Ventilation and lung volume, gas transport... L5 Flashcards
ventilation=
movement of air into and out of the lungs
minute volume
volume of ai entering and leaving the lungs each minute
tidal volume
the volume of each breath
vital capacity (VC)
the volume of maximum expiration following maximum inspiration
how to calculate minute volume
respiratory rate x tidal volume
residual volume=
the air remaining in the lungs after a maximal expiration
why is alveolar ventilation less than pulmonary ventilation
because of dead space
how can be measure ventilation
spirometry
2 things that cannot be measured by spirometry
residual volume and functional residual capacity
what illness causes increased Residual volume
emphysema
FEV1=
forced expiratory volume in 1 second
what can be expressed as a percentage with FEV1
FEV1/ FVC (forced vital capacity)
PEFR=
peak expiratory flow rate
how to measure airway obstruction?
PEFR
what is the driving force of O2 into lungs and CO2 out
pressure gradient
Measure of O2 in the blood (bound to Hb and dissolved)
CaO2
Measure of O2 bound to Hb
SaO2
3 ways CO2 is carried in the blood
Dissolved
As HCO3- (70%)
As carbamino compounds
what is the formation of HCO3- increases by
carbonic anhydrase
where is carbonic anhydrase not present
plasma
structure of adult haemoglobin
2 alpha
2 beta chains
what shifts the O2 dissocation curve to the right
increased CO2
increase temp
increase BPG
Increased H+
what shifts the O2 dissocation curve to the left
decreased body temp
decreases CO2
increased pH
foetal Hb
what does hyperventilation cause
low CO2 (hypocapnia) and alkalosis
what does hypoventilation cause
high CO2 (hypercapnia) and acidosis
diabetic ketoacidosis–>
acidosis
renal failure–>
acidosis
Vomiting–>
alkalosis
dead space=
volume of lung not avalible for gas exchange
anatomical dead space
due to normal non- exchanging parts of airways (nasopharynx, trachea ect)
normal dead space
150ml
physiological dead space
volume of alveoli that receive air but insufficient blood supply
