Function
There are more than 600 muscles in the human body - most of them are skeletal muscle. Skeletal muscles can be attached to the skeleton by tendons, while others are attached to the skin. Smooth muscles are found in hollow organ and blood vessels while cardiac muscles are only found in the heart.
Movement
The main function of all muscles of the Muscular System is movement.
There are three basic muscles types found in the body, and they each move something.
- Skeletal muscles move the skeleton
- Cardiac muscles move the blood
- Smooth muscles move the contents of your hollow organs
Posture
Specialized muscle contractions allow your muscular system to counteract gravity all day long. Gravity would naturally pull your head and torso forward toward the ground, but muscles in your neck and back keep you standing upright all day.
Specialized muscle contractions allow your muscular system to counteract gravity all day long. Gravity would naturally pull your head and torso forward toward the ground, but muscles in your neck and back keep you standing upright all day.
Heat Production
Our survival depends on our ability to maintain a constant body temperature - for humans that is 37°C (98.6°F). The contraction of muscle fibers produces most of the heat required to maintain our body temperature. Most of the energy released from the break down of ATP during a muscular contraction is used to shorten the muscle fiber, but what isn't used for movement is lost as heat during the chemical reaction. |
Structure
Skeletal muscle fibers (cells) are packaged into organs called skeletal muscles that attach to the body's skeleton. These fibers are large and multinucleate. Many of these cells run the length of the entire muscle it makes up - making some muscle cells almost 1 foot in length! Some individual fibers are so large they can be seen with the naked eye.
Each muscle fiber is wrapped in a delicate sheath of connective tissue called the endomysium.
Several endomysium-covered fibers are bundled together by a tougher fibrous membrane called the perimysium to form a fascicle. Larger bundles of fascicles are held together by yet a stronger layer of connective tissue known as the epimysium, which encapsulates the entire muscle. Epimysia coordinate together to become either cordlike tendons or sheetlike aponeuroses which both serve to attach muscles to either bones, cartilages or connective tissue coverings. Tendons not only act to anchor muscles to bones. Their strong and tough structure allows them to pass directly over rough bony projects, which would typically tear delicate muscle tissue. They are also much smaller than muscle, which helps to conserve space inside your joints. |
|
Structure & Function Muscle Movements Roles of Muscles Microscopic Structure Contractions Nerve Supply Energy Tone
Myology: Head Myology: Anterior Torso Myology: Posterior Torso Myology: Upper Extremity Myology: Lower Extremity
Injuries & Pathologies
MUSCULAR SYSTEM
Myology: Head Myology: Anterior Torso Myology: Posterior Torso Myology: Upper Extremity Myology: Lower Extremity
Injuries & Pathologies
MUSCULAR SYSTEM