Respiratory System and Related Disorders

Flashcards covering the functions, anatomy, diagnostic imaging, and diverse pathologies of the respiratory system as presented in the lecture notes.

Gas exchange

The primary function of the respiratory system that facilitates the transfer of oxygen and carbon dioxide between the body and the environment, occurring in the alveoli.

Mediastinum

The space between the lungs containing the heart, blood vessels, lymph nodes, nerve fibers, thymus gland, and esophagus.

Apex

The upper part of the lung that lies against the top of the thoracic cavity.

Base

The lower part of the lung that lies against the diaphragm.

Trachea

Also known as the windpipe, it is a continuous tube connecting the larynx to the major bronchi, held open by hyaline cartilage.

Carina

The last segment of the trachea where it divides to form the right and left main (primary) bronchi.

Bronchioles

The smallest of the conducting airways that branch from the bronchi.

Ciliary Blanket

A layer of mucus produced by epithelial cells in the conducting airways that traps dust, bacteria, and foreign particles.

Alveoli

Microscopic, cup-shaped, thin-walled air sacs of the respiratory tract surrounded by capillaries; there are approximately $300$ million in the adult lung.

Acinus

A term used to describe clusters of alveoli.

Hemoglobin

The main transporter of oxygen in the blood, carrying approximately $98\%$ of total oxygen.

Respiratory center

A collection of neurons located in the pons and medulla of the brain that integrates the control of ventilation.

Parietal pleura

The outer layer of the double-layered serous membrane that lines the pulmonary cavities and adheres to the thoracic wall, mediastinum, and diaphragm.

Visceral pleura

The inner layer of the double-layered serous membrane that closely covers the lung and is adherent to all its surfaces.

Pleural Cavity

A thin, fluid-filled potential space between the visceral and parietal pleura that allows for friction-free breathing and maintains pressure for lung expansion.

Pleural Effusion

An abnormal collection of fluid or exudate within the pleural cavity.

Endotracheal Tube (ETT)

A hollow plastic tube inserted into the trachea to ensure an open airway and facilitate mechanical ventilation.

Cuff

An inflatable balloon at the distal end of an ETT that produces a seal against the tracheal wall to prevent gastric aspiration and facilitate positive pressure ventilation.

Central Venous Catheters (CVC)

Also known as Central Venous Lines (CVL), these are catheters whose distal tips lie in a central vein, used for chemotherapy, fluid therapy, or parenteral nutrition.

Transvenous Cardiac Pacemaker

An artificial pacing device that delivers electrical impulses to the heart through electrodes threaded through a central vein into the right atrium or ventricle.

Cystic Fibrosis (CF)

A chronic genetic disorder caused by mutations in the CFTR gene leading to thick mucus accumulation, organ dysfunction, and electrolyte imbalances.

Hyaline Membrane Disease

Also known as Idiopathic Respiratory Distress Syndrome (IRDS), a condition in preterm neonates resulting from insufficient production of surfactant.

Surfactant

A mixture of lipids, proteins, and carbohydrates that decreases surface tension in the alveoli to prevent their collapse.

Croup

A common childhood respiratory illness affecting the trachea, larynx, and bronchi, characterized by inspiratory stridor and a barking cough.

Epiglottitis

Also known as Supraglottitis, a rare life-threatening condition caused by inflammation of the epiglottis that can lead to acute airway obstruction.

Thumb sign

The radiographic manifestation of an edematous and enlarged epiglottis seen on a lateral soft tissue radiograph of the neck.

Pneumonia

An infection of the lung involving the alveolar space that causes inflammation, most commonly caused by bacteria or viruses.

Interstitial Pneumonia

Lung inflammation predominantly affecting the walls and lining of the alveoli and interstitial supporting structures, often appearing as a linear or reticular pattern on X-ray.

Lung Abscess

A localized collection of pus within the lung parenchyma, forming a cavity filled with necrotic debris or fluid due to infection.

Tuberculosis (TB)

A preventable infectious disease caused by Mycobacterium tuberculosis, characterized by necrotizing granulomatous inflammation.

Miliary TB

A severe and disseminated form of tuberculosis where bacteria spread through the bloodstream to multiple organs, appearing as discrete nodules on a chest radiograph.

Tuberculoma

Also known as Tuberculous Granulomas, these are well-defined focal masses resulting from tuberculosis infection, most commonly occurring in the brain and lungs.

Pulmonary Mycosis

Lung infections caused by various fungi, such as Histoplasmosis or Aspergillosis, which are typically inhaled from the environment.

Aspergilloma

A fungal mass that appears as a well-demarcated, round, soft tissue mass located within a pre-existing air space cavity in the lung.

Pneumocystitis Jiroveci Pneumonia

A serious opportunistic fungal infection that commonly affects immunocompromised patients, particularly those with AIDS.

Chronic Obstructive Pulmonary Disease (COPD)

A treatable lung disease characterized by progressive airflow limitation and chronic inflammation, coexisting as chronic bronchitis and emphysema.

Chronic Bronchitis

A condition characterized by a persistent productive cough lasting at least $3$ months per year for $2$ consecutive years.

Emphysema

A progressive form of COPD involving the destruction of alveolar walls and air trapping, which can lead to large air-filled sacs called bullae.

Asthma

A chronic inflammatory condition characterized by bronchial hyperresponsiveness, mucous membrane swelling, and excess mucus secretion leading to intermittent airflow obstruction.

Bronchiectasis

A chronic lung disease involving permanent widening of the bronchi resulting from the destruction of the elastic and muscular components of the bronchial wall.

Signet-ring sign

The hallmark CT sign of bronchiectasis, characterized by multiple dilated bronchi.

Sarcoidosis

A multisystem disorder of unknown etiology characterized by noncaseating granulomas, typically presenting with bilateral hilar lymphadenopathy.

Donut sign

A CT finding in sarcoidosis where lymphadenopathy encircles the trachea.

Pneumoconiosis

A group of occupational diseases caused by the accumulation of fine inhaled particles that cause chronic interstitial inflammation and pulmonary fibrosis.

Silicosis

The world's most prevalent occupational lung disease, caused by the inhalation of silicon dioxide (crystalline silica).

Asbestosis

A chronic progressive interstitial lung disease caused by inhaling asbestos fibers, marked by pleural thickening and calcified pleural plaques.

Anthracosis

Also known as Black Lung Disease, an occupational lung disease caused by overexposure to coal mine dust.

Solitary Pulmonary Nodule (SPN)

A round or oval area in the lung smaller than $3\,cm$ ($1.2\,inches$) that is often discovered incidentally.

Small Cell Lung Cancer (SCLC)

Also known as Oat Cell Carcinoma, an aggressive malignancy originating from pulmonary neuroendocrine cells with high metastatic potential.

Adenocarcinoma

The most common primary lung cancer in the United States, evolving from mucosal glands and often found in the lung periphery.

Pulmonary Embolism (PE)

The obstruction of pulmonary arteries by a blood clot that has traveled from another area of the body, commonly originating as deep vein thrombosis (DVT).

Pulmonary Arteriovenous Fistula

Also known as Pulmonary Arteriovenous Malformation (PAVM), a rare vascular anomaly consisting of an abnormal communication between a pulmonary artery and vein.

Atelectasis

Partial or complete collapse of the lung or a section of the lung, often occurring postoperatively or due to airway obstruction.

Acute Respiratory Distress Syndrome (ARDS)

A life-threatening condition involving non-compliant lungs and poor oxygenation, associated with capillary endothelial injury and leakage of fluid into alveoli.

Mediastinal Emphysema (Pneumomediastinum)

The presence of air in the mediastinum, often developing when air extravasates from the airways, lungs, or esophagus.

Spinnaker sign

A radiographic finding of pneumomediastinum in pediatric patients where air elevates the thymus.

Subcutaneous Emphysema

The infiltration of air into the subcutaneous layer of skin, characterized by a crackling sound called crepitation on palpation.

Pneumothorax

The accumulation of air between the parietal and visceral pleurae, which can apply pressure on the lung and cause it to collapse.

Empyema

The presence of purulent fluid (pus) in the pleural space, often a complication of bacterial pneumonia.

Diaphragmatic Paralysis

A condition where one or both sides of the diaphragm lose the ability to contract due to muscular issues or loss of phrenic nerve innervation.

Eventration of the Diaphragm

A localized elevation or bulging of the hemidiaphragm without a break in continuity, caused by a lack of muscle or nerve function.