Purpose
Unconscious nerve impulses maintain the muscles in a partially contracted state. If a sudden pull or stretch occurs, the body responds by automatically increasing the muscle's tension, a reflex which helps guard against danger as well as helping to maintain balance. Such near-continuous innervation can be thought of as a "default" or "steady state" condition for muscles. There is, for the most part, no actual "rest state" insofar as activation is concerned. Both the extensor and flexor muscles are involved in the maintenance of a constant tone while "at rest". In skeletal muscles, this helps maintain a normal posture.
Although cardiac muscle and smooth muscle are not directly connected to the skeleton, they also have tonus in the sense that although their contractions are not matched with those of antagonist muscles, the non-contractile state is characterized by (sometimes random) enervation.
Read more about this topic: Muscle Tone
Famous quotes containing the word purpose:
“God sent children for another purpose than merely to keep up the race—to enlarge our hears; and to make us unselfish and full of kindly sympathies and affections; to give our souls higher aims; to call out all our faculties to extended enterprise and exertion; and to bring round our firesides bright faces, happy smiles, and loving, tender hearts.”
—Mary Botham Howitt (20th century)
“War is in truth a disease in which the juices that serve health and maintenance are used for the sole purpose of nourishing something foreign, something at odds with nature.”
—Johann Wolfgang Von Goethe (1749–1832)
“... the word “education” has an evil sound in politics; there is a pretense of education,
when the real purpose is coercion without the use of force.”
—Hannah Arendt (1906–1975)