The primary function of the respiratory system is gas exchange, exchanging carbon dioxide for oxygen. It has secondary functions of olfaction and sound production. The main components include the nose, pharynx, larynx, trachea, lungs, and bronchial tree. The nose warms, moistens, and filters incoming air and produces sound. It has external cartilage and skin and internal nasal cavities separated by the nasal septum. The pharynx is a common tube that functions as an important junction. It contains the nasopharynx, oropharynx, and laryngopharynx. The pharynx contains tonsils that screen microorganisms and attack them with immune cells. Hum

1. Respiratory System What is its primary function?

2. Gas exchange: Exchanging carbon dioxide (CO 2 )for oxygen (O 2 ). Primary Function:

3. Secondary (additional, important) functions: Olfaction Sense of smell Sound production Vocal cord vibration coupled with resonance

5. The Nose

6. Nose Special organ for the sense of smell , but it is also the entrance to the respiratory tract . It warms, moistens, and filters the incoming air, and it serves as a resonating chamber for producing sound.

9. The Pharynx Pharynx

10. Pharynx Common tube 5 inches long which functions as an important junction point for several passages leading into and out of the body. Pharynx

11. Pharynx Substances entering the body, thus passing through the pharynx, can exit the pharynx via the larynx & trachea or the esophagus , or can be ejected from the pharynx back out the nasal cavity (internal nose) or oral cavity (mouth), due to the “gag” reflex. There are three parts to the pharynx: Pharynx

15. The pharynx also contains the tonsils : Tonsils act as first line defenders, screening out microorganisms from the air, food, and liquids that enter the body through the nose and mouth, and attacking them with phagocytic cells. Humans actually have three sets of tonsils – one set per subdivision of the pharynx.

17. #2 Oropharynx 2. Palatine tonsils – often called “the tonsils” they are found in the walls of the oropharynx (throat).

18. #3 Laryngopharynx 3. Lingual tonsils – lie at the back of the tongue just below the palatine tonsils and above the epiglottis.