Oxygen in Blood

Question 1

where does myoglobin deliver oxygen

Answer 1

to muscles

Question 2

which has a higher affinity for oxygen; haemoglobin or myoglobin

Answer 2

myoglobin

Question 3

at what partial pressure is myoglobin fully saturated

Answer 3

5 kPa

Question 4

what are the 2 states of haemoglobin

Answer 4

1. T state

2. R state

Question 5

what is the T state of haemoglobin

Answer 5

where in low partial pressures of oxygen it is difficult for oxygen to bind to haemoglobin

Question 6

what is the R state of haemoglobin

Answer 6

where in high partial pressures of oxygen it is easy for oxygen to bind to haemoglobin

Question 7

what shape saturation curve does myoglobin give

Answer 7

hyperbolic

Question 8

what shape saturation curve does haemoglobin give

Answer 8

sigmoidal

Question 9

at what partial pressure is haemoglobin fully saturated

Answer 9

10 kPa

Question 10

why is the partial pressure of oxygen in tissues never 0

Answer 10

as then there wouldn’t a a partial pressure gradient so oxygen wouldn’t move into cells

Question 11

what is hypoxemia

Answer 11

low oxygen content in arterial blood

Question 12

what is hypoxia

Answer 12

low oxygen content in tissues

Question 13

give some examples of causes of hypoxia

Answer 13

shock - vasoconstriction means less blood is delivered to tissues so they receive less oxygen
peripheral arterial disease - less blood is delivered

Question 14

what is cyanosis

Answer 14

a blue discolouration due to the presence of unsaturated haemoglobin

Question 15

how does pulse oximetry work

Answer 15

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

Question 16

can pulse oximetry pick up carbon monoxide poisoning

Answer 16

no - as carboxyhemoglobin is bright red it will only show high saturation of haemoglobin

Question 17

from what artery is an arterial blood gas taken

Answer 17

radial artery

Question 18

what is the Bohr Curve

Answer 18

a shift to the right of the saturation curve due to the release of H+ ions giving a lower affinity of haemoglobin to oxygen

Question 19

why is the Bohr Curve advantageous

Answer 19

more oxygen is released to respiring cells

Question 20

what does an increase in temperature do to the saturation curve

Answer 20

shifts it to the right

Question 21

what does 2,3-BPG do to the saturation curve

Answer 21

shifts it right

Question 22

what does 2,3-BPG stand for

Answer 22

2,3-Bisphosphoglycerate

Question 23

what does carbon monoxide do to oxygen binding

Answer 23

means less oxygen binds as CO has a higher affinity for haemoglobin
prevents the oxygen already bound from dissociating