You can elect to use a 52-53-week tax year if you keep your books and records and report your income and expenses on that basis. If you make this election, your 52-53-week tax year must always end on the same day of the week.
Forced Inhalation. Involved in the mechanics of breathing; The muscles involved in this type of breathing are the diaphragm, the external intercostal muscles, and the accessory respiratory muscles (activated when respiration increases significantly).
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).long with the diaphragm, the intercostal muscles are one of the most important groups of respiratory muscles. These muscles are attached between the ribs and are important in manipulating the width of the rib cage.