shape, stabilise joints and generate heat. As well as this muscle has four main characteristics: excitability (it responds to stimuli), contractility (it can shorten forcefully), extensibility (it can stretch) and elasticity (it returns to its resting length after stretching).

Muscle Fibre Types

To help the body cope with a wide variety of physical demands several types of skeletal muscle fibres have evolved.

Slow Twitch and Fast Twitch muscle fibres are capable of producing either slow, continuous contractions over a long periods of time or very fast, powerful contractions for a few moments.

Physiologically these fibres are very different and their make-up gives them their different capabilities.