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Muscles produce movement by pulling bones in different directions, depending on the type of joint. Muscles work singly or in groups on joints to produce movement.
There are 3 types of muscle tissue:
- Cardiac muscle is a specialised type of muscle found only in the heart. It relaxes and contracts continuously as the heart pumps blood around the body. Contraction of cardiac muscle is controlled by a pacemaker system within the heart – we cannot control heart rate consciously.
- Smooth muscle lies internally and makes up the walls of several soft organs in the body such as the bladder, the blood vessels and the intestines. These muscles are often called involuntary as they are not under conscious control – they work on their own.
- Skeletal muscle makes up the shape of the body and is used primarily for movement of the skeleton. This muscle is attached to bone and is often referred to as voluntary because it can be under conscious control. Because of the way it looks, it is sometimes known as striated (striped) muscle.