muscle tone

Examples of muscle tone in the following topics:

• Muscle Tone

  • Muscle tone is a measure of a muscle's resistance to stretching while in a passive resting state.
  • Muscle tone is controlled by neuronal impulses and influenced by receptors found in the muscle and tendons.
  • The main regulator of muscle tone is the muscle spindle, a small sensory unit that is closely associated with and lies parallel to a muscle.
  • If tone decreases and the muscle stretches the spindle, an impulse results in a muscle contraction.
  • Muscle tone ensures that even when at rest the muscle is at least partially contracted.

• Abnormal Contractions of Skeletal Muscle

  • Involuntary muscle contractions are referred to as spasms, and can be due to abnormal activity of the nerve or the muscle.
  • In medicine, a spasm is a sudden, involuntary contraction of a muscle, a group of muscles, or a hollow organ, or a similarly sudden contraction of an orifice .
  • Examples of spasms include muscle contractions due to abnormal nerve stimulation, or abnormal activity of the muscle itself.
  • In this case, the hypertonic muscle tone is excessive and the muscles are unable to relax.
  • Hypertonic muscle spasms is the state of chronic, excessive muscle tone, or tension in a resting muscle – the amount of contraction that remains when a muscle is not actively working.

• Muscular Atrophy

  • People with sedentary jobs and senior citizens with decreased activity can lose muscle tone and develop significant atrophy.
  • Astronauts, free of the gravitational pull of Earth, can develop decreased muscle tone and loss of calcium from their bones following just a few days of weightlessness.
  • disease of the muscle itself.
  • Muscles, primarily voluntary muscles, become progressively weaker.
  • In some types of muscular dystrophy, heart muscles, other involuntary muscles and other organs are affected.

• Aging and the Digestive System

  • Aging can result in changes of the digestive system due to decreased nerve sensitivity, loss of muscle, and increased infection rate.
  • The changes associated with aging of the digestive system are largely caused by decreased nerve sensitivity, loss of muscle tone, and increased susceptibility to bacterial infection because of a weakened immune system.
  • Thus, changes include loss of strength and tone of muscular tissue and supporting muscular tissue, decreased secretory mechanisms, decreased motility of the digestive organs, along with changes in neurosensory feedback regarding enzyme and hormone release, and diminished response to internal sensations and pain.

• Benefits of Stretching

  • Stretching is a form of physical exercise, where specific skeletal muscles are stretched, improving elasticity and muscle tone.
  • Stretching is a form of physical exercise in which a specific skeletal muscle (or muscle group) is deliberately stretched, often by abduction from the torso, in order to improve the muscle's felt elasticity and reaffirm comfortable muscle tone.
  • Stretching can strengthen muscles, and in turn strong muscles are important to stretching safely and effectively.
  • Other research concludes that active stretching routines will reduce muscle-tendon viscosity and increase muscle compliancy and elasticity.
  • This may cause muscle injury in individual performance.

• Hypotonia and Hypertonia

  • Hypertonia is the reduced ability of muscles to stretch due to increased muscle tension; hypotonia, due to chronic reduced muscle tension.
  • Hypertonia is a reduction in the ability of a muscle to stretch due to increased muscle tension; it is caused by lesions to upper motor neurons.
  • Effects of hypertonia include spasticity dystonia (a state of prolonged muscle contractions) and rigidity (a state of muscle stiffness and decreased flexibility).
  • Hypotonia is the state of reduced muscle tone and tension, resulting in lessened ability to generate force from muscle contractions.
  • A muscle spindle, with γ motor neurons, sensory fibers and proprioceptor that detect the amount and rate of change of length in a muscle.

• Local Regulation of Blood Flow

  • Arterioles contain smooth muscle fibers in their tunica media which allows for fine control of their diameter.
  • Local responses to stretch, carbon dioxide, pH, and oxygen also influence smooth muscle tone and thus vasoconstriction and vasodilation.
  • However, the arterioles of skeletal muscle, cardiac muscle, and the pulmonary circulation vasodilate in response to these hormones acting on beta-adrenergic receptors.
  • Generally, stretch and high oxygen tension increase tone, and carbon dioxide and low pH promote vasodilation.
  • A number of hormones influence arteriole tone such as the vasoconstrictive epinephrine, angiotensin II and  endothelin and the vasodilators bradykinin and prostacyclin.

• Control of Muscle Tension

  • Muscle tension is influenced by the number of cross-bridges that can be formed.
  • The pull exerted by a muscle is called tension.
  • This is close to the maximum force the muscle can produce.
  • Muscle tension is produced when the maximum amount of cross-bridges are formed, either within a muscle with a large diameter or when the maximum number of muscle fibers are stimulated.
  • Muscle tone is residual muscle tension that resists passive stretching during the resting phase.

• Appropriate Tone

  • In writing, tone is defined as the author's attitude or emotion toward the subject and the reader.
  • Most business correspondence is written in the formal tone.
  • Even the most positive message can be misunderstood if the tone is not correct.
  • Most business correspondence is written in the formal tone .
  • In a negative message, it is best to use a gracious and sincere tone.

• Embellishing Tones

  • A passing tone is a non-chord tone (dissonance) that occurs between two chord tones, creating stepwise motion.
  • The typical figure is chord tone – passing tone – chord tone, filling in a third (see example), but two adjacent passing tones can also be used to fill in the space between two chord tones a fourth apart.
  • Like the passing tone, a complete neighbor tone is a non-chord tone (dissonance) that occurs between two chord tones; however, a complete neighbor tone will occur between two instances of the same chord tone.
  • Also like the passing tone, movement from the chord tone to the neighbor tone and back will always be by step.
  • Between those two instances of the chord tone are tow non-chord tones—one a step above and the other a step below the chord tone.