Structures and their functions

• Lungs - the essential organs for respiration. Exchange carbon dioxide for oxygen and vice versa
• Bronchus - there are two. they are tubes that lead into the right and left lungs
• Pharynx - aka throat - is a passageway for air and food
• Larynx - a passageway for air (aka voice box). There is a valve to close off the air passage from the digestive passage.
• Trachea - allows air to pass beyond the larynx to where it divides into the left and right Bronchi. Also provides protection to the digestive system.
• Bronchioles - each bronchus divides and subdevides into smaller branches. By the time the air has reached here from outside, it has been warmed up to body temperature and filtered.
• Alveoli - these are tiny air sacs that allow for the gas exchange between the respiratory and circulatory systems.
• Diaphragm - dome shape muscle that sits just below the lungs. It contracts and relaxes to change the pressure in the chest cavity to create breathing.