Muscles have several main functions, including locomotion, heat production, structural support and muscle contractions. Muscles are dense and account for nearly 40 percent of the body's weight.Know More
There are three primary types of muscles: skeletal muscles, smooth muscles and cardiac muscle. Skeletal muscles control movements of the body. Limb movement occurs when muscle fibers attached to the bones contract. Muscle contraction is a voluntary response controlled by neural functions that release the energy needed to cause the reaction. The framework, posture and joints of the body are supported by skeletal muscles. Skeletal muscles also contribute to heat production when necessary, which is a sign of metabolic activity. Cardiac muscles are located exclusively in the heart. Blood circulation is dependent on cardiac muscle contractions, which supply the body with oxygenated blood.
Muscle tissue is cased in a material made up of connective tissue called fascia. Inside the fascia are bundles of muscle fibers known as fasciculus that are directly responsible for muscle function. Individual muscle fibers are multinucleated and striated, surrounded by a material called perimysium. These fibers are surrounded by sarcoplasm and a cell membrane called sarcolemma. Myofibrils are protein-based filaments found in the sarcoplasm that contain the necessary information for proper muscle fiber function.Learn more about Muscles
Six extraocular muscles allow the eyeballs to move: the inferior, superior, lateral and medial rectus muscles together with the inferior and superior oblique muscles. Vision Aware adds that the muscles that move the eyeballs are attached to the sclera, a white outer coating that covers the eyeball.Full Answer >
When muscle and bone tissue are not used, they will begin to shrink and waste away, known as atrophy. Atrophy, even minor, in muscle or bone can cause some loss of strength and motion. Some atrophy can normally occur as people age.Full Answer >
The three types of muscle tissue include smooth muscle, cardiac muscle and skeletal muscle. Each type of muscle has a specific function in the human body.Full Answer >
The diaphragm is made of skeletal muscle tissue. Any cell that has the ability to contract is considered a muscle cell. Skeletal muscles are typically voluntary muscles, which means that people can control when they contract and relax.Full Answer >