wicked-naughtily or annoyingly playful; teasing and worrying with impish laughter; a wicked prank. impish, implike, mischievous, pixilated, prankish, puckish, arch. playful-full of fun and high spirits; playful children just let loose from school.
Inspiratory Muscles. The principal muscle of inspiration is the diaphragm, a domed sheet of muscle that separates the thoracic and abdominal cavities. The diaphragm attaches to the lower ribs, as well as to the lumbar vertebrae of the spine.
When myosin and actin interact, it results in a change in the shape of the muscle cells. Contractions happen when actin filaments actually slide over myosin filaments. This slide causes a change in the shape of the muscle cells producing movement, which is considered a muscle contraction. Depending on the muscle and the intended outcome of the contraction, muscles can either lengthen or shorten.