Resp summary 1 Flashcards
(15 cards)
Why is the respiratory tract highly susceptible to infection?
Due to continuous exposure to airborne pathogens; average person inhales 15,000L of air and 10,000 microbes daily.
Which parts of the respiratory tract are sterile?
The lower respiratory tract is typically sterile.
What are the key functions of the nasal mucosa?
Humidifies and filters air; lined with goblet cells and cilia to trap and remove particles.
What is the function of the turbinates?
Bony projections that create turbulent airflow, increasing mucosal contact for air filtration and conditioning.
What is mucociliary clearance and why is it important?
A defence mechanism moving mucus and trapped particles out of airways; impairment promotes infection and affects nasal drug delivery.
What is histamine and what roles does it play?
A monoamine derived from histidine; acts as a neurotransmitter and immune mediator.
What are the roles of histamine receptor subtypes?
H1: Inflammation, itching
H2: Gastric acid secretion
H3: Neurotransmission
H4: Immune cell chemotaxis
How does mast cell degranulation occur?
IgE binds to FcεRI → Re-exposure triggers degranulation via Lyn and Syk kinases → PLC activation → IP3 and DAG → Ca²⁺ release → Exocytosis of histamine
What are the clinical symptoms resulting from mast cell mediator effects?
Nerves: Itching, sneezing
Blood vessels: Redness
Endothelium: Swelling, rhinorrhoea
Nasal cavity: Congestion
Name common triggers of respiratory inflammation.
Viral infections (rhinovirus, influenza, RSV), allergens (pollen, dust mites), irritants (smoke, pollution)
What are key inflammatory mediators in the respiratory tract?
Histamine, leukotrienes, prostaglandins, cytokines (IL-6, IL-1, TNF-α)
What causes nasal congestion?
Vasodilation, increased permeability, goblet cell hyperactivity → swelling and mucus production
What are common causes of nasal congestion?
Viral URTIs and allergic rhinitis
Which receptors are targeted in treating nasal congestion?
α1-Adrenergic (vasoconstriction), H1 (antihistamines), Glucocorticoid (anti-inflammatory)
Summarise key immunological concepts in respiratory disease.
Histamine and mast cell activity drive symptoms; mucosal swelling and irritation stem from immune responses; understanding targets aids treatment.
