structure of airway Flashcards
what is hyperventilation
Excessive ventilation of the lungs atop of metabolic demand (results in reduced PCO2 - alkalosis)
more o2 less co2
what is tachypnoea
Abnormally fast breathing rate
tidal volume
normal amount Tidal volume is the amount of air that moves in or out of the lungs with each respiratory cycle
inspiratory reverse volume
The amount of extra air inhaled — above tidal volume — during a forceful breath in.
expiritory reserve volume
Your expiratory reserve volume is the amount of extra air — above anormal breath — exhaled during a forceful breath out. T
residual volume
is the amount of air that remains in a person’s lungs after fully exhaling.
functional residual capacity
expiritory reserve + residual volume
is the volume of air present in the lungs at the end of passive expiration
what is capacity
sum of 2 or more volumes
inspiriratory capacity
The maximum volume of air that can be inspired after reaching the end of a normal, quiet expiration. It is the sum of the TIDAL VOLUME and the INSPIRATORY RESERVE VOLUME.
vital capacity
) is the maximum amount of air a person can expel from the lungs after a maximum inhalation. It is equal to the sum of inspiratory reserve volume, tidal volume, and expiratory reserve volume
what is minute ventilation
Gas entering and leaving the lungs
how do you worl it out
tidal volume * breathing frequency
what is alveolar ventialtion
gas entering and leaving alveoli
How do you calculate alveolar ventilation
(tidal volume-dead space) * breathing rate
factors affecting lung volume and capacity
gender body size(height not weight) fitness (children of athletic parents have larger lungs) age disease
what are 2 dead spaces
conducting zone and non-perfused parenchyma
the conducting zone is equivalent to
anatomical dead space
how much space should non perfused parenchyma cells take up (aka alveolar dead space)
0mL
why are they dead space
no gas exchange occurs at those places
what is the anatomical and alveolar dead space termed as
physiological dead space
how can you increase the amount of dead space
anaesthetic circuit snorkeling
decrease
tracheostomy
cricothyrotomy
what is dead space
Dead space is unable to participate in gas exchange
how is the chest and lungs connected
The chest wall has a tendency to spring outwards, and the lung has a tendency to recoil inwards
what are the forces normally
These forces are in equilibrium at end-tidal expiration (functional residual capacity; FRC), which is the ‘neutral’ position of the intact chest.
what pressure changes causes inspiration
Inspiratory muscle effort + chest recoil > lung recoil
expiration
Chest recoil < lung recoil + expiratory muscle effort
what is the visceral pleura pressure
negative pressure
what is Negative pressure breathing
Palv is reduced below Patm
how is it caused to be negative
diaphragm pulling down and the ribcage out
what is Positive pressure breathing
Patm is increased above Palv
example of negative pressure breathing
normal brething
positive pressure breathing
resusitation
cpap machine
mechanical ventilation
what are transmural pressures
pressure across membrane
trans respiratory system pressure
describe sventilation
decrease alveolar pressure you creeate a negative value
so when it is not 0 air is flowing
what is the main driving force in ventilation
diaphragm pulling downwards
Pulmonary ventilation
ventilating entire airways
Alveolar ventilation
= ventilating alveoli
what is the pleural cavity
Pleural cavity is a partial vacuum
what does max ventilation
Maximum ventilation involves full inspiratory muscle recruitment (syringe and bucket handle movement)
dalton law
Pressure of a gas mixture is equal to the sum (Σ) of the partial pressures (P) of gases in that mixture
fick
Molecules diffuse from regions of high concentration to low concentration at a rate proportional to the concentration gradient (P1-P2), the exchange surface area (A) and the diffusion capacity (D) of the gas, and inversely proportional to the thickness of the exchange surface (T)
v(gas)= a/t * D * (p1-p2)
henry
At a constant temperature, the amount of a given gas that dissolves in a given type and volume of liquid is directly proportional to the partial pressure of that gas in equilibrium with that liquid
Boyle
At a constant temperature, the volume of a gas is inversely proportional to the pressure of that gas
charles
At a constant pressure, the volume of a gas is proportional to the temperature of that gas
what is the gas composition of a house fire
less 02
more c02
more co
in altidue
the composition is the same
but air is “thinner”
changes that occur as you pass down the respiratory tree
WARMED, HUMIDIFIED, SLOWED and MIXED as air passes down the respiratory tree
what happens after o2 binds to haemoglobin
conformational chnage
affinity of heamoglobon for o2 increase
positive co operation
what can bind in the middle
2 3 dpg
function
facilitates unloading
what type of protien is heamoglobin
allosteric
what are problems with pulse oximeters
they detect o2 binding not o2 concentration
need to know their heamoglobin
how do you shift the o2 dissocitation curve to the right
high temp acidosis (bohr effect) (co2 lactic acid) hypercapnia (high co2) more 2 3 DPG (basically exercise)
how to shift to the left
increase affinity less temp alkalosis hypocapnia less 2 3 dpg
how to get a downward shift
anaemia
Impaired oxygen-carrying
capacity
upward shift
Polycythaemia
Increased oxygen-carrying capacity
what is up or down shift all about
amount of red blood cell to carry o2
what is the down left shift
high HbCO
Decreased capacity
Increased affinity
Less o2 bind and less unloading
what is the difference in affinity of Foetal haemoglobin
Greater affinity than adult HbA to ‘extract’ oxygen from mothers blood in placenta
what is the affinity difference in myoglobin
Much much greater affinity than adult HbA to ‘extract’ oxygen from circulating blood and store it.
instead of deoxygenated what term should be used instead
mixed venous blood
how is carbon dioxide transported in blood
binds with h2o slowly to form
h2co3 (non enzymatically)
disscoiates into h+ and HCO3-
how can co2 be transported in the red blood cells
same reaction but cataylse of carbonic anhydrase
then hco3- moves out of rbc and chloride moves in
what is significant about the chloride shift
Negative chloride ions enter the RBC to maintain resting membrane potential
what transporter is involved
AE1 transporter
another method
can bind to heamoglobin
carbmenoheamoglobin
is gas exchnage faster for o2 or co2
co2
how does uncontrolled type 1 diabetes cause right shift
production of ketones
acidosis
why doesnt sunbathing cause right switch
because temp refers to temp of your muscles, humans can adapt to temp amd would sweat to combat
list all the diff ways o2 can be trasnported
O2 transported in solution (~2%) or bound to Hb (~98%)
list all diff ways co2 can be transported
CO2 transported in solution, as bicarbonate (HCO3-) and as carbamino compounds (e.g. HbCO2
feotal and myoglobin have a higher or. lower affinity for o2
Foetal Hb and myoglobin have a greater affinity for O2
is expiritory reserve
fake
is expiration greater than isnpiration
yep as tempreture increases
