Comprehensive Respiratory System: Ventilation, Diffusion, and Pathologies

What is a ventilation problem?

Air cannot move in and out of the lungs.

What is a diffusion problem?

Oxygen and carbon dioxide cannot cross the alveolar membrane.

What does ventilation-perfusion mismatch refer to?

Air and blood flow do not match in the lungs.

What happens during inspiration?

The diaphragm contracts, external intercostals contract, chest cavity expands, and air flows into the lungs.

What is the mnemonic for inspiration?

"IN = Increase space"

What occurs during expiration?

The diaphragm relaxes, chest cavity decreases, lung pressure increases, and air leaves the lungs.

What is the main muscle used in normal breathing?

The diaphragm.

What are accessory muscles used for?

They kick in during difficulty breathing, such as sternocleidomastoid and neck muscles.

What is the clinical clue for respiratory distress?

A patient leaning forward with neck muscles working.

Where does gas exchange occur?

At the alveoli and capillaries.

What affects diffusion in the lungs?

Thickness of the membrane and surface area.

What is surfactant's role in the lungs?

It keeps alveoli open and prevents collapse.

What is hypoxemia?

Low oxygen in arterial blood (low PaO₂).

What is hypoxia?

Cells are not receiving enough oxygen.

What is the definition of impaired ventilation?

Air cannot move properly in or out of the lungs.

What are two causes of impaired ventilation?

Airway obstruction and neuromuscular problems.

What is a common example of airway obstruction?

Asthma or COPD.

What is pulmonary embolism in terms of ventilation-perfusion problems?

Ventilated but not perfused; air arrives but no blood.

What is pneumonia in terms of ventilation-perfusion problems?

Perfused but not ventilated; blood arrives but no oxygen.

What are general signs of respiratory problems?

Barrel chest, respiratory distress, excess mucus, accessory muscle use, tachypnea, hemoptysis, exhaustion/confusion.

What do pulmonary function tests (PFT) measure?

Lung capacity and airflow.

What do ABGs measure?

PaO₂, PaCO₂, and pH to show oxygen and ventilation status.

What is the classic symptom of pneumonia?

Fever, chills, productive cough, sputum, fatigue, dyspnea, tachypnea, crackles, pleuritic chest pain.

What is the main problem in emphysema?

Destroyed alveoli leading to decreased surface area and gas exchange.

What is the main problem in chronic bronchitis?

Inflamed bronchi leading to increased mucus and thick airway walls.

What are the symptoms of asthma?

Wheezing, chest tightness, cough, dyspnea, anxiety.

What is ARDS?

Acute Respiratory Distress Syndrome characterized by severe inflammation and pulmonary edema.

What is the mnemonic for remembering the main problems of respiratory diseases?

"Wet alveoli" for pneumonia, "Empty holes" for emphysema, "Blue bloater" for chronic bronchitis, "Tight tubes" for asthma, "Drowning lungs" for ARDS.