The Structure, Function and Main Disorders of the Respiratory System

Structure of the Respiratory System:

Comprised of two parts: Upper respiratory tract (external nares, nasal cavity, pharynx, larynx) and lower respiratory tract (trachea, bronchi, and lungs).
Within the lungs, bronchi branch into smaller bronchioles, leading to alveoli, the tiny air sacs where gas exchange occurs.
The diaphragm, a strong muscle, sits under the lungs, and expands and contracts to facilitate breathing.

Function of the Respiratory System:

Primary purpose is to allow gas exchange – oxygen from the air we breathe in is absorbed into the blood, and carbon dioxide, a waste product, is expelled from the blood into the air we breathe out.
Participates in maintaining pH balance in the body by controlling levels of carbon dioxide - a key component of blood acidity.
Helps in vocalisation through the larynx, also known as the voice box.

Main Disorders of the Respiratory System:

Asthma: a chronic condition with symptoms such as wheezing, shortness of breath, chest tightness and coughing. It is often caused by inflammation and narrowing of the bronchial tubes.
Chronic Obstructive Pulmonary Disease (COPD): often caused by smoking, where the airway is progressively damaged leading to difficulty breathing.
Pneumonia: an infection where the alveoli of the lungs fill up with fluid or pus, making breathing painful and limiting oxygen intake.
Tuberculosis (TB): a serious bacterial infection that affects the lungs, causing severe coughing, weight loss, and fatigue.

To test your understanding, consider these questions:

Refer back to these notes regularly to reinforce your knowledge of the structure, function, and disorders of the respiratory system.