Blood and Lymphatics

Question 1

In a 70kg human, what percentage of their body is water?

How many litres is that?

Answer 1

60%

42 L

Question 2

In a 70kg human, 60% water, how much of this is INTRACELLULAR?

Answer 2

2/3 of 42 L = 28 L

Question 3

In a 70kg human, 60% water, how much of this is EXTRACELLULAR?

Answer 3

1/3 of 42 L = 14 L

Question 4

In a 70kg human, how many litres of INTERSTITIAL water do they have?

Answer 4

11 L

Question 5

In a 70kg human, what is their circulating blood volume?

How much of this is plasma and how much is red cells?

Answer 5

5 L

3 L plasma, 2 L red cells

Question 6

What is haematocrit?

What is the haematocrit value for males and females according to UHL?

Answer 6

Red blood cells

Males 40-54%

Females 37-47%

Question 7

What is the cardiac output at rest?

Answer 7

Rate x stroke volume

e.g. 70 bpm * 70 ml

= 4900 mls/min = 5 L/min

Question 8

How long does it take for the total blood volume to circulate once?

Answer 8

1 minute.