Physio - Blood Flashcards
What are the main functions of the blood
Transport i.e. gases, hormones, etc
Regulation i.e. pH, water balance, etc
Protection i.e. white blood cells, clotting, etc
How much blood does the average male have
5-6 litres
How much blood does the average female have
4-5 litres
What is the temperature of blood
37-38°C
What is the composition of blood
~55% plasma
~45% erythrocytes (red blood)
< 1% white blood cells and platelets
How many red blood cells are in the average adult
25 trillion
How many red blood cells does the body produce per second
2 million
How many O2 molecules can bind to one haemoglobin molecule
4
How many haemoglobin molecules in one red blood cell
250 million
What is the composition of plasma
90% water
8% plasma proteins
2% hormones/others
What is haematocrit
the ratio of the volume of red blood cells to the total volume
An expected value of haematocrit
F 37-47%
M 42-52%
What is an expected value of %SpO2
> 95%
What happens to haemoglobin when O2 binds to it
It changes the shape of the molecule and makes it easier for subsequent O2 to bind to it
high oxygen affinity
What is the effect of pH on oxygen affinity, the Bohr effect
High pH - high oxygen affinity - easier to remain in the R-state
Low pH - low oxygen affinity - easier to remain in the T-state
T-state
No oxygen bonded to haemoglobin, low oxygen affinity
R-state
All oxygen is bonded to haemoglobin, high oxygen affinity
What is the effect of temperature on oxygen affinity
High temp - low oxygen affinity - easier to remain in the T-state
Low temp - high oxygen affinity - easier to remain in the R-state
What is the effect of CO2 on blood pH and oxygen affinity
CO2 lowers pH, acidic, therefore oxygen affinity is reduced
How much CO2 is transported through the plasma
5-10%
How much CO2 is transported through haemoglobin
20-30%
How much CO2 is transported as bicarbonate ions
60-70%
Describe the Haldane effect
The change of CO2 capacity due to changes of oxygen pressure
Low O2 pressure - high CO2 affinity
High O2 pressure - low CO2 affinity
Arterial blood O2%
20mL/100mL
Venous blood O2%
5mL/100mL
What is arteriovenous blood difference
The difference in oxygen concentration between arterial and venous blood
Detail the effect of exercise on the value of a-vO2
During exercise, oxygen demands increase, which lowers O2 concentration in venous blood, therefore increasing a-vO2 difference
Is a-vO2 difference higher of lower in trained individuals
Higher
An increase in temp and decrease in blood pH would result in a _____ in the oxyhaemoglobin dissociation curve
Rightward shift
Lower oxygen affinity
