Figure 1: The Human Respiratory System(from http://kvhs.nbed.nb.ca/gallant/biology/mammalian_respiratory_system.html)The respiratory system consists of the structures involved in ventilation (the exchange of air between the atmosphere and the lungs) and gas exchange (the exchange of oxygen and carbon dioxide between the lungs and the blood) [5, 7]. This includes the conducting system (the passages which lead from the external atmosphere to the exchange surface of the lungs), the alveoli (the network of sacs that form the surface where oxygen moves from the inhaled air to the blood and carbon dioxide from the blood moves to the air to be exhaled), and the bones and muscles of the chest cavity (the thorax) that assist in ventilation [2, 8]. The respiratory system can be divided into two parts: the upper respiratory tract, consisting of the nasal cavity, pharynx, and larynx, and the lower respiratory tract, consisting of the trachea,two primary bronchi and the bronchioles and alveoli, and the lungs [2].
Fun fact! The entire surface area of the alveoli, if spread out, would cover an entire tennis court-- approximately 70-100 square meters [9].
Fun fact! The entire surface area of the alveoli, if spread out, would cover an entire tennis court-- approximately 70-100 square meters [9].
