respiratory disorders - obstructive and restrictive Flashcards
what is the difference between obstructive and restircive lung diseases
O - difficulty getting air out of lungs, can result in r.acid
e.g. COPD, asthma
> FEV1:FEV is less than 70%
R- difficulty filling lungs with air as they are rigid +stiff e.g pulmonary fibrosis
> FEV:FEV1 is either normal or elevated
why does the left lung have only 2 lobes but the right has 3?
to make room for the heart!
name some lung cells
almost 58 types
most common is epithelial - gas exchange and barrier funtions
basal cells - stem cell of airway and differentiate to
cillia cells - help airway clearance and beat pathogens
gobet secreotry cells - secrete mucours to trap pathgoen and prtect airway
how can we measure lung functions?
use a spirometer which will give FEV, FEV1. FVC
use them to indicate if someone has an obstructive or restrictive lung disease
value adjusted accoring to age, weight and gender as lung function decreases with age
describe the strucutral airway remodeeling changes in COPD. what are the consequences?
increased mucous secretion and increased fribroblast activity
small airway firbrosis and emphysema + coughing up mucous promoting aleveli collapse, narrowing airway = obstruct
alveoli cannot be fixed as there is a stem cell loss (type1 alveolar stem cell)
descriebt the CELL changes in COPD
- basal stem cells become squamous so do not differentiate = impaired repair capacity of lungs
- excess in mucousal/goblet cells so there is a mucous overproduction
how does smoking promote COPD
smoking irritants activates cytokines which activate neutrophil
neutrophil activates fibroblasts = small airway fibrosis
also NEUTROPHIL ELASTASE expression increases, this is a protease that can degrade alveolar walls = emphesma
> NE inhibited by alpha antitrypisn so a deficiency can predispose to COPD
how can we diagnose COPD
use spirometry to look at the FEV1 - lower it is, the worse the disease progression
if fev1/fev less than 70% = obstructive
we can use computer chestomagraphy to detect evidence of emphesema
how can we treat COPD
use bronchodilators to relieve some symptoms
stop smoking
encourage a healthy active lifestyle
oxygen therapy/ pulmonary ventilator - risk of met.alk
lung surgery transplant to remove damaged tissue
what is key difference between atopic and non atopic asthma
atopic - allergenic response to external environment so elevated IgE levels
non-atopic - normal IgE level, more severe and later onset but rare
what actually happens in an asthma attack?/ airway remodelling
exposure to irritant (pollution, allergens, medications, virus) = airway inflammation
bronchiomembrane swells/smooth muscle thicc and the there is mucous hypersecretion due to goblet cell hyperplasia = narrowing of lumen
increases airway resistance, wheeze, cough, tight chest, shortness of breath
what is difference between asthma and COPD
asthma is reversible - this can be seen if we give a person a bronchiodilator and their FEV1 increases
What is R number?
represents the reproductive ability of avirus
if aboive 1 then an epidemic, below 1 can reverse it
covid has 1.5-3.5
