Module 3: Respiratory System

Function of the respiratory system

Gas exchange supplying the body with oxygen and removes carbon dioxide, conditions incoming air and contributes to smell and sound production

Conditions for effective gas exchange

Incoming air must be clean, warm and moist

Major functions of the respiratory system

-gas exchange

-air conditioning

-protection

-olfaction

-sound production

-conducting air

Two major divisions of the respiratory tract

Upper respiratory tract and lower respiratory tract

Upper respiratory tract

Primarily the nose, nasal cavity and pharynx

Lower respiratory tract

Structures below the pharynx including the larynx, trachea, bronchi, bronchioles, lungs

Conducting zone

Conducts air toward the lungs and conditions it by filtering, warming and humidifying it which extends from the nose to the bronchioles

Respiratory zone

The region where gas exchange occurs between air and blood primarily at the respiratory bronchioles, alveolar ducts and alveoli

Major structures of the URT

Nose, nasal cavity, paranasal sinuses, pharynx

Functions of the nose

Provides an open pathway for airflow, filters large particles, helps warm and humidify air, contains receptors involved in smell

External nares

The openings through which air enters the nose (nostrils)

Nasal septum

Divides the nasal cavity into right and left sides helping organise the two nasal passages

Nasal vestibule

The entrance region immediately inside the nostrils lined by stratified squamous epithelium and contains vibrissae

Vibrissae

Coarse hairs located in the nasal vestibule which trap larger particles and debris

Nasal cavity

The space behind the nose that inhaled air travels, important for filtering, warming, humidifying and smelling air

Internal nares

The openings of the nasal cavity that connect it to the nasopharynx