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).
Source(s): myself.... The only organ that helps you breath is your lungs. There are two muscle groups that help breath, the diaphragm and the intercostal muscles (the muscles between the ribs). The diaphragm will move up and down causing air to be inhaled or exhaled. When you breathe in you are increasing the pressure in your lungs, the muscles help with this.