Respiratory System III Airflow and Airway Resistance

This set of flashcards covers key concepts from the lecture notes on the respiratory system, focusing on airflow, airway resistance, and related diseases.

What is the formula for airflow (Fa) in the respiratory system?

Fa = (Patm - Palv) / R, where R is airway resistance.

What characterizes airflow in large airways according to the mechanics of breathing?

Airflow tends to be turbulent in the trachea and large airways.

What does Poiseuille's Law state about the resistance to laminar flow?

Resistance is inversely proportional to the fourth power of the radius r (R ~ 1/r^4).

How does lung volume affect airway caliber and resistance during inspiration?

Increasing lung volume during inspiration increases airway diameter and decreases airway resistance.

What causes nasal airway obstruction in allergic rhinitis?

Histamine release, causing inflammation and fluid accumulation in the nose.

What are the two types of airway obstruction seen in obstructive pulmonary diseases?

Extrapulmonary obstruction (e.g., obstructive sleep apnea) and intrapulmonary obstruction (e.g., asthma, COPD).

How is airflow obstruction assessed in patients?

By dynamic spirometry, measuring FEV1, FVC and their ratio.

What is the role of beta-adrenergic agonists in asthma treatment?

They bind to beta-2 receptors and dilate bronchioles to prevent or inhibit asthma attacks.

What is a common symptom seen in croup among children aged 6 months to 3 years?

Seal-like barking cough and difficulty in breathing.

What are the chronic conditions characterized by airway resistance due to inflammation and narrowing?

Asthma, chronic bronchitis, and emphysema.