Voluntary muscles: are those whose contraction is under the control of will of individual. e.g. muscles of limbs.
Involuntary muscles: are those whose contraction is not controlled by will of individual e.g. heart, stomach muscles etc.
Myofilaments: are proteins filaments present in sarcomeres and take part in muscle contraction e.g. actin, myosin.
Myofibrils: are fine fibrillar structures stacked into a muscle cell. Each myofibril contains hundreds of sarcomeres joined end to end with each other.
Tetanus: is a state of continuous contraction of muscle without undergoing relaxation. This occurs due to tetanus toxin produced by clostridium bacteria.
Fatigue: is state of refusal of muscle to undergo contraction upon stimulation. This occurs when the muscle is depleted of its energy reserve due to prolonged contractions.
