The muscular system is responsible for allowing us to move. Muscles make up quite a large part of the body and make up more than one-third of our body mass. Muscles are able to contract and relax which allows the body to move and performs all bodily actions. In addition, muscles provide the force that push substances such as food through the body.
Muscular System: The organ system that includes all the muscles of the body.
Muscle Fiber: A muscle cell.
Tendon: Tough connective tissues which attach skeletal muscles to the skeleton.
Myofibrils: Bundles of threadlike structures that are found in muscle fiber.
Sarcomere: Basic functional unit of the muscle.
Sliding Filament Theory: Theory explaining how muscle fibers contract
Skeletal Muscle: Muscle tissue that is attached to bone.
Cardiac Muscle: Muscle that is found only in the walls of the heart.
Smooth Muscle: Muscle tissue in the walls of internal organs such as the stomach.
The muscular system is made up of all of the muscles of the body.
Image Credit: Polarlys, GNU-FDL 1.2
Image Credit: Nathanael Reveal, GNU-FDL 1.2
Muscles are made up of muscle fibers, which each contain hundred of myofibrils. Myofibrils are made up of repeating sections of sarcomeres.
Sacromeres are what gives the striated appearance to muscles.
The sliding filament theory explains how actin and myosin interact to contract muscle fibers: