Mixed flashcards (lectures 1-8)
the lining of the respiratory tract is composed of what cell
pseudo-stratified ciliated columnar cells
what is the major determinant of airway resistance
radii of the airways
what does FRC stand for
functional residual capacity
what is the functional residual capacity
expiratory reserve volume + residual volume
what does the equation FEV1:FVC refer to
fraction of vital capacity expired in 1 second
if pressure in the intraplueral space was positive what would happen to the lungs
the lungs would collapse
why is the apex of the lung less compliant than the base
because the alveoli at the apex are more inflated at FRC therefore they aren’t completely empty when the next inhalation happens
the base of the lung is more compliant than the apex why is this
the weight of the top of the lung and the diaphragm at the bottom of the lung base, compress the alveoli at the base on the lung and this makes it more compliant on inspiration
what is the opposite of a shunt
alveoli dead space
without haemoglobin how much oxygen dissolves per liter of plasma
3ml/L
with the aid of haemoglobin how much oxygen dissolves per liter of plasma
200ml/L
92% of Hb of redblood cells is what type of Hb
HbA
8% of Hb of redblood cells is what type of Hb
HbA2
during hyperventilation what does PaO2 rise to and PaCO2 fall to
around 120mmHg for O2
around 20mmHg for Co2
during hypoventilation what does PaO2 fall to and PaCo2 rise to
PaO2 fall to around 30mmHg
PaCO2 rise to around 100mmHg
what percent of oxygen in the blood is extracted by tissues at rest
25%
at PaO2 of 60mmHg what percentage is haemoglobin saturated with oxygen
Hb is still 90% saturated at 60mmHg
at normal venous PaO2 (around 40mmHg) what percentage is Hb saturated with oxygen
Hb is still 75% saturated with oxygen
why does HbF have a higher affinity for oxygen than HbA
so it is able to extract oxygen from maternal arterial blood
when Co2 diffuses from the tissue into the blood 7% of it does what
remains dissolved in plasma and erythrocytes
when Co2 diffuses from the plasma to the blood 23% of it does what
combines in the erythrocytes with deoxyhemoglobin to form carbamino compounds
when Co2 diffuses from the plasma to the blood 70% of it does what
% combines in the erythrocytes with water to form carbonic acid, which then dissociates to yield bicarbonate and H+ ions
how is CO2 capable of changing ECF pH
CO2 + H2O ↔ H2CO3 ↔ HCO3 + H+
therfore H+ ions can affect the pH
what affect does hypoventilation have on blood pH
leads to decrease in pH and respiratory acidosis
