Beauty Care Anatomy and Physiology

Structure of the Muscular System
The Muscular System has three kinds of muscle tissue, Cardiac, Smooth and Skeletal. They are all similar in ways but different in others. Cardiac and Skeletal muscle cells are both striated which means the actin and myosin filaments which facilitate muscle contractions are laid out in the same striped pattern yet cardiac muscle is involuntary muscle like smooth muscle   while skeletal is voluntary muscle.
Smooth muscle creates the movement required for the blood vessels to constrict and dilate, the pupil of the eye to dilate and it is found in the walls of all the hollow organs allowing them to move whatever substance needs to move to function properly like food through the stomach and intestines. Smooth muscle tissue is made up of almond shaped cells with a single nucleus (uninucleated) and as they are nonstriated the actin and myosin fibres are found at the cells edges in the plasma membrane. Each cell can contract on it’s own or co-ordinate with surrounding cells to move the food, blood, urine etc to where it should be. This type of muscle movement is involuntary as the conscious part of the brain does not control it, just the nervous system and hormones. Smooth muscle cells are unique in that they can divide so uninjured cells can regenerate injured tissue.
Cardiac muscle is made of small cells known as cardiocytes which are only found in the heart. Usually a cardiocyte has one central nucleus (although there can be up to 5) and a cylindrical, striated, branched arrangement as it is interconnected with the surrounding fibres allowing it to send each contraction to the specific area of the heart when required. The cardiac muscle tissue contracts automatically with no conscious action from the person and is known as striated involuntary muscle for this reason. Special cells within the heart muscle tissue are known as pacemaker cells or sinoatrial nodes and they work alongside the nervous system depending on adrenalin levels...