Earth is the homeworld of the Human race, located in the Sol System. It is the third planet of the system, orbiting at precisely 1 AU from its parent star, a G2-V Main Sequence star known as Sol, or simply The Sun. Contrary to popular belief, Earth is not the Federation's headquarters - it is Mars.
Exposure to. vertical vibrations in the 5-10 Hz range generally causes resonance in the thoracic-abdominal system, at 20-30. Hz in the head-neck-shoulder system, and at 60-90 Hz in the eyeball. When vibrations are attenuated in the. body, its energy is absorbed by the tissue and organs. The muscles are important in this respect. Vibration. leads to both voluntary and involuntary contractions of muscles, and can cause local muscle fatigue, particularly when the vibration is at the resonant-frequency level.
No doubt, calcium is a key component of strong bones but its presence in your muscles enables movement. Contraction and relaxation of your muscles occur because of rapidly changing concentrations of calcium inside your muscle cells, a biochemical process referred to as the calcium cycle.Too much or too little calcium in your blood may cause muscular symptoms due to disruption of the calcium cycle. tiny tube-like network called the sarcoplasmic reticulum, or SR, surrounds each myofilament. In a relaxed state, the SR contains a high concentration of calcium. The SR controls muscle contraction and relaxation by regulating calcium flow inside your muscle cells.