Functions of the respiratory system:
- Providing a large surface area for gaseous exchange between air and circulating blood.
- Moving air to and from the exchange surfaces of the lungs along the respiratory passageways.
- Protecting respiratory surfaces from dehydration, temperature changes, or other environmental variations, and defending the respiratory system and other tissues from pathogens.
- Producing sounds for speaking, singing, and other forms of communication.
- Facilitating the detection of odors by olfactory receptors in the superior portions of the nasal cavity.
Capillaries of the lung help to regulate blood volume and blood pressure
ORGANISATION OF THE RESPIRATORY SYSTEM
Upper respiratory system- consists of nose, nasal cavity, paranasal sinuses, and pharynx (throat).
These passageways filter, warm, and humidify incoming air and protects the more delicate surfaces of the lower respiratory system. They also reabsorb heat and water from outgoing air.
Lower respiratory system- consists of the larynx, trachea, bronchi, bronchioles and alveoli.