Muscle contractions can be described based on two variables: force and length. Force itself can be differentiated as either … See more

In vertebrate animals, there are three types of muscle tissues: skeletal, smooth, and cardiac. Skeletal muscle constitutes the majority of muscle mass in the body and is responsible for locomotor activity. Smooth muscle… See more

In annelids such as earthworms and leeches, circular and longitudinal muscles cells form the body wall of these animals and are responsible for their movement. In an earthworm that is moving through a soil, for example, c… See more

In 1780, Luigi Galvani discovered that the muscles of dead frogs' legs twitched when struck by an electrical spark. This was one of the first forays into the study of bioelectricity, a field that still studies the electrical p… See more