Respiratory Tract Infections – Part 1 (Vocabulary Flashcards)

A vocabulary-focused set of flashcards covering key terms, definitions, and concepts from the Respiratory Tract Infections notes.

Anatomy of the Respiratory Tract

Structures from the nasal cavity (including sinuses) through the larynx (upper tract) and from the trachea to the bronchi (lower tract).

Upper respiratory tract

Nose, nasal cavity, paranasal sinuses, nasopharynx, oropharynx, and larynx with the epiglottis.

Lower respiratory tract

Trachea, bronchi, and lungs; sites of gas exchange and typically more protected by defenses.

Nasal cavity

Air-entry space within the nose containing conchae and meatuses for filtration and humidification.

Nasopharynx

Upper part of the pharynx behind the nasal cavity; contains tonsillar tissue and Eustachian tube opening.

Oropharynx

Mid-pharynx behind the mouth; contains tonsillar tissue and is a conduit for air and secretions.

Larynx

Voice box; routes air to lower tract and helps protect the airway during swallowing.

Epiglottis

Flap that covers the glottis during swallowing to prevent aspiration.

Trachea

Windpipe from the larynx to the bronchi; reinforced by cartilage rings and lined with ciliated mucosa.

Bronchi

Major airways branching from the trachea into the lungs, distributing air to each lung.

Respiratory microbiome

Normal microbial community of the respiratory tract that defends against pathogens and primes immunity.

Bartlett Score

Assessment of sample quality to improve culture sensitivity and specificity for diagnosing pathogens.

Inhalation (route of infection)

Entry of pathogens into the respiratory tract via inhaled air.

Aspiration (route of infection)

Inhalation of oropharyngeal secretions or contents leading to infection.

Haematogenous spread

Pathogen spread to the respiratory tract via the bloodstream.

Protective factors against infection

Nasal hairs, mucus-covered surfaces, mucociliary escalator, alveolar macrophages, neutrophils, and antimicrobial factors.

Mucociliary escalator

Ciliated, mucus-covered lining that clears inhaled pathogens from the airways.

Alveolar macrophages

Immune cells in the alveoli that phagocytose inhaled pathogens.

Neutrophils

Circulating immune cells that migrate to infection sites and destroy bacteria.

Lysozyme

Antimicrobial enzyme in secretions that damages bacterial cell walls.

Lactoferrin

Iron-binding protein that inhibits bacterial growth by depriving microbes of iron.

Secretory IgA

Mucosal antibody that neutralizes pathogens and limits transmission at mucosal surfaces.

Pharyngitis

Inflammation of the pharynx causing sore throat; often viral but can be bacterial (e.g., GAS).

Rhinovirus

Common causative virus of upper respiratory tract infections and pharyngitis.

Group A Streptococcus (GAS)

Streptococcus pyogenes; a primary bacterial cause of pharyngitis with potential complications.

Neisseria gonorrhoeae

Bacterial cause of pharyngitis and other infections; transmitted sexually; may involve respiratory tract.

Corynebacterium diphtheriae

Bacterial cause of diphtheria; toxin-producing strains cause systemic disease.

Arcanobacterium haemolyticum

Bacterial agent that can cause pharyngitis, sometimes confused with GAS.

Diphtheria toxin

A toxin produced by toxigenic Corynebacterium diphtheriae causing tissue damage and systemic effects.

Elek test

Laboratory test to detect diphtheria toxin production by Corynebacterium diphtheriae.

Hoyles medium

Enriched medium containing cysteine, tellurite, and blood used to isolate diphtheria organisms.

Diphtheria antitoxin

Antibody-based therapy used to neutralize diphtheria toxin; administer promptly.

Sinusitis

Inflammation of one or more paranasal sinuses, often following a viral URI.

Mucormycosis

Severe fungal infection by Mucorales; usually in immunocompromised hosts; high mortality.

Mucormycosis laboratory diagnosis

Tissue biopsy with fungal microscopy and culture (Sabouraud agar) for identification.

Otitis media

Infection of the middle ear; common in children; often follows a viral URI.

Acute otitis media pathogens

Viruses (e.g., RSV, rhinovirus) and bacteria (Streptococcus pneumoniae, non-typeable H. influenzae, Moraxella catarrhalis).

Mastoiditis

Infection of the mastoid air cells, usually a complication of acute otitis media.

Epiglottitis

Swelling of the epiglottis causing airway obstruction; medical emergency.

Epiglottitis common etiologies

H. influenzae type b, Streptococcus pneumoniae, Streptococcus pyogenes, Staphylococcus aureus.

Third-generation cephalosporins

Antibiotics (e.g., ceftriaxone, cefotaxime) used for serious respiratory infections like epiglottitis.

Amoxicillin-clavulanate

Broad-spectrum antibiotic used for acute bacterial sinusitis when first-line therapy is insufficient.

Penicillin (treatment of diphtheria)

Antibiotic of choice for diphtheria; typically given with supportive care and antitoxin when indicated.