Breathing Basics: Anatomy, Physiology, and Common Ailments

Pulmonary Ventilation Explained

Pulmonary ventilation refers to the processes that facilitate airflow between the atmosphere and the alveoli through inspiration and expiration.

Physiology of Breathing

Breathing is performed by muscles that change the volume of the chest cavity, creating pressures that move air in and out of the lungs. During normal breathing, at rest, inspiration is active, while expiration is passive.

The diaphragm, the main inspiratory muscle, causes the movement of the rib cage down and out, changing the size of the chest cavity horizontally. Other muscles involved in ventilation include the intercostal muscles, abdominal muscles, and accessory muscles.

Respiratory System Anatomy

Respiratory organs are responsible for transporting oxygen to the blood and tissues, as well as expelling carbon dioxide from the body.

Upper Respiratory Tract

• Nostrils: Entry point for oxygen and exit for carbon dioxide.
• Pharynx: Connects the nose and mouth to the larynx and esophagus; air passes through it.

Lower Respiratory Tract

• Larynx: Contains the vocal cords. When swallowing food, the epiglottis closes to prevent aspiration.
• Trachea: Extends from the larynx to the bronchial tubes, providing an open airway for inhaled and exhaled air.
• Lungs: Contain the bronchi, bronchioles, and alveoli, which are crucial for gas exchange, ensuring oxygen enters the bloodstream and carbon dioxide is expelled.
• Bronchi: These tubes branch from the trachea, directing inhaled air into the lungs, which then process the air to take in needed elements and expel harmful ones.
• Bronchioles: Smaller airways that branch from the bronchi; oxygen passes through them before reaching the alveoli.
• Alveoli: Tiny air sacs that receive air from the bronchioles. Here, oxygen atoms enter the bloodstream during gas exchange.

Common Respiratory Diseases

• Flu (Influenza-like Illness): A respiratory tract infection characterized by high fever, sneezing, headache, and muscle pain.
• Common Cold: Primarily caused by viruses, symptoms include nasal itching, sneezing, nasal obstruction, and mucus.
• Influenza: A highly contagious acute viral disease caused by virus A, B, and C. Symptoms include fever, headache, intense muscle pain, fatigue, and dry cough.