Effectors – Muscle Contraction
Skeletal Muscle is made up of Long Muscle Fibres
Muscles are stimulated to contract by neurones and act as effectors.
- Skeletal muscle (also called striated, striped or voluntary muscle) is the type of muscle you use to move e.g. the biceps and triceps move the lower arm.
- Skeletal muscle is made up of large bundles of long cells, called muscle fibres.
- The cell membrane of muscle fibre cells is called the sarcolemma.
- Bits of the sarcolemma fold inwards across the muscle fibre and stick into the sarcoplasm (a muscle cell’s cytoplasm). These folds are called transverse (T) tubules and they help to spread electrical impulses throughout the sarcoplasm so they reach all parts of the muscle fibre.
- A network of internal membranes called the sarcoplasmic reticulum runs through the sarcoplasm. The sarcoplasmic reticulum stores and releases calcium ions that are needed for muscle contraction.
- Muscle fibres have…