Lecture 1

Question 1

Give examples of respiratory diseases

Answer 1

Asthma, COPD, Influenza, CF and COVID-19

Question 2

Define aerosol

Answer 2

Relatively stable suspension of solid particles/liquid droplets in a gas

Question 3

Give examples of aerosols

Answer 3

Dust, smoke, fog and mist

Question 4

Define droplet transmission

Answer 4

Coughs or sneeze can spread droplets of saliva and mucus

Question 5

Define airborne transmission

Answer 5

Tiny particles possibly produced by talking are suspended in the air longer and travel further

Question 6

Advantages of systemic delivery for inhalation therapy

Answer 6

extensive blood supply and large SA => rapid drug absorption
avoids GI tract

Question 7

What controls aerosol behaviour?

Answer 7

movement of particles in the air is controlled by the interaction with other surrounding molecules and gravity

Question 8

What do aerodynamic properties depend on ?

Answer 8

Size, shape and density

Question 9

Name aerosol allergens

Answer 9

bacteria, viruses, smoke, tobacco smoke, household dust, coal dust

Question 10

Name the three particle deposition mechanisms

Answer 10

Inertial impaction (90%), Sedimentation (9%), Diffusion

Question 11

Describe inertial impaction

Answer 11

large, heavy particle breathed in quickly cannot turn quick enough so goes straight on and sticks to the back of the throat gets swallowed, dose not reach lungs

Question 12

Describe gravitational sedimentation

Answer 12

Occurs where air velocity is low in the RT so residence time is high therefore sedimentation builds up

Question 13

Describe diffusion deposition

Answer 13

Not influenced by gravity but influenced by the air molecules that are bombarding them from different random directions

Question 14

Define interception

Answer 14

Long fibrous particles deposit on contact with the walls as they can’t turn around the bend

Question 15

Define electrostatic deposition

Answer 15

Charged particles repel and increases migration towards airway walls and increased efficiency of deposition

Question 16

What factors affect aerosol deposition

Answer 16

aerosol properties (aerodynamic diameter, particle size distribution), mode of inhalation (flow rate, inhaled volume, breath holding pause), patient-related factors (anatomical and physiology variations, obstructive airways disease)