Changes

: [[Muscle]]s are made of [[Muscle Tissue|muscle tissue]].: The [[Muscle Cell|cells]] in the [[muscle]]s have a special part called 'muscle fibres' which can make the [[Cell (Biology)|cells]] shorter or longer.: When a [[muscle]] gets shorter it has [[contract]]ed and when a muscle gets longer it has relaxed.: Most muscles [[muscle]]s come in [[antagonistic]] pairs. This means when one contracts [[contract]]s the other must relax.