Lung cell biology

Question 1

COPD consists of

Answer 1

Bronchitis
Small airways disease
Emphysema

Question 2

Epithelium functions

Answer 2

Continous barrier= isolates external environment from host
Secretions facilitate clearance
Metabolises foreign compounds
Mediator release
Lung repair process triggered

Question 3

Pathology of COPD

Answer 3

Increased globlet cell numbers
Increased mucus secretion (to deal with increase smoke)+ mucous= thicker
Less cilia than normal (more space taken up by goblet)= can’t clear mucous efficiently
Cilia beat asynchronously
Cilia found in bronchioles (move further down lung= blocks smaller airways)
Fibrosis= effort to repair damaged tissue= air can’t get through stenosis caused by fibrosis= small airways disease= COPD

Question 4

Consequence of COPD mucous

Answer 4

Thicker= traps smoke but also traps microorganisms= increased chance of infection (bronchitis)

Question 5

COPD alveolus compared to normal

Answer 5

Broken alveolar attachments= elastic tissue can’t pull on surroundings to keep it open
Excess mucus= blockage anyway

Question 6

Importance of lung lining liquid

Answer 6

Thin but imp for:
Surfactant= prevent alveolar collapse on expiration
Lung defense

Question 7

Club cells

Answer 7

Type of ciliated epithelial cell
Secretory
Detoxification
Repair cells
Lower in COPD

Question 8

Type of epithelial cells on alveolar surface
Type I= surface cover?
Type II= makes? stored? functions? quantity compared to T1?

Answer 8

Type I= thin, imp for gas exchange, solute transport, cover most of surface
Type II= makes surfactant stored in lameller bodies, precursor of Type I cells if Type I cell damage, detoxification, repair, double quantity than T1 but cover less surface

Question 9

Macrophages

Answer 9

Phagocytose particles

Either migrate into airways or cross membrane into lymph

Question 10

Stromal cells

Too many=?

Answer 10

Make extracellular matrix
Collagen, elastin= elasticity+ compliance
Repair
Too many= pulmonary fibrosis

Question 11

Alveolar fibrosis features
When does it happen
Why does it happen?

Answer 11

Increased type II cells (repair)
Increased fibroblasts
Increased collagen deposition

When type II doesn’t differentiate into type I properly= more fibrous tissue+ less exchange rate

Elevated growth factors

Question 12

Effect of cigarettes
Functions of cells involved?
Overload effect?

Answer 12

Blocks repair process of epithelium
Increased macrophages
Increased neutrophils

Phagocytosis, synthesise antioxidants, proteinases, activates pro-inflammatory mediators
Contain phase I+ II enzymes= xenobiotic metabolism (so do club cells+ type II cells)= water soluble+ excreted
Overload/ inactive enzyme=xenobiotic metabolism can’t occur on all of compound= DNA binding, no repair, mutation

Question 13

Secretory epithelial cells

Functions

Answer 13

Goblet
Club
Type II

Surfactant+ mucus= protective lining layer
Antioxidant release
Antiproteinases
Lysosymes= bacterial cell wall destruction
Xenobiotic metabolism (detoxify foreign compounds)