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).
Breathing and stress. The primary role of breathing is to absorb oxygen and to expel carbon dioxide through the movement of the lungs. Muscles that control the movement of the lungs are the diaphragm (a sheet of muscle underneath the lungs) and the muscles between the ribs. When a person is under stress, their breathing pattern changes.