Lecture 9- Lung Defence I

Question 1

What cells make up the mucociliary escalator?

Answer 1

Ciliated airway epithelium

Question 2

What are the 2 layers of airway surface liquid?

Answer 2

Upper gel layer (mucins)

Peri-ciliary sol layer (liquid)

Question 3

At what thickness should the peri-ciliary sol layer remain at?

Answer 3

7 micrometers

Question 4

What causes absorption of the peri-ciliary sol layer fluid?

Answer 4

Sodium transport

Question 5

What causes fluid protection and secretion?

Answer 5

Chloride secretion

Question 6

What 2 innate defence molecules are found within the ASL

Answer 6

Defensins and opsonins

Question 7

What 3 scavenging innate cella are found in the ASL?

Answer 7

Alveolar macrophages, neutrophils and chronic inflammatory cells

Question 8

How many times per second do the cilia beat?

Answer 8

10-14 times per second

Question 9

What is the function of CFTR?

Answer 9

Maintenance of the surface liquid

Question 10

How does CFTR carry out its function?

Answer 10

Downregulates ENac preventing dehydration of the ASL

Question 11

What is the role of ENaC?

Answer 11

Absorption of sodium from ASL into the epithelial cells

Question 12

What is the relationship between CFTR channels and patients with cystic fibrosis?

Answer 12

They have abnormal CFTR channels, which don’t downregulate ENaC

• sodium moves into cells uninhibited and water follows
• ASL becomes thick and sticky