Lungs Structure and Function

Anatomy
- Located in the thoracic cavity, protected by the rib cage.
- Composed of two main parts: right lung (three lobes) and left lung (two lobes).
- Surrounded by pleura, a double-layered membrane that provides lubrication.
Functional Units
- Alveoli: Tiny air sacs where gas exchange occurs; lined with surfactant to reduce surface tension.
- Bronchial Tree: Includes bronchi, bronchioles, and terminal bronchioles; facilitates air passage and filtration.
Vascular Supply
- Pulmonary arteries: Carry deoxygenated blood from the heart to the lungs.
- Pulmonary veins: Return oxygenated blood to the heart.

Gas Exchange
- Oxygen enters the bloodstream; carbon dioxide is expelled.
- Occurs through diffusion in the alveoli.
Regulation of Blood pH
- Helps maintain acid-base balance through CO2 removal.
Defense Mechanism
- Mucociliary escalator traps and removes pathogens and debris.
- Alveolar macrophages protect against infections.
Sound Production
- Vocal cords in the larynx (above the trachea) vibrate to produce sound.

Asthma
- Chronic inflammation leading to airway narrowing and difficulty breathing.
- Symptoms: wheezing, coughing, shortness of breath.
Chronic Obstructive Pulmonary Disease (COPD)
- Progressive lung disease characterized by airflow limitation.
- Includes chronic bronchitis and emphysema.
- Symptoms: chronic cough, sputum production, and exertional dyspnea.
Pneumonia
- Inflammation of lung tissue caused by infection (bacterial, viral, fungal).
- Symptoms: cough, fever, difficulty breathing, chest pain.
Pulmonary Fibrosis
- Scarring of lung tissue leading to reduced lung capacity and impaired gas exchange.
- Can result from environmental exposures or autoimmune diseases.
Lung Cancer
- Uncontrolled growth of lung cells; major types include small cell and non-small cell lung cancer.
- Symptoms: persistent cough, chest pain, weight loss, and coughing up blood.
Tuberculosis (TB)
- Infectious disease caused by Mycobacterium tuberculosis.
- Symptoms: persistent cough, night sweats, and weight loss.

Avoiding Risk Factors
- Quit smoking; reduce exposure to pollutants and allergens.
- Vaccinations (e.g., for influenza and pneumonia).
Management Techniques
- Use of bronchodilators and corticosteroids for asthma and COPD.
- Pulmonary rehabilitation programs for chronic lung diseases.
Regular Check-ups
- Early detection through screenings, especially in high-risk populations.

Lungs are located in the thoracic cavity, safeguarded by the rib cage.
The right lung consists of three lobes, while the left lung has two lobes.
Surrounding the lungs is the pleura, a double-layered membrane that allows for lubrication.
Alveoli: Microscopic air sacs where the exchange of oxygen and carbon dioxide occurs, lined with surfactant to minimize surface tension.
Bronchial Tree: Comprises bronchi, bronchioles, and terminal bronchioles, responsible for air passage and filtration.
Vascular Supply:
- Pulmonary arteries carry deoxygenated blood from the heart to the lungs for oxygenation.
- Pulmonary veins transport oxygenated blood back to the heart.

Gas exchange facilitates oxygen entry into the bloodstream and the expulsion of carbon dioxide through diffusion in alveoli.
The lungs help regulate blood pH by removing carbon dioxide, contributing to the acid-base balance in the body.
Defense mechanisms include the mucociliary escalator, which traps and removes pathogens, alongside alveolar macrophages that combat infections.
Sound production occurs as vocal cords in the larynx vibrate, generating sound.

Asthma: Characterized by chronic inflammation, airway narrowing, and difficulty in breathing; symptoms include wheezing, coughing, and shortness of breath.
Chronic Obstructive Pulmonary Disease (COPD): A progressive condition marked by airflow limitation; includes chronic bronchitis and emphysema. Symptoms involve chronic cough, sputum production, and exertional dyspnea.
Pneumonia: Inflammation of lung tissue due to infection (bacterial, viral, fungal), presenting symptoms such as cough, fever, difficulty breathing, and chest pain.
Pulmonary Fibrosis: Scarring of lung tissue resulting in reduced lung capacity and compromised gas exchange; often caused by environmental factors or autoimmune diseases.
Lung Cancer: Distinguished by uncontrolled cellular growth, subdivided into small cell and non-small cell types; symptoms include persistent cough, chest pain, weight loss, and hemoptysis.
Tuberculosis (TB): An infectious disease induced by Mycobacterium tuberculosis, exhibiting symptoms like prolonged cough, night sweats, and weight loss.

Minimize risk factors by quitting smoking and limiting exposure to pollutants and allergens; vaccinations for influenza and pneumonia are recommended.
Management techniques include bronchodilators and corticosteroids for asthma and COPD, as well as pulmonary rehabilitation for chronic lung diseases.
Regular health check-ups and screenings are crucial for early detection, especially in individuals at high risk.

Positioned in the thoracic cavity, safeguarded by the rib cage for protection.
Comprised of the right lung with three lobes and the left lung with two lobes.
Enclosed by pleura, a double-layered membrane that reduces friction during lung expansion.
Alveoli are essential for gas exchange; these minuscule air sacs are coated with surfactant to lower surface tension and facilitate breathing.
The Bronchial Tree branches into bronchi, bronchioles, and terminal bronchioles, which allow for the passage and filtration of air.
Vascular Supply includes:
- Pulmonary arteries transport deoxygenated blood from the heart to the lungs for oxygenation.
- Pulmonary veins carry oxygenated blood back to the heart.

Primary role in Gas Exchange allows oxygen intake into the bloodstream while expelling carbon dioxide.
Gas exchange occurs via diffusion in the alveoli, optimizing oxygen absorption and waste removal.
Maintains Regulation of Blood pH by controlling carbon dioxide levels to help sustain acid-base balance.
Acts as a Defense Mechanism:
- Mucociliary escalator removes pathogens and debris from the airways.
- Alveolar macrophages provide protection against infections residing in the lungs.
Facilitates Sound Production through vocal cords that vibrate in the larynx, generating sound during speech.

Asthma: A chronic condition marked by airway inflammation, causing narrowing and difficulty in breathing. Symptoms include wheezing, coughing, and shortness of breath.
Chronic Obstructive Pulmonary Disease (COPD): A progressive illness characterized by airflow limitation, encompassing chronic bronchitis and emphysema. Common symptoms are chronic cough, sputum production, and breathlessness during exertion.
Pneumonia: An infection-induced inflammation of lung tissue, potentially bacterial, viral, or fungal. Symptoms include cough, fever, breathing difficulties, and chest pain.
Pulmonary Fibrosis: Involves scarring of lung tissue that diminishes lung capacity and adversely affects gas exchange, often resulting from environmental toxins or autoimmune disorders.
Lung Cancer: Characterized by unregulated growth of lung cells, with primary types being small cell and non-small cell lung cancer, often linked to smoking and environmental exposures.