Oxygen in Blood Flashcards
where does myoglobin deliver oxygen
to muscles
which has a higher affinity for oxygen; haemoglobin or myoglobin
myoglobin
at what partial pressure is myoglobin fully saturated
5 kPa
what are the 2 states of haemoglobin
- T state
2. R state
what is the T state of haemoglobin
where in low partial pressures of oxygen it is difficult for oxygen to bind to haemoglobin
what is the R state of haemoglobin
where in high partial pressures of oxygen it is easy for oxygen to bind to haemoglobin
what shape saturation curve does myoglobin give
hyperbolic
what shape saturation curve does haemoglobin give
sigmoidal
at what partial pressure is haemoglobin fully saturated
10 kPa
why is the partial pressure of oxygen in tissues never 0
as then there wouldn’t a a partial pressure gradient so oxygen wouldn’t move into cells
what is hypoxemia
low oxygen content in arterial blood
what is hypoxia
low oxygen content in tissues
give some examples of causes of hypoxia
shock - vasoconstriction means less blood is delivered to tissues so they receive less oxygen
peripheral arterial disease - less blood is delivered
what is cyanosis
a blue discolouration due to the presence of unsaturated haemoglobin
how does pulse oximetry work
red light is emitted and the absorption of the red light is recorded
saturated haemoglobin is bright red so won’t absorb this light - therefore the more red light recorded/the less absorbed the more saturated the haemoglobin are
can pulse oximetry pick up carbon monoxide poisoning
no - as carboxyhemoglobin is bright red it will only show high saturation of haemoglobin
from what artery is an arterial blood gas taken
radial artery
what is the Bohr Curve
a shift to the right of the saturation curve due to the release of H+ ions giving a lower affinity of haemoglobin to oxygen
why is the Bohr Curve advantageous
more oxygen is released to respiring cells
what does an increase in temperature do to the saturation curve
shifts it to the right
what does 2,3-BPG do to the saturation curve
shifts it right
what does 2,3-BPG stand for
2,3-Bisphosphoglycerate
what does carbon monoxide do to oxygen binding
means less oxygen binds as CO has a higher affinity for haemoglobin
prevents the oxygen already bound from dissociating
