Pulmonology: Medical Terminology

Definition and Word Parts

Pulmonology is the medical specialty focused on the study of the respiratory system, including its anatomy, physiology, diseases, and treatments. Understanding medical terminology is essential for proficiency in this area.

• pulmon/o-: means lung

• -logy: means study of

Respiratory System Overview

Major Structures

The respiratory system consists of the lungs and associated structures that form a pathway for air to flow into and out of the body. It is divided into upper and lower respiratory tracts.

• Lungs: Main organs responsible for gas exchange

• Pathways: Nose, pharynx, larynx, trachea, bronchi, bronchioles, alveoli

Anatomy: Upper Respiratory System

Nose and Nasal Cavity

The nose is the entry point for air and contains the nasal cavity, which is divided by the septum. Turbinates slow airflow, allowing air to be warmed and moistened. The nasal mucosa lines the cavity, producing mucus to humidify air and trap particles.

• Turbinates: Slow airflow for warming and moistening

• Nasal mucosa: Humidifies air, produces mucus

• Cilia: Move mucus and debris out of the nasal cavity

Air Filtration and Humidification

Air entering the nasal cavity swirls around the turbinates, allowing the mucosa to warm and moisten the air. Cilia move in waves to clear away mucus and inhaled debris, helping maintain core body temperature and protect the lungs.

• Mucus and hair: Trap particles and prevent them from reaching the lungs

• Importance: Especially critical in cold or dry environments

Anatomy: Upper Respiratory System

Pharynx

The pharynx is a common passage for inhaled air, exhaled air, and swallowed food. It has three parts: nasopharynx, oropharynx, and laryngopharynx.

• Nasopharynx: Uppermost part, behind the nasal cavity

• Oropharynx: Middle part, behind the oral cavity

• Laryngopharynx: Lowest part, leading to the larynx and esophagus

Anatomy: Lower Respiratory System

Larynx

The larynx, or voice box, remains open during breathing and contains the vocal cords. During swallowing, the larynx moves up to the epiglottis, preventing food from entering the lungs.

• Vocal cords: Produce sound when air is exhaled

• Epiglottis: Covers the larynx during swallowing

Trachea, Bronchi, Bronchioles, and Alveoli

The trachea (windpipe) is a passageway for air, supported by C-shaped cartilage rings. It divides into right and left bronchi, which enter the lungs and branch into bronchioles. Bronchioles end in alveoli, clusters of microscopic air sacs where gas exchange occurs.

• Trachea: Rigid anteriorly, soft posteriorly

• Bronchi: Main branches entering the lungs

• Bronchioles: Smaller branches within the lungs

• Alveoli: Sites of oxygen and carbon dioxide exchange

Lungs

The lungs are spongy, air-filled structures. The right lung has three lobes (upper, middle, lower), while the left lung has two lobes (upper, lower). The apex is the rounded top of the lung.

• Right lung: RUL, RML, RLL

• Left lung: LUL, LLL

• Apex: Top of the lung

Alveoli and Pulmonary Parenchyma

Inside the lung, bronchi branch into bronchioles ending in alveoli. Alveoli are hollow spheres of cells that exchange oxygen and carbon dioxide with capillaries. They secrete surfactant to prevent collapse and collectively form the pulmonary parenchyma.

• Surfactant: Reduces surface tension, prevents alveolar collapse

• Pulmonary parenchyma: Functional tissue of the lung

Thorax and Pleura

The thorax is the area between the base of the neck and the diaphragm. The rib cage forms the bony wall, and the mediastinum lies between the lungs. The diaphragm is the inferior border. The pleurae are membranes that cover the lungs and line the thoracic cavity, secreting pleural fluid.

• Visceral pleura: Covers the lung surface

• Parietal pleura: Lines the thoracic cavity

• Pleural fluid: Lubricates pleural surfaces

Physiology: Breathing and Respiration

Breathing Mechanisms

Breathing is involuntary, regulated by respiratory control centers in the brain. The phrenic nerve stimulates the diaphragm. Inhalation (inspiration) and exhalation (expiration) are the two main phases.

• Inhalation: Diaphragm contracts, thoracic cavity enlarges, air flows in

• Exhalation: Diaphragm relaxes, thoracic cavity shrinks, air flows out

Processes of Respiration

Respiration involves five processes:

1. Ventilation: Movement of air in and out of the lungs

2. External respiration: Exchange of gases between blood and lungs

3. Gas transport: Movement of gases by the blood

4. Internal respiration: Movement of oxygen from blood to cells

5. Cellular respiration: Use of oxygen by cells to generate energy; production of carbon dioxide as waste

Diseases of the Respiratory System

Upper Respiratory Diseases

Upper respiratory infection (URI) is a bacterial or viral infection of the upper respiratory tract, commonly known as a head cold. It spreads by contact or inhalation of particles.

• Antibiotics: Effective against bacterial infections

• Transmission: By droplets or contact

Lower Respiratory Diseases

Common diseases include asthma, bronchiectasis, bronchitis, and chronic obstructive pulmonary disease (COPD). Asthma is characterized by hyperreactivity of bronchi, inflammation, excess mucus, and bronchospasm. COPD includes chronic bronchitis and emphysema, often due to smoking or pollution.

• Asthma: Bronchospasm, inflammation, excess mucus

• Bronchiectasis: Permanent enlargement of bronchioles

• Bronchitis: Infection or inflammation of bronchi

• COPD: Chronic inflammation, severe coughing, shortness of breath

Lung Diseases

Diseases affecting the lungs include pneumonia, pulmonary edema, pulmonary embolism, tuberculosis, and cystic fibrosis. Pneumonia is an infection of the lung lobes, causing fluid and white blood cells to fill passages. Pulmonary embolism is a blockage of a pulmonary artery by an embolus.

• Pneumonia: Bacterial, viral, aspiration, lobar, panlobar, pneumococcal, walking pneumonia

• Pulmonary edema: Fluid buildup in alveoli

• Pulmonary embolism: Blockage by blood clot or fat globule

• Tuberculosis: Caused by Mycobacterium tuberculosis, forms nodules in lungs

• Cystic fibrosis: Inherited, thick mucus blocks alveoli, frequent infections

Laboratory Tests and Diagnostic Procedures

Common Tests

Several laboratory and diagnostic tests are used to assess respiratory function and diagnose diseases.

• Arterial blood gases (ABGs): Measures oxygen and carbon dioxide in arterial blood

• Oximetry: Measures oxygen saturation of hemoglobin

• Pulmonary function test (PFT): Measures lung volumes and capacities

• Sputum culture and sensitivity (C&S): Identifies causative bacteria and antibiotic sensitivity

• Tuberculosis tests: Tine, Mantoux, acid-fast bacillus, Xpert sputum

Radiologic and Nuclear Medicine Procedures

Imaging Techniques

Imaging is essential for diagnosing respiratory diseases.

• Chest radiography (CXR): X-ray imaging of the lungs

• Computerized axial tomography (CAT, CT): Cross-sectional imaging

• Lung scan: Identifies areas of poor gas uptake

• Magnetic resonance imaging (MRI): Uses magnetic fields and radio waves

Medical and Surgical Procedures

Common Procedures

Medical and surgical procedures are used to treat respiratory diseases and manage airway function.

• Auscultation and percussion (A&P): Listening to breath sounds and tapping the back

• Cardiopulmonary resuscitation (CPR): Emergency procedure for cardiac and respiratory arrest

• Chest percussion therapy: Loosens mucus in the lungs

• Continuous positive airway pressure (CPAP): Treats sleep apnea

• Endotracheal intubation: Establishes airway with a tube

• Incentive spirometry: Encourages deep breathing post-surgery

• Nebulizer treatment: Delivers medication as a mist

• Oxygen therapy: Provides supplemental oxygen

• Bronchoscopy: Examines trachea and bronchi

• Chest tube insertion: Removes air, fluid, pus, or blood

• Lung resection: Removes part or all of a lung

• Thoracentesis: Removes pleural fluid

• Thoracotomy: Incision into thoracic cavity

• Tracheostomy: Provides access to lungs for respiratory support

Abbreviation Summary

Common Respiratory Abbreviations

Key Medical Terms and Definitions

• Bronchopulmonary: Refers to bronchi, bronchioles, and lungs

• Dyspnea: Difficult or labored breathing

• Apnea: Absence of breathing

• Tachypnea: Abnormally fast breathing

• Cyanosis: Bluish skin due to low oxygen

• Hemothorax: Blood in the thoracic cavity

• Pneumothorax: Air in the pleural space causing lung collapse

Summary Table: Respiratory Diseases