lung structure and airway diseases

Question 1

What does the respiratory tract consist of?

Answer 1

nasal cavity and sinuses
larynx
trachea
bronchi
bronchioles
alveolar duct
alveoli

Question 2

What does the conducting airways consist of?

Answer 2

trachea
primary bronchus
secondary bronchus

Question 3

What does the resistance airways consist of?

Answer 3

bronchiole
terminal bronchiole
respiratory bronchiole

Question 4

What does the respiratory airways consist of?

Answer 4

alveolar duct
alveolar sac

Question 5

The bronchus is covered in…?

Answer 5

smooth muscle and elastic fibres

Question 6

What lines the bronchus and bronchiole?

Answer 6

epithelium

Question 7

What is the role of the pulmonary arteries and veins?

Answer 7

carry blood to (arteries) and from (veins) the lungs

Question 8

Does the pulmonary veins carry O2?

Answer 8

yes

Question 9

Does the pulmonary arteries carry CO2?

Answer 9

yes

Question 10

What is the role of the bronchial arteries and veins?

Answer 10

supply blood to and drain from the airways

Question 11

Do bronchial arteries carry O2?

Answer 11

yes

Question 12

Do bronchial veins carry CO2?

Answer 12

yes

Question 13

What type of epithelium lines the airway?

Answer 13

pseudostratified columnar

Question 14

What is the role of the epithelium?

Answer 14

physical barrier (inhibits and prevents)
housekeeping role (ciliate cells)
catabolic metabolism (via cytochrome P450)
anabolic metabolism (synthesis of inhibitory mediators - PGE2)

Question 15

What are the main nerve types?

Answer 15

cholinergic (excitatory)
noradrenergic (inhibitory)
inhibitory nonadrenergic noncholinergic (iNANC)
excitatory nonadrenergic noncholinergic (eNANC)

Question 16

What role does the cholinergic nerves play?

Answer 16

major role in regulating airway smooth muscle tone and mucus production

Question 17

What is the major role of iNANC?

Answer 17

release nitric oxide
innervates smooth muscle directly
relaxation

Question 18

What is the role of eNANC?

Answer 18

release neuropeptides
increase airway tone, secretion of mucus and microvascular leakage

Question 19

What is asthma?

Answer 19

chronic inflammatory disease of the airways characterised by bronchial obstruction and airflow limitation

Question 20

Can bronchial obstruction and airflow limitation be reversible?

Answer 20

yes, either spontaneously or with treatment

Question 21

What are the characteristics of asthma?

Answer 21

shortness of breath
wheeze
tight chest
cough

Question 22

What are the two phases of the allergic response?

Answer 22

early phase response
late phase response

Question 23

What happens during the early phase of an allergic response?

Answer 23

decrease in FEV1, peak at 30-40 minutes, resolved in 2-3 hours
mast cell-derived histamine and leukotrienes

Question 24

What happens in the late phase of an allergic response?

Answer 24

release of inflammatory mediators cause submucosal oedema, airway wall swelling, secretion of mucus
epithelium remodelling, airway muscle hypertrophy/hyperplasia, subepithelial fibrosis

Question 25

What is FEV1?

Answer 25

the amount of air forced from lungs in 1 second

Question 26

What are the major characteristic features of asthma?

Answer 26

reversible bronchial obstruction airway hyperresponsiveness airway wall remodelling

Question 27

What is bronchial obstruction in asthma caused by?

Answer 27

a range of endogenous mediators

Question 28

What happens during bronchial obstruction?

Answer 28

increase airway smooth muscle tone; secretion of mucus shedding of epithelium and accumulation of debris oedema and selling of submucosa airway smooth muscle hypertrophy + hyperplasia sub-epithelial fibrosis

Question 29

What causes airway hyperresponsiveness?

Answer 29

a range of unrelated stimuli - methacholine, histamine, cold air

Question 30

What is the rule for airway resistance?

Answer 30

resistance to airflow is inversely proportional to the radius of the lumen raised to the fourth power

Question 31

What happens during airway hyperresponsiveness?

Answer 31

airway resistance airway narrowing

Question 32

What happens during airway remodelling?

Answer 32

1. dilated blood vessels 2. infiltration of inflammatory cells - eosinophil; mast cell; mononuclear 3. destroyed epithelium cells 4. thickened basement membrane 5. mucus plug with eosinophil and desquamated epithelial cells 6. hypertrophied smooth muscle

Question 33

Where is histamine stored?

Answer 33

in mast cells and basophils

Question 34

When is histamine released?

Answer 34

in early phase response

Question 35

What can histamine cause?

Answer 35

bronchoconstriction, airway wall oedema

Question 36

What are the major histamine receptor antagonists?

Answer 36

H1 and H4

Question 37

What is H1 receptor?

Answer 37

seasonal allergies not useful in asthma

Question 38

What is H4 receptor?

Answer 38

asthma, atopic dermatitis, psoriasis

Question 39

When is leukotrienes released?

Answer 39

early and late phase response

Question 40

What is LTB4?

Answer 40

chemoattractant for inflammatory cells

Question 41

What is LTC4, LTD4, LTE4?

Answer 41

potent bronchoconstrictors cause secretion of mucus induce release of chemical mediators from inflammatory cells

Question 42

What is COPD?

Answer 42

chronic obstructive pulmonary disease

Question 43

What makes up COPD?

Answer 43

chronic bronchitis + emphysema

Question 44

What are some primary causes of COPD?

Answer 44

tobacco smoking air pollution

Question 45

What is a treatment of COPD?

Answer 45

ipratropium bromide (muscarinic antagonist) + salbutamol (β2-adrenoceptor agonist)

Question 46

What are the features of chronic bronchitis?

Answer 46

inflammatory disease with irreversible airflow limitation hypersecretion of bronchial mucus secondary respiratory infections

Question 47

What types of drugs provide symptom relief for chronic bronchitis?

Answer 47

β2-adrenoceptor agonists muscarinic antagonist glucocorticoids mucokinetic drugs antibiotics

Question 48

What is another way to treat chronic bronchitis?

Answer 48

selective phosphodiesterase IV inhibitors (roflumilast)

Question 49

How does selective phosphodiesterase IV inhibitors help?

Answer 49

improves lung functions decrease freq. of exacerbations targets underlying inflammation