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 the ventricles relax, atrial pressure exceeds ventricular pressure, the AV valves are pushed open and blood flows into the ventricles. However, when the ventricles contract, ventricular pressure exceeds atrial pressure causing the AV valves to snap shut. To ensure that the AV valves do not evert (turn inside-out), they are attached to small papillary muscles by tough tendons called the cordae tendineae.