Blood

Question 1

How much blood does the average 70kg man hold?

Answer 1

5 litres.

Question 2

How is blood dispersed throughout the body?

Answer 2

1L lungs
3L systemic venous circulation
1L heart and arterial circulation

Question 3

What are the functions of blood?

Answer 3

Carriage of physiologically active compounds
Clotting 
Defence
Carriage of gas
Thermoregulation
Maintenance of ECF pH

Question 4

What is blood composed of?

Answer 4

Plasma
Red blood cells
White blood cells
Platelets

Question 5

What is the function of plasma?

Answer 5

Circulates biologically active molecules and proteins.

Question 6

What does plasma consist of?

Answer 6

Water, plasma proteins.

Question 7

Can plasma proteins cross the capillary wall?

Answer 7

Not usually.

Question 8

What are the most common plasma proteins?

Answer 8

Albumin
Globulin
Fibrinogen

Question 9

What does the inability of plasma proteins to permeate the capillary wall generate?

Answer 9

Colloid oncotic pressure.

Question 10

What forces is the net movement of fluid between a capillary and the interstitial space exposed to?

Answer 10

Capillary hydrostatic pressure

Plasma protein concentration

Question 11

What does capillary hydrostatic pressure favour?

Answer 11

Favours movement of fluid out of the capillary.

Question 12

What does plasma protein concentration favour?

Answer 12

Favours movement of fluid into capillary.

Question 13

What is hypoproteinaemia?

Answer 13

Condition in which the plasma protein concentration is too low.

Question 14

What condition occurs when the plasma protein concentration is too low?

Answer 14

Hypoproteinaemia.

Question 15

What is hypoproteinaemia characterised by?

Answer 15

Oedema due to loss of oncotic pressure and accumulation of fluid.

Question 16

What is the formation of blood cells called?

Answer 16

Haemopoiesis.

Question 17

What is haemopoiesis?

Answer 17

The formation of blood cells.

Question 18

What are blood cells derived from?

Answer 18

Haemopoietic stem cells.

Question 19

What are the types of blood cell?

Answer 19

Erythrocytes (RBC)
Leukocytes (WBC)
Platelets

Question 20

How are erythrocytes formed?

Answer 20

Erythropoiesis.

Question 21

What is erythropoiesis?

Answer 21

Formation of red blood cells.

Question 22

How are red blood cells characterised?

Answer 22

Small, biconcave shape, no nucleus- increases surface area for nutrient diffusion, red due to haemoglobin.

Question 23

What makes erythrocytes red?

Answer 23

Haemoglobin presence.

Question 24

What are the most abundant blood cell?

Answer 24

Erythrocytes.

Question 25

What is erythropoiesis controlled by?

Answer 25

Erythropoietin.

Question 26

What does erythropoietin do?

Answer 26

Catalyses the development of pluripotent stem cells into erythrocytes.

Question 27

When can erythropoietin concentration be increased?

Answer 27

When RBC are needed more- e.g. during haemorrhage, anaemia etc.

Question 28

What are leukocytes?

Answer 28

White blood cells.

Question 29

What are leukocytes involved in?

Answer 29

Immune response.

Question 30

How are leukocytes formed?

Answer 30

Leukopoiesis

Question 31

How are leukocytes characterised?

Answer 31

Larger cells, nucleated, pathogenic defence.

Question 32

Why is leukopoiesis more complex than erythropoiesis?

Answer 32

Involves a cocktail of cytokines.

Question 33

What do the cocktail of cytokines in leukopoiesis include?

Answer 33

Colony stimulating factor | Interleukins

Question 34

What do colony stimulating factors and interleukins feature in?

Answer 34

Cocktail of cytokines within leukopoiesis.

Question 35

Where are cytokines released from?

Answer 35

Endothelial cells Fibroblasts Mature WBC

Question 36

What does bacterial infection stimulate?

Answer 36

Increased production of neutrophils.

Question 37

What does viral infection stimulate?

Answer 37

Increased production of lymphocytes.

Question 38

Why is the cytokine cocktail in leukopoiesis described as dynamic?

Answer 38

It can be altered to produce certain types of cells during specific times of need (e.g. specific infections).

Question 39

What are platelets?

Answer 39

Membrane bound fragments derived from megakaryocytic.

Question 40

Are platelets nucleated?

Answer 40

Rarely.

Question 41

What is the formation of platelets governed by?

Answer 41

Thrombopoietin.

Question 42

What do platelets do in clotting?

Answer 42

Adhere to damaged cell endothelium and exposed connective tissue.

Question 43

Do platelets adhere to healthy cell endothelium?

Answer 43

No.

Question 44

What is the haematocrit?

Answer 44

The ratio of the RBC volume in comparison to the total volume of blood.

Question 45

What is the usual RBC percentage in the haematocrit?

Answer 45

40-50% - lower in women.

Question 46

When would the haematocrit differ?

Answer 46

Pathological conditions, anaemia, pregnancy etc.

Question 47

What is viscosity of blood?

Answer 47

Blood viscosity describes the thickness of blood in comparison to water.

Question 48

What does blood viscosity depend on?

Answer 48

Haematocrit Temperature Flow rate