The muscular system is one of the largest and most important body systems. There are three types of muscle present throughout the body: skeletal, cardiac and smooth muscle. The muscular system functions to allow the body to produce movement and allows our internal organs to function as they should. The muscular system is involved in almost every function of the body, including function of the heart, breathing, digestion and regular daily activities such as walking and running.
Skeletal Muscle
Skeletal muscles are attached to bones and are under both voluntary and involuntary control. The skeletal muscles under voluntary control are those that can be activated as an individual needs and desires. Involuntary skeletal muscles are controlled without thought and generally function for longer periods of time than those under voluntary control. An example of involuntary skeletal muscles are those that control posture. The muscles function in pairs along with another muscle to produce movement. One muscle moves the bone in one direction and the other muscle moves the bone in the opposite direction. There are over 650 skeletal muscles throughout the body and all of these vary in size.
Cardiac Muscle
Cardiac muscle is found only in the heart. Cardiac muscle is classified as a twitch muscle, meaning it only contracts in short, single contractions. This type of muscle is under involuntary control and has properties of both smooth and skeletal muscle. According to "The Atlas of Anatomy," the cardiac muscles contract in an organized manner and regulate the beating of the heart. Cardiac muscle can stretch like smooth muscle and can contract like skeletal muscle.
Smooth Muscle
Smooth muscle is found in the internal organs, along the digestive tract and in the uterus. Smooth muscles are under involuntary control and are controlled automatically by the nervous system. Smooth muscles are involved in functions such as digestion, bladder control and breathing.
Ligaments and Tendons
Ligaments and tendons are very similar in their structure and makeup, but are very different in their specific functions. Both ligaments and tendons are strong sheets of connective tissues. Ligaments are responsible for attaching bone to bone. Tendons are responsible for attaching muscles to bone. Physical exercise can strengthen tendons and their attachment to bones, which will help avoid injury.
Muscle Health
All muscles naturally decrease in size and power with age. Regular exercise can help maintain muscle tone and strength. Proper nutrition, drinking adequate amounts of water, getting appropriate and regular rest, and reducing stress also help maintain a healthy muscular system.
References
- The Human Body: The Muscular System
- "Atlas of Anatomy;" Giovanni Iazzetti, Enrico Rigutti; 2006
- Internet FAQ Archives--Online Education: The Muscular System - Taking care: Keeping the Muscular System Healthy
- Best Health, Wake Forest University Baptist Medical Center: Muscular System
