ventilation and compliance Flashcards
what is the anatomical dead space volume?
150ml
what is the partial pressure
the pressure of a gas in a mixture of gases is equivalent to the percentage of that particular gas in the entire mixture multiplied by the pressure of the whole gaseous mixture
what is the order of volumes starting with the nearest to the dead space?
residual expiratory reserve tidal inspiratory reserve RETI
whats the volume of the anatomical dead space?
150ml
what is the anatomical dead space
the volume of gas occupied by the conducting airways
is the anatomical dead space gas available for for exchange?
no
slide 5, learn those mf lung volumes and capacities
rip
what does the term ‘ventilation’ refer to?
movement of air in and out lungs
what are the two types of ventilation
pulmonary and alveolar ventilation
what is pulmonary ventilation
total air movement in and out of lungs
what is alveolar ventilation
fresh air getting to alveoli and therefore available for gas exchange
how much does an average human inhale and exhale?
500ml
what happens at the end of expiration
dead space filled with stale air from alveoli
what hhappens at end of inspiration?
dead space filled with fresh air
what is daltons law?
total pressure of a gas mixture is the sum of the pressure of the individual gases
what is partial pressure?
The pressure of a gas in a mixture of gases is equivalent to the percentage of that particular gas in the entire mixture multiplied by the pressure of the whole gaseous mixture
what is pressure expressed in?
mmHg or kPa units
what happens to P02 and Pc02 during hyper-ventilation?
Po2 rises (120) Pc02 falls (20)
what happens to P02 and Pc02 during hypo-ventilation?
P02 falls (30) Pc02 rises (100)
what is surfactant?
detergent like fluid
what produces surfactant
type 2 alveolar cells
what is the function of type 1 cells
permit gas exchange
what is the function of type 2 cells
secrete surfactant fluid
whats the function of surfactatnt
Reduces surface tension on alveolar surface membrane thus reducing tendency for alveoli to collapse
when does surface tension occur
where ever there is an air-water interface and refers to the attraction between water molecules
whats the definition of compliance
change in volume relative to change in pressure
what is high complaince
large increase in lung volume for small decrease in ip pressure
true or false
expiration is passive
true
whats Emphysema
loss of elastic tissue means expiration requires effort
Fibrosis
inert fibrous tissue means effort of inspiration increases
true or false
Alveolar ventilation declines with height from base to apex.
true
does compliance incline or decline with height from base to apex
decline
whats the difference between obstructive and restrictive lung disease?
obstructive - obstruction of air flow especiallion on expiration
restrictive- restriction of lung expansion
what is COPD
Chronic bronchitis - Inflammation of the bronchi
Emphysema -Destruction of the alveoli, loss of elasticity
what is spirometry?
technique used to measure lung function
what are the 2 classes of measurements of lung function
static and dynamic
what is a static lung function
where the only consideration made is the volume exhaled
what is the dynamic lung function
where the time taken to exhale a certain volume is what is being measured
whats a form of restrictive lung disease?
pulmonary fibrosis
what is the normal volume of alveolar ventilation?
4.2 litres
when is a person hypoventilating?
when they have less than 4.2 alveolar ventilation, quick af breathes
when is a person hyperventilatoing
when they have more than 4.2 alveolar ventilation, long ass breathes
what is the effect of fibrosis?
effort of inspiration increases
what is the effect of emphysema?
expiration requires effort
list some restrictive lung diseases? (4)
fibrosis
infant respiratory distress syndrome
oedema
pneumothorax
what should the volume of force expirated in 1 second in a healthy male?
4 litres
what should the volume of forced vital capacity in a healthy male?
5 litres
what is the effect of COPD
rate at which air is inhaled is much lower
total expired volume is reduced
what is the effect of pulmonary fibrosis
absolutew rate of airflow is reduced
total volume is reduced due to limitations to lung expansion
why dont type 2 cells permit gas exchange?
walls are too thick
why is surfacant helpful?
reduces attraction of water to eachother and reduces surface tension therefore stops alveoli from collapsing
why is surfactant more effective in small alveoli than large?
surfactant molecules come closer together and are therefore more concentrated.
is pressure greater in smaller or larger alveoli?
smaller alveoli
why do we want more smaller alveoli?
less surface area
how do you eqqualise the pressure in alveoli and prevent it from collapsing?
surfactant
why are babies susceptible to infant rest distress syndrome?
surfactant production doesnt start till 25 weeks and is only completed at 36 weeks.
whats the term used for the stretchability of the lungs?
compliance
is high compliance healthy lungs or poor lungs?
healthy lungs
is low compliance ever good?
no
what is low compliance
small increase in lung volume for large decrease in ip pressure
when is high compliance bad?
if it doesnt come with high elasticity
is volume in the lungs effected by gravity?
yes
whats an example of obstructive lung disorders
COPD
what are two types of COPD
chronic bronchitis and emphysema
what effects do loss of compliance have?
lung stiffness and incomplete lung expansion
what can spirometer not measure?
residual volume
is the forced exp volume in 1 second lower in obstructive or restrictive
obstructive
if you have a normal ratio does it always mean you have healthy lungs?
no, it could be restrictive lung disease and could have lower absolute numbers
