The bones in your body are connected by joints, which make it possible for you to move. Diseases of the joints, such as arthritis, can make movement difficult or painful. Smoking increases your chances of developing two diseases that affect the joints -- rheumatoid arthritis and lupus. While the muscular system is not directly affected by smoking, the function of the muscular system (specifically, movement) is affected by other conditions, such as arthritis and multiple sclerosis, that are made more likely by smoking.
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What does the muscular system do?
The primary function of the muscular system is to produce motion in the body. Because our bodies demand our muscles do different tasks, we have three types of muscles, each type with its own duty.
Cardiac muscle is found only in the heart and its job is to power the action that pumps blood through the body. Smooth muscles surround or are a part or our internal organs. Cardiac and smooth muscles are also referred to as "involuntary" muscles because we can't consciously control them. The final type of muscle is skeletal muscles, or "voluntary" muscles (voluntary because they only work when we tell them to). Skeletal muscles, which are attached to bone by tendons, produce movement by bending the skeleton at moveable joints. Skeletal muscles are the body's most abundant tissue.
Muscles move by contracting and then relaxing back to their original size. Muscles get the chemical energy necessary to perform this function from nutrients in the food we eat.
