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.

Muscle Contraction

Muscle contractions during exercise can be divided into three categories; isotonic (meaning same tension throughout the contraction), isometric (meaning same tension), also known as a static contraction and isokinetic muscle contractions which are performed with a constant speed throughout the movement. Here we explain these in more detail including in which types of exercise they occur.

Muscle Fibre Types

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.

Types of Muscle

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

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

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.

Nerve Propogation

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).

What are the different shapes of muscle? There are a number of different muscle shapes within the human body including circular, convergent, parallel, pennate and fusiform. Here we explain where they are found in the body and what their function or purpose is.

More Human Muscles: