Question

Three factors that influence aerosol deposition in the lungs?

Answer 1

Aerosol deposition in the lungs is influenced by the size of airways, the presence of pulmonary surfactant, and the size of particulate matter. Narrow airways increase resistance, surfactant reduces alveolar surface tension, and smaller particles (PM10 and PM2.5) can penetrate deeper into the lungs.

Step-by-step explanation:

The deposition of aerosols in the lungs is influenced by several factors that affect respiratory health. Three such factors are:

The size of airways - Narrowing airways due to conditions like asthma can increase resistance and therefore influence the passage and deposition of aerosols.

The presence of pulmonary surfactant - Surfactant reduces surface tension within the alveoli, allowing easier expansion during inspiration and preventing the alveoli from collapsing during expiration, aiding in aerosol distribution.

Particle size - Especially particles known as PM10s (less than 10 micrometres) and PM2.5s (less than 2.5 micrometres), which can penetrate deeply into the lungs, potentially causing respiratory diseases.

Adequate airflow, healthy pulmonary surfactant levels, and the size of particulate matter in the air are crucial for understanding the factors that assist or hinder aerosol deposition in the lungs.

Answer 2

Aerosol deposition in the lungs is influenced by airway size, which affects resistance and air flow; surface tension in the alveoli, which is modulated by pulmonary surfactant; and particle size, with smaller particles penetrating further into the lungs.

Step-by-step explanation:

Factors Influencing Aerosol Deposition in the Lungs

There are multiple factors that affect the deposition of aerosols in the lungs, which can be significant for both medication delivery and the inhalation of pathogens or pollutants. Three such factors include:

1. Airway size: The diameter of the airways plays a pivotal role in the resistance to aerosol passage. A smaller airway diameter increases resistance and alters the path of aerosols, potentially leading to more deposition due to increased collisions with the airway walls.
2. Surface tension within the alveoli: This tension, caused by water in the alveolar lining, tends to inhibit alveolar expansion, influencing how particles deposit. However, pulmonary surfactant helps to reduce this tension, thus affecting deposition patterns.
3. Particle size: Aerosol particles that are less than 10 micrometres (PM10s) and particularly those less than 2.5 micrometres (PM2.5s) can penetrate deeply into the lungs. These fine particles are more likely to bypass the upper airway defenses and deposit within the alveoli.

Understanding these factors is critical for optimizing aerosol drug delivery systems and for implementing measures to protect against respiratory diseases caused by polluted air.