The main function of the respiratory system is to transfer gases between the air and blood. The system is comprised of tubes and highly branched channels, which terminate in dead-end sacs where gas transfer occurs. Air brought into the body is conditioned and filtered in the first part of the respiratory system, the conducting portion (nasal cavity to bronchioles). The second part of the system, the respiratory portion, consists of the respiratory bronchioles and alveoli that are involved with gas exchange.

The learning objectives for this session are:

1. Identify the characteristic microscopic structural and cellular components of the respiratory system from the nasal cavity to the alveolus.
2. Identify the structural components of the nasal cavity, including the organization of the respiratory and olfactory mucosa and explain their function, respectively, in respiration and in producing the sense of smell.
3. Identify the structural features of the larynx, comparing and contrasting the true and false vocal folds.
4. Recognize and describe the structural features and functions of the conducting and respiratory portions of the respiratory system.
    

Let's start at the top with the nasal cavity.