Respiratory disorders Flashcards
what does mucus in the nose do(2)
traps pathogens
protects olfactory neurons
where in the resp tract is there no mucus
alveoli
how does dust int eh alveoli get cleared up
patrolling macrophages
name a disease that is caught in mucus that doesn’t get destroyed by stomach acid
TB
why does gas exchange decrease in bacterial pneumonia
alveoli packed full of neutrophils
what is the relevance of the pleural seal
keeps intrapleural fluid in -> surface tension
what is the elastic recoil of teh chest?
outwards
what is the elastic recoil of the lungs
inwards
what is the relative pressure of the intrapleural space
slightly negative relative to atmospheric p
what is transpulmonary p. what type of value is it?
intrapulmonary p - interpleural p
always positive
what are teh two inversely proportional physical characteristics of lung tissue
compliance and elastance
elastance refers to RECOIL
what are teh two inversely proportional physical characteristics of lung tissue
compliance and elastance
elastance refers to RECOIL
what are the two types of pneumocytes
Type 1: gas exchange
Type 2: secrete surfactant
what does surfactant do
stops the alveoli sticking to themselves
how does surfactant work?
decrease water surface tension
what is the relative level of surfactant in larger/smaller alveoli
less/more
what is the net resistance in SMALL airways
it is (unintuitively) high, because they all run in parallel so actually more like one large vessel (think watering can)
do bronchioles have cartilaeg
no
how do bronchioles stay open
radial traction. The alveoli outside them pull/tether them open
in healthy lungs, how much alveolar dead space would you expect
around zero
how much of tidal vol is dead space
30%
how do you work out alveolar ventilation
(tidal vol-dead space vol) x resp rate
what are 5 signs of pneumothorax
tachycardia
tachypnoea
hyperresonance
absent breath sounds
hypotension (in tension pneumothorax)
what are 3 symptoms of pneumothorax
pain
dyspnoea
fatigue
what is interstitial disease
scar tissue between alveoli
what are 3 examples of interstitial disease
pulmonary fibrosis
restrictive pulmonary disease
asbestosis/silicosis
define restrictive v obstructive lung disease
restrictive = interstitial fibrotic - can’t get the air in - decreased compliance
obstructive = increased compliance, decreased elasticity, can’t get the air out
3 examples of obstructive diseases
asthma
COPD
bronchiostasis
what sort of mutation is CF
autosomal recessive
what does Boyle’s law say
pressure of gas is inversely related to the space it occupies
what is the name of the remaining air at the end of expiration
Functional Residual Capacity
what is a histological feature of small bronchi
cartilage plates (unlike big bronchi which have cartilage all round, and bronchioles which have no cartilage)
accessory muscles of inspiration
sternocleidomastoid
scalene
serratus
pectoralis major
accessory muslces of expiration
rectus abdominus
internal intercostals
where are the resp centres in the brain
medulla and pons
where is the automatic basal breathing rate set
Dorsal Resp Group - medulla
how does the VRG get activated
skeletal muscles send message asking for more oxygen
what does the VRG do?
stimulates accessory breathing muscles, also stimulates DRG to increase vent. rate
what are the other 2 resp centres
apneustic and pneumotaxic
what does Apneustic do
talks to DRG to decrease vent. rate
what does pneumotaxic c do?
talks to DRG to increase vent.
signs and symptoms fo interstitial lung disease
clubbing
dyspnoea on exertion progressing to at rest
dry cough
velcro lung crackles
smaller chest expansion on inspiration
name a hypoventilation acute condition
opiate overdose, head injury
name a chronic hypoventilation disease
muscular dystrophy, obesity, kyphoscoliosis
what is the cause of respiratory distress of the newborn
prem baby, not enough surfactant, alveoli stick together
label this
how long is FEV
1 sec
how long is FVC
6 sec
what should FEV/FVC be
> 0.7
what is PEF (peak flow rate)
where air is travelling fastest out of the lungs
what is DLCO
diffusing capacity of Carbon monoxide
what is DLCO
diffusing capacity of Carbon monoxide
what is chronic idiopathic pulmonary hypertension
hypertension in pulmonary arteries. Diet pills
