For other uses, see Fiction (disambiguation). An illustration from Lewis Carroll's Alice's Adventures in Wonderland, depicting the fictional protagonist, Alice, playing a fantastical game of croquet. Fiction is a story or similar work derived from imaginationâin other words, not based strictly on history or fact.
In human physiology, the muscles of respiration are those muscles that contribute to inhalation and exhalation, by aiding in the expansion and contraction of the thoracic cavity.The diaphragm and, to a lesser extent, the intercostal muscles drive respiration during quiet breathing.Additional 'accessory muscles of respiration' are typically only used under conditions of high metabolic demand (e.g. exercise) or respiratory dysfunction (e.g. an asthma attack).dditional 'accessory muscles of respiration' are typically only used under conditions of high metabolic demand (e.g. exercise) or respiratory dysfunction (e.g. an asthma attack).
Expiration is a passive process; the intercostal muscles and diaphragm that were once contracted, now relax. This causes the ribs to move down and diaphragm to move up. The surface tension of the fluid lining the alveoli diminishes the elasticity of the lung tissue and causes the alveoli to relax. The aforementioned action, coupled with the relaxation of the contracted respiratory muscles, relaxes the lungs.