The Muscular System

A muscle is made up of many muscle tissues that are bundled together. These muscle tissues are made up of different muscle cells, which have a lot of mitochondria.

Mitochondria produce energy through respiration, which allows the muscle to contract and move. The large number of mitochondria in muscle cells allows them to generate the energy required for movement.

The skeleton is covered by muscles, attached to the bones with strong tendons. It is important to remember that muscles work by contracting. They get shorter, pulling the bone if it is a part of the joint, and this moves the bone.

Antagonistic pairs

Muscles work together in pairs at a joint to allow movement, which we call antagonistic pairs. One muscle in the pair contracts while the other relaxes. For example, at the elbow joint:

  • To bend the arm, The bicep contracts and shortens while the tricep relaxes and elongates.
  • To straighten the arm – The tricep contracts and shortens while the biceps relaxes and elongates

Muscles are only capable of pulling, not pushing. The muscle pulls the bone when it contracts.