Blood Flashcards
(91 cards)
1
Q
blood general composition
A
45% cellular, 55% fluid
2
Q
Average amount of blood
A
5L
3
Q
Haematocrit definition
A
ratio of volume of RBC in blood
4
Q
what is normal haematocrit
A
0.45
5
Q
What is haemopoiesis
A
Process of production of RBC and platelets
6
Q
where does haemopoiesis occur in adults
A
bone marrow
7
Q
describe RBC in bone marrow in adults
A
nucleated
8
Q
describe RBC in peripheral blood in adults
A
anucleate
9
Q
where are precursor blood cells found in foetus
A
yolk sac, liver, spleen, bone marrow
10
Q
where are precursor blood cells found in children
A
all bones
11
Q
where are precursor blood cells found in adults
A
axial bone marrow
12
Q
what is the name given for formation of RBC
A
erythropoiesis
13
Q
what is the name given for formation of WBC
A
myelopoiesis
14
Q
what is the name given for formation of platelets
A
thrombopoiesis
15
Q
describe the general process of haemopoiesis
A
starts as hemocytoblast (multipotent hematopoietic stem cell) then divides into common myeloid progenitor (for everything apart from lymphocytes) or into common lymphoid progenitor (for lymohocytes)
16
Q
what is the GF for RBC and where is it made
A
erythropoietin (EPO); kidneys
17
Q
what is the GF for WBC
A
granulocyte macrophage colony stimulating factor (GM-CSF)
18
Q
What is the GF for platelets
A
thrombopoietin (TPO)
19
Q
what is the definition of anaemia
A
deficiency of Hb; normal range I 12.5-15.5g/dL
20
Q
what are the Hb values of anaemia for adults
A
o <13.0g/dL in males
o <12.0g/dL in females
21
Q
what is polycuthaemia and what are the causes
A
raised Hb; caused by smoking, lung disease, inefficient lungs meaning less O2 is exchanged so more Hb required etc
22
Q
what is the presentation of acute anaemia
A
blood loss leads to loss of RBC and plasma; low Hb but haematocrit remains constant
23
Q
what is the presentation of chronic anaemia
A
loss of RBC due to inflammatory disorders/ malignancy, low HB and reduced haematocrit
24
Q
Types of anaemia
A
iron deficiency, megaloblastic/ macrocytic, haemolytic
25
what is megaloblastic anaemia
vitamin B12/ folate deficiency; needed for DNA synthesis so lack means incorrect RBC production so reduced normal RBC so low Hb
26
Describe erythrocytes
anucleate, discoid, biconcave
| no mitochondria so anaerobic respiration
27
where is lactate broken down
liver
28
what is the life span of erythrocytes
120 days
29
what is special about erythrocytes membrane
encloses glycolysis enzymes and Hb
30
what is the name for young RBC
reticulocytes
31
describe the structure of haemoglobin
tetrameric protein - 4 globin chains
Haem group made in mitochondria
2 alpha chains, 2 beta chains
allows oxygen to reversibly combine with fe2+ in aqueous environment
32
describe foetal Hb
2 alpha and 2 gamma chains (not beta)
33
what is the lifespan of neutrophils
6-10h
34
what is the prevalence of neutrophils
most numerous WBC
| 1.8-7.5 x 10^9/L
35
what is neutrophilia
neutrophils > 10 x 10^9/ L - due to infection/ tissue necrossi
36
what is neutropenia
neutrophils < 1.5 x10^9
37
describe neutrophils
multi-lobed nucleus
cytoplasm full of granules as phagocytic
inflammatory response - release chemotaxis and cytokines
38
what do chemotaxis do
signal more WBC to come to site
39
what do cytokines do
inflammatory response
40
what is the lifespan of monocytes
20-40h
41
what is the purpose of monocytes
macrophages (phagocytose) and dendritic cells (present antigens to immune system)
42
what is the lifespan of basophils
days
43
what it he prevalence o basophils
rare in peripheral blood
44
what happens when basophils migrate to tissue
become mast cells; filled with histamine containing granules and express surface IgE
45
what is the role of basophils
important in immunity/ allergic response
46
what is the lifespan of eosinophils
days
47
what is the prevelance of eosinophils
rare in peripheral blood; 0.04-0.4 x10^9/ L
48
what is the role of eosinophils
immunity and allergic response, special role in protection against parasites
49
what do eosinophils look like
red - lots of granules in cytoplasm
50
what is the lifespan of lymphocytes
weeks-years
51
describe B-lymphocytes
20% of lymphocytes, mature in bone marrow, stored in secondary lymohoid organs, differentiate into plasma cells which produce immunoglobulins when stimulated by exposure to foreign antibodies
52
describe T-lymphocytes
80% of lymphocytes, mature in thymus, aid B cells and generate cellular immunity
53
what are 2 subgroups of T-lymphocytes
helper cells - CD4+; supress/ regulate immune system
| natural killer cells - CD8+; target damaged cells for death
54
describe the formation of platelets
myeloid cells differentiate into megakaryoblast which becomes megakaryocyte; membrane blebbing leads to platelets forming
55
describe megakaryoblast cells
polyploid cell - multiple copies of cjhromosomes due to endomitosis
56
what is endomitosis
DNA replication but not cell division
57
what is the lifespan of platelets
7-10 days
58
what is the prevalence of platelets
140-400x10^9/ L
59
describe platelet structure
enucleate, contain 3 types of granules - alpha, delta and peroxisomes
circulate in inactive form, spiculated once activated
60
where are platelets made
bone marrow
61
what is the role of platelets
primary haemostasis
62
describe primary haemostasis
platelets adhere to gap in membrane of vessel, change shape so activate, release contents = degranulate, aggregate to form platelet thrombosis
63
what is thrombocytopenia
reduced platelet number; low means increased bleeding, very low means spontaneous bleeding
64
what is thrombocytosis
high platelet number
| arterial and venous thrombosis means increased risk of MI/ stroke
65
what do platelet alpha granules contain
clotting factors
66
what do platelet delta granules contain
serotonin - absorbed into them from plasma following sicharge of clotting factors
67
what do platelet peroxisomes contain
catalase - enzyme used in elimination of oxygen free radicals
68
where is albumin produced
liver
69
what does albumin do
determines oncotic pressure of blood so keeps intravascular fluid in that space
70
what does albumin carry
FA, steroids, thyroid hormones
71
what does lack of albumin lead to
oedema, liver disease, nephrotic syndrome
72
types of soluble plasma proteins
albumin, immunoglobulin, carrier proteins
73
what is vitamin K needed for
correct synthesis of coagulation protein 2, 7, 9, 10- circulates in inactive form
74
what is prothrombin time
measures rate of blood clotting
75
what does thrombin do
converts soluble fibrinogen into insoluble fibrin polymer to generate stable vlot
76
what is haemostasis
maintaining balance of blood inside vessel remaining fluid
77
what activates platelets/ proteins of coagulation cascade
circulate in inactive state, activated by tissue factor present on all cells except endothelial cells
78
what is a brief overview of platelet plug formation
endothelium disrupted, exposing collagen fibres
platelets adhere to VWF which is bound to collagen
binding leads to exocytosis of secretory vesicles which leads to platelet amplification
platelets are activated and becomes spiculated
fibrinogen binds to platelets allowing more platelets to aggregate and platelet plug forms
79
how does a platelet plug stay where is it wanted
prostaglandins produced by undamaged endothelium inhibit aggregation, and NO from undamaged endothelium leads to vasodilation and inhibits aggregation
80
what is released from platelets when they bind to VWF
platelet dense granules release ADP leading to platelet amplification
coagulation factors
inflammatory mediators (alpha granules)
81
what does thrombin do
converts soluble fibrinogen to insoluble fibrin
| - accelerates production of factor 11a, 8a, 5a so amplifies cascade
82
describe the extrinsic pathway of clotting cascade
initialises coagulation cascade
TF released from damaged tissue
factor 7 converted to 7a
TF and 7a combine to convert 10 to 10a - continues like intrinsic pathway after this
83
describe the intrinsic pathway of clotting cascade
factor 12 to 12a, causes 11 to 11a, caises 9 to 9a, causes 10 to 10a using 8a
10a converts prothrombin to thrombin using 5
thrombin converts fibrinogen to fibrin
84
what is the purpose of the fibrinolytic system
regulation to prevent lethal clotting
85
describe the fibrinolytic system
plasminogen converted by plasminogen activators to plasmin, which hydrolyses fibrin strands so allows clot to dissolve
86
what is disseminated intravascular coagulation (DIC)
breakdown of haemostatic balance - simultaneous bleeding and microvascular thrombosis
87
what happens in DIC
activation of coagulation cascade inside blood vessels means thrombin is produced so fibrinogen is converted to fibrin so platelet plus form everywhere, leading to deficiency of CF and platelets and thus bleeding
88
what is haemophilia a
deficiency in CF 8
bleeding in muscles and joints
1 in 10,000 males -recessive x linked
89
what is haemophilia b
bleeding into muscles and jojnts
deficiency in CF 9
1 in 50,000 males
90
what is von Willebrand's disease
lack of VWF so platelet disfunction and muco-cutaneous bleeding
mild bleeding disorder
91
what is the inheritance of von Willebrand's disease
autosomal dominant - can have male to male, affects all generation
is a common disease
