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Anatomy & Physiology > Blood & Blood Groups > Flashcards

Flashcards in Blood & Blood Groups Deck (73):
0

What are the functions of blood?

Delivery of nutrients.
Transport of gases for gas exchange.
Transport of metabolic waste.
Carriage of hormones, enzymes, drugs and their metabolites.
Immunological role.
Thermoregulation.

1

Where in the body would you find the most blood at anytime?

Small veins & venules

2

Where in the body would you find the least amount of blood at anytime?

Capillaries

3

What type of tissue is blood?

Specialised connective tissue

4

What are bloods 2 components that make it a connective tissue?

Plasma (non-cellular matrix)
Blood cells (formed element)

5

Define haematocrit?

The fraction of the total blood volume that is occupied by the red cells.

6

How would you calculate a haematocrit?

Centrifuged blood sample

7

What is a normal haematocrit value?

35% - 50% (males upper end/ females lower end)

8

What effect would anaemia have on haematocrit values?

Lower than normal

9

What effect would polycythaemia have on haematocrit values?

Higher than normal

10

What does plasma contain?

90-95% water, 5-10% solutes

11

What is the pH of plasma?

7.35-7.45

12

What does plasmas solutes contain?

Salts (electrolytes) - sodium, potassium, calcium, chloride & bicarbonate

13

What products ate found in plasma?

Salts (electrolytes), glucose, amino acids, urea & other small molecules, hormones, plasma proteins (albumins, globulins, fibrinogen)

14

Name all 3 plasma proteins?

Albumins, globulins, fibrinogen

15

What are the functions of plasma proteins?

Own individual functions. Binding, clotting, antibodies.
Maintain fluid balance between plasma & interstial fluid.
Healthy correct level of plasma proteins in the capillary blood.

16

What is fluid removed from interstial space by?

Lymphatic drainage vessels

17

What happens if plasma protein levels low?

More fluid than normal leaves the blood the lymphatics are unable to carry all of this fluid away.

18

What is oedema?

The accumulation of excessive fluid in the tissues.

19

What are the clinical names for red & white blood cells & platelets?

Red cells- erythrocytes
White cells- leukocytes
Platelets- thrombocytes

20

What is the name of the stem cells in bone marrow that blood derives from?

Haemotopoietic tissue

21

How many red blood cells per litre are there in a healthy person?

4.5-6.5 million million per litre

22

What are the properties of red blood cells?

Biconcave disc, non-nucleated in adult form, no mitochondria, contain haemoglobin (Hb)

23

What are the properties of Hb?

Iron containing protein.
Binds avidly to oxygen to form oxyhaemoglobin.
Each Hb molecule can combine with 4 oxygen molecules.

24

What would oxygen saturation be if all 4 Hb molecules combined with 4 oxygen molecules?

100% saturation

25

What is a normal Hb concentration?

11-18g/100ml (dL) or 110-180g/ litre (may be less in pregnancy

26

What is the process of red blood cell formation called?

Erythropoiesis

27

What stimulates erythropoiesis?

Hormone called erythropoietin thats made in the kidneys.

28

Where is erythropoietin made?

Kidneys

29

What stimulates the secretion of erythropoietin?

Response to a fall in oxygen levels in arterial blood.

30

When might oxygen levels fall naturally in arterial blood?

High altitude

31

Why can red blood cells not divide?

Have no nucleus

32

How long do red blood cells live in the circulation?

Around 120 days

33

Where are red blood cells destroyed?

Spleen ( lesser extent in the liver or lymph nodes)

34

How many white blood cells are found in a healthy person?

4-10 thousand million per litre

35

How is white blood cell count reported?

Differential count ( different types if white blood cells are counted seperately)

36

How do white blood cells differ from red blood cells?

Slightly larger.
Nucleated.
Involved in defending against pathogens.

37

What type of whit blood cell is a phagocyte?

Neutrophils, Monocytes, Macrophages

38

What do basophils secrete?

Histamine

39

What other than being a phogocyte do macrophages secrete?

Pyrogens (heat)

40

What white blood cell is anti-parasitic & play a role in allergic reactions?

Eosinophils

41

What do natural killer cells secrete?

Cytotoxic chemicals

42

What are platelets?

Cell fragments derived from large cells (megakaryocytes) in the bone marrow.

43

How many platelets are found in the blood?

1.5 - 4.0 hundred thousand million per litre

44

How big is a platelet?

Around 2um in diameter - Irregular in shape.

45

What are platelets involved in?

Haemostasis (blood clotting)

46

What do platelets play a continuous role in maintaining?

Vessel integrity

47

What is haemostasis?

Blood clotting

48

What are the stepsof haemostasis?

Vasoconstriction
Platelets adhere to site of damage in blood vessel wall
Secrete chemicals that promote further platelet adhesion
Platelet plug is formed to stem the flow of blood
The clotting cascade is initiated
Once repaired- clot dissolved (fibrinolysis)

49

What is the process of a clot dissolving caused?

Fibrinolysis

50

What does an incompatible blood transfusion result in?

Agglutination, haemolysis, fever & jaundice

51

What are the antigens & antibodies in blood made from?

Protein

52

Where are antigens in blood found?

Red blood cells

53

Where are antibodies in blood found?

Plasma

54

How many major blood group systems are there?

Over 30

55

What is agglutination?

Clumping together of red blood cells that occurs as a result of an antigen -antibody reaction.

56

What causes agglutination?

Anti-a antibody binds to a -antigens (same with b)

57

What antigens and antibodies does blood group a contain?

A-antigen anti-b antibody

58

What antigens and antibodies does blood group b contain?

B-antigen & anti-a antobody

59

What antigen & antibody does blood group ab contain?

A & b antigen neither antibody

60

What antigen & antibody does blood group o contain?

Neither antigen & anti-a & anti-b antibodies

61

What process is used to ensure compatability of blood?

Cross matching

62

What canincompatible blood transfusions result in?

Agglutination, haemolysis & possibly death

63

What is the golden rule for blood transfusion in an emergency?

The recipients antibodies must not be able to agglutinate the donors red cells

64

What blood group is the universal donor?

Group o

65

What blood group is the universal recipient?

Group ab

66

What is rhesus status determined by?

Presence of Rh- or D- antigens on the persons red blood cells

67

What percentage of the population are Rh +?

85%

68

What do Rh- blood types not have?

Rh antigens

69

Where are anti-rhesus antibodies found?

Arise naturally in plasma

70

When can Rh- people develop a rhesus antigen?

If they come into contact with cells that posses the rhesus antigen

71

What is haemolytic disease of newborn?

Anti rhesus antibodies cross the placenta from mother to fetus & cause severe agglutination reaction

72

How can haemolytic disease of newborn be prevented?

Anti-d immunoglobulin ( coats fetal cells)