Muscles Theory

Learn how muscles work including sliding filament theory, muscles actions, muscle fibre types, types of muscle contraction, the structure of a muscle fibre and types of muscle tissue found in the human body.

Although skeletal muscle cells come in different shapes and sizes the main structure of a skeletal muscle cell remains the same. If you were to take one whole muscle and cut through it, you would find the muscle is covered in a layer of connective muscle tissue known as the Epimysium.

The sliding filament theory is the method by which muscles are thought to contract. It is recommended that you read the muscle structure page before continuing with the sliding filament theory.

The diagram is a common one used to explain sliding filament theory but dont worry about trying to understand it all just yet.

Within skeletal muscle there are three types of fiber. Type one (I), type two A (IIa) and type two B (IIb). Each fiber types has different qualities in the way they perform and how quickly they fatigue.

What are the different shapes of muscle? There are 5 different muscle shapes within the human body:

  • Circular
  • Convergent
  • Parallel
  • Pennate
  • Fusiform

Muscle Contractions can be divided into:

  • Isotonic (meaning same tension)
  • Isometric (meaning same distance or not moving)
  • Isokinetic (meaning same speed)

There are three types of muscle found in the human body:

  • Skeletal Muscle
  • Smooth Muscle
  • Cardiac Muscle (heart muscle)

Nerve propagation is the way in which a nerve transmits an electrical impulse. In order to understand this, it is important to understand the structure of a motor neurone (nerve).

More Human Muscles: