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.
Let's take a look at what occurs within a skeletal muscle, from excitation to contraction to relaxation 1  : An electrical signal (action potential) travels down a nerve cell, causing it to release a chemical message (neurotransmitter) into a small gap between the nerve cell and muscle cell. 2  This gap is called the synapse.he trigger for a muscle contraction is an electrical impulse. The electrical signal sets off a series of events that lead to crossbridge cycling between myosin and actin, which generates force.