An individual muscle fiber may also be called a myofiber or a muscle cell. Each muscle fiber is a single, narrow cell that spans the entire length of a muscle. There are three different kinds of myofibers found in the body: skeletal, cardiac and smooth.Know More
Myofibers are composed mostly of cylindrical bundles of proteins. There are two different types of protein filaments found in each muscle fiber: actin and myosin. When these filaments slide past one another, the muscle contracts. Each myofiber is surrounded by a membrane called a sarcolemma. Groups of muscle fibers are bundled together and encapsulated in connective tissue to form an entire muscle.
The cells that compose skeletal muscles, which are the muscles that connect to the bones and allow individuals to run, bend their arms and turn their heads, are voluntary, which means that each person decides when to contract them. Most of the muscles in the body are skeletal muscles, and they comprise an average of 40 percent of a person's body mass. Cardiac muscle cells, which are found in the heart, and smooth muscle cells that line the intestines and blood vessels, are involuntary, which means that the brain automatically controls their contractions.Learn more about Muscles
The endomysium is the protective covering of connective tissue that surrounds each individual muscle fiber. Blood vessels, or capillaries, nerves and lymphatics also make up this layer.Full Answer >
Muscle spasms are sudden involuntary contractions of one or more muscles and often lead to cramping. Some muscles are more prone to spasms, including the calf muscles and abdominal region. Causes include vitamin deficiency, magnesium or potassium deficiency and fatigue.Full Answer >
According to Healthline, muscle rigidity is a condition in which the muscles are continually tense or contracted. Muscle rigidity is often a symptom of neurological problems or medicinal side effects.Full Answer >
The tongue is mostly made up of muscle, but it also contains fat, glands and a mucus membrane. The extrinsic and intrinsic muscles in the tongue are skeletal muscles, which means that they are voluntarily controlled by the central nervous system.Full Answer >