Respiratory Pharmacology

Question 1

parasympathetic stimulation of post-ganglionic cholinergic fibres causes bronchiolar _______ and ______ mucus secretion on gland cells

Answer 1

contraction, increased (both these effects are mediated by M3 ACh receptors)

Question 2

sympathetic stimulation causes bronchiolar _____, ______ mucus secretion, _____ mucociliary clearance, and _____ vascular smooth muscle ____

Answer 2

dilation (via adrenaline from adrenal gland), decreased, increased, contraction (this contraction is mediated by a1 adrenoceptors, the rest are by B2)

Question 3

causes of asthma

Answer 3

exposure to allergens e.g. dust mites, dander, pollen, cold dry air

Question 4

asthma, and incidence

Answer 4

a recurrent and reversible obstruction to the airways in response to stimuli, affects 5-10% of people

Question 5

pathological changes that occur in chronic, poorly controlled asthma

Answer 5

• increased smooth muscle mass
• oedema
• increased mucus secretion
• epithelial damage (exposing sensory nerve endings)
• sub-epithelial fibrosis

Question 6

bronchial hyper-responsiveness in asthma

Answer 6

epithelial damage means that sensory nerve fibres are exposed, so sensitivity of airways to bronchoconstrictor is increased

Question 7

Smooth muscle relaxation is a result of…

Answer 7

dephosphorylation of MLC by myosin phosphatase

Question 8

Smooth muscle relaxation is a result of…

Answer 8

the rate of dephosphorylation of MLC by myosin phosphatase exceeding the rate of phosphorylation of MLC by MLCK. (This requires return of Ca2+ concentration to basal level, by primary and secondary transport).

Question 9

Adrenaline (transmitter from sympathetic ANS) _____ the activity of MLCK by phosphorylating it, and _____ the activity of myosin phosphatase by phosphorylating it

Answer 9

inhibits, stimulates (This is how salbutamol causes smooth muscle relaxation).

Question 10

in asthma, FEV1 is _____ and PEFR is _____

Answer 10

decreased, decreased

Question 11

what are the phases of an asthma attack?

Answer 11

1. Type I hypersensitivity reaction (bronchospasm and acute inflammation)
2. Type IV hypersensitivity reaction (bronchospasm and delayed inflammation)

Question 12

True/ False: Intrinsic asthma is triggered by factors related to allergies

Answer 12

False. Symptoms in this type of asthma are not associated to allergic reaction. No external cause can be identified.

Question 13

Non-atopic asthma produces low level Th1 response and involves macrophages and what type of antibody?

Answer 13

IgG

Question 14

Atopic asthma produces strong Th2 response and what type of antibody?

Answer 14

IgE

Question 15

Early exposure to microbes favours Th1/ Th2 response

Answer 15

Th1

Question 16

Hygienic “western” lifestyle favours atopic/ non-atopic asthma?

Answer 16

atopic

Question 17

Outline of development of allergic asthma?

Answer 17

1. Antigen presented to CD4+ by APC
2. Th0 mature to Th1 and Th2, but preferentially to Th2
3. Th2 produces cytokines which activate B cells, which produce plasma cells which secrete IgE
   4.

Question 18

Outline of development of allergic asthma?

Answer 18

1. Antigen presented to CD4+ by APC
2. Th0 mature to Th1 and Th2, but preferentially to Th2
3. Th2 produces cytokines which activate B cells, which produce plasma cells which secrete IgE, and cause eosinophils and mast cells to express IgE receptor
4. Subsequent antigen

Question 19

Outline of development of allergic asthma?

Answer 19

1. Antigen presented to CD4+ by APC
2. Th0 mature to Th1 and Th2, but preferentially to Th2
3. Th2 produces cytokines which activate B cells, which produce plasma cells which secrete IgE, and cause eosinophils and mast cells to express IgE receptor
4. Subsequent antigen presentation: cross-links IgE receptors, stimulatin Ca2+ entry into mast cells and release of intracellular Ca2+ stores, which evokes histamine and spasmogen release, and release of substances that attract cells causing inflammation