Introductory Weeks

Question 1

How many millilitres (ml) in 1 litre (L)?

Answer 1

1000 ml

Question 2

What is a decilitre (dl)?

Answer 2

1/10 of a litre

= 100 ml

Question 3

What is a millilitre (ml)?

Answer 3

1/1,000 of a litre

= 1 ml

Question 4

How much is a microlitre (µl)?

Answer 4

1/1,000,000 of a litre (1 µl)

Question 5

What is 1 ml equivalent to in ‘real life’ measurements?

Answer 5

20 drops of water

1/5 of a teaspoon

Question 6

How much is 5 ml in a teaspoon?

Answer 6

It is a full teaspoon

Question 7

How many grams (g) in a kilogram (kg)?

Answer 7

1000 g

Question 8

What is 1 gram (gm)?

Answer 8

1/1,000 of a kilogram

Question 9

What is 1 milligram (mg)?

Answer 9

1/1,000 of a gram

1/1,000,000 of a kilogram

Question 10

What is 1 microgram (µg)?

Answer 10

1/1,000,000 of a gram

1/1,000,000,000 of a kilogram!

Question 11

In the case of water, what does 1L equal in weight?

Answer 11

1 L = 1 Kg

Question 12

What are we measuring if we say we have 1 L of water?

Answer 12

Volume

Question 13

What are we measuring if we say we have 1 g of water?

Answer 13

Weight (mass)

Question 14

Order these from smallest to largest:

decilitre (dl), litre (L), microlitre (µl), millilitre (ml)

Answer 14

Microlitre = 1/1,000,000 of a litre (1 µl)
Millilitre = 1/1,000 of a litre (1 ml)
Decilitre = 1/10 of a litre (100 ml = 1 dl)
Litre = 1 L (1000 ml = 1 L)

Question 15

Order these from largest to smallest:

gram (g), kilogram (kg), microgram (µg), milligram (mg)

Answer 15

Kilogram = 1000 g (1000g = 1 kg)
Gram = 1/1,000 of a kilogram (1 g)
Milligram = 1/1,000,000 of a kilogram (1 mg)
Microgram = 1/1,000,000,000 of a kilogram (1 µg)

Question 16

If 1 L = 1 kg, then how much does 1 ml equal?

Answer 16

1 g

Question 17

What is the weight of the average adult male?

Answer 17

70 kg

Question 18

How much of the total body weight is made up of water, and therefore how many litres will that be equivalent to?

Answer 18

~ 60%

70 kg X 0.6 = 42 kg
= 42 L

Question 19

How is the total body water distributed to the intracellular and extracellular compartments, and what volumes do these equal to?

Answer 19

Of the 42 litres total body water:

1/3 is extracellular, which is 14 L
(42 L X (1/3) = 14 L)

2/3 is intracellular, which is 28 L
(42 L X (2/3) = 28 L)

(remember, 1 before 2, e before i)

Question 20

How is the extracellular water distributed?

Answer 20

~ 14 L extracellular water distributed into

11 L interstitial water
5 L circulating blood volume

Question 21

How much water is circulating blood volume in an average 70 kg male?

Answer 21

5 L

Question 22

How much of the circulating blood volume is plasma, and how much is red blood cells?

Answer 22

3 L = plasma
2 L = red blood cells

(to create 5 L circulating blood volume)

Question 23

What is haematocrit?

Answer 23

The proportion, by volume, of blood that consists of red blood cells

Question 24

What is required to collect blood for centrifugation?

Answer 24

10 ml (venous) blood in a test tube with one drop of EDTA (an anticoagulant).

Question 25

How does blood appear after centrifugation (sedimentation)?

Answer 25

A light (yellow) LIQUID layer appears on top - this is the PLASMA

Below that is a THIN LAYER/BUFFY COAT, which is made up of WHITE CELLS & PLATELETS (appears ‘white’)

At the bottom are the RED CELLS (appears red, or ‘dark’ red)

Question 26

How much of centrifuged blood is plasma, and how much is red cells?

Answer 26

60% plasma
40% red cells

(Which corresponds to 3 L plasma and 2 L red cells in 5 L circulating blood volume)

Question 27

What is the haematocrit levels for males following UHL guidelines?

Answer 27

40% - 54%

Question 28

What is the haematocrit levels for females following UHL guidelines?

Answer 28

37%-47%

Question 29

What is the normal haematocrit level (important!)?

Answer 29

2 litres in 5 litres, aka 40%

Question 30

What is the average resting heart rate?

Answer 30

70 beats per minute (bpm)

Question 31

What is the average stroke volume of the left ventricle, at rest?

Answer 31

70 ml/beat

Question 32

What is cardiac output?

Answer 32

Heart Rate x Stroke Volume

beats/min x L/beat = L/min

Question 33

What is the average resting cardiac output?

Answer 33

Cardiac Output (CO) = Heart Rate (HR) x Stroke Volume (SV)

At rest:
Heart Rate = 70 bpm
Stroke Volume = 70 ml/beat

So …
CO = 70 beats/min x 70 ml/beat
CO = 4900 ml/min

This rounds up to 5 L/min (learn!)

NB: CO will vary in individuals depending on many factors

Question 34

How many times does the total blood volume circulate per minute?

Answer 34

Once

Normal circulating blood volume = 5 L
Normal cardiac output = 5 L

So the total blood volume circulates once per minute

Question 35

Why might different sources on body fluid volumes be confusing?

Answer 35

The numbers are based on the AVERAGE 70kg individual - but as we know, humans tend to vary widely in real life!