lectures 6 and 7: Haemoglobin and gas transport

Question 1

how much oxygen is in each litre of systemic arterial blood

Answer 1

200ml

Question 2

what is the major determinant of the degree to which haemoglobin is saturated with oxygen

Answer 2

partial pressure of oxygen in arterial blood

Question 3

At the normal systemic arterial Po2 of 100mmHg what is the saturation of Haemoglobin

Answer 3

almost 100 percent

Question 4

does foetal haemoglobin have a higher or lower affinity for o2 than HbA

Answer 4

higher, this is necessary for extracting o2 from maternal/arterial blood

Question 5

define Anaemia

Answer 5

any condition where the oxygen carrying capacity of the blood is compromised

Question 6

what are the conditions that facilitate the dissociation of oxygen from haemoglobin (aka the affinity of haemoglobin for oxygen is decreased)

Answer 6

decrease in pH
increase in Pco2
increase in temperature

Question 7

what are the conditions that make oxygen uploading more difficult but aid the collection of oxygen (aka the affinity of haemoglobin for oxygen is increased)

Answer 7

Increase in pH
decrease in Pco2
decrease in temperature

Question 8

what does the binding of 2,3-DPG to Hb do to its affinity for Oxygen

Answer 8

the affinity of Hb for oxygen is increase by the binding of 2,3-DPG

Question 9

when in 2,3-DPG synthesised

Answer 9

in situations with inadequate oxygen supply and helps maintain oxygen release in the tissues

Question 10

define hypoxia

Answer 10

deficiency of oxygen reaching the tissues

Question 11

define hypoxic hypoxia

Answer 11

most common- reduction in o2 diffusion at lungs

Question 12

define anaemic hypoxia

Answer 12

reduction in o2 carrying capacity of blood due to anaemia

Question 13

define Ischaemic hypoxia

Answer 13

heart disease results in inefficient pumping of blood to lungs/around the body

Question 14

define histotoxic hypoxia

Answer 14

poising prevents cells utilizing oxygen delivered to them for example carbon monoxide poising or cyanide

Question 15

define metabolic hypoxia

Answer 15

oxygen delivery to the tissues does not meet increased oxygen demand by cells

Question 16

during hypo-ventilation will you get an increase or decrease in H+ levels

Answer 16

increase as there is too much co2 in the blood aka respiratory acidosis

Question 17

during hyperventilation will you get an increase or decrease in H+ levels

Answer 17

decrease as there is less co2 in the blood aka respiratory alkosis