1. Haempoeisis Flashcards
(117 cards)
1
Q
What is haematology?
A
The study of blood. The diagnosis and monitoring of diseases of the blood and blood organs
2
Q
What is haemopoiesis?
A
The process by which cellular elements of the blood are formed
3
Q
What is the most numerous type of blood cell?
A
Red blood cells
4
Q
What is the normal range of a red blood cell?
A
4.0-5.5 x10^12/L
5
Q
What size are red blood cells?
A
6.7-7.7 um diameter
6
Q
What shape are the red blood cells?
A
Bi concave
7
Q
What is the normal life span of a red blood cell?
A
110-120 days
8
Q
What is the least numerous type of cell?
A
White blood cells
9
Q
What is the normal range of a white blood cell?
A
3.5-10 x10^9/L
10
Q
What are the 5 types of white blood cells?
A
lymphocytes, neutrophils, eosionphils, basophils and monocytes
11
Q
What is the normal range for a lymphocyte?
A
1.2-3.5 x10^9
12
Q
What is the purpose of lymphocytes?
A
Fight viral infections and produce antibodies
13
Q
What is the life span of a lymphocyte?
A
4/5 years
14
Q
What is a granulocyte?
A
White blood cells that contain granules in their cytoplasm
15
Q
What are the three types of granulocyte?
A
neurophils, basophils and eosinophils
16
Q
What is the normal range of neutrophils?
A
1.5-7.5 x10^9/L
17
Q
What is the purpose of neutrophils
A
To fight against bacterial infections. Pus cells. Phagocytic.
18
Q
What do neutrophils look like?
A
3 lobes with fine, faint granules.
19
Q
What is the half life of a neutrophil?
A
7 hours
20
Q
What is the normal range of an eosinophil?
A
0.03-0.6 x10^9/L
21
Q
What is the role of an eosinophil?
A
Release histamine in allergic reactions. Regulate hypersensitivity reactions. Effector cell for antibody-dependent damage to parasite.
22
Q
How many lobes do eosinophils have?
A
2
23
Q
What is the normal range for basophils?
A
0.01-0.15x10^9/L
24
Q
What do basophils look like?
A
Two lobes with dark asurophilic granules.
25
What do the granules in basophils contain?
Enzymes
26
What is the purpose of basophils?
Moderate inflammatory response. Releases heparin and proteases
27
What is the normal range for a monocyte?
0.2-0.8x10^9/L
28
What is the purpose of a monocyte?
To fight bacterial infections
29
Which two white blood cells fight bacterial infection? Which fight viral?
Bacterial: monocyte and neutrophil. Viral: lymphocyte
30
Which white blood cell releases histamines?
Eosinophils
31
Which white blood cells cause moderate swelling?
Basophils
32
Which white blood cells are responsible for pus?
Neutrophils
33
What is are monocytes precursors for?
Macrophages
34
What is the purpose of a monocyte?
To phagocytose bacteria and cells coated with antibodies
35
What is the lifespan of a monoctye?
70 hours
36
What is the normal range of a platelet?
150-400 x10^9/L
37
What is the structure of a platelet?
Discoid shape, 3-5ums
38
What is the life span of a platelet
7-10 days
39
What is the purpose of platelets?
Blood clotting (plug at site of injury - primary haemostasis)
40
What is the site of haemopoiesis in a 2 week old embryo?
Yolk sac
41
What is the site of haemopoiesis in a 12-16 year old embryo?
Liver and spleen
42
What is the site of haemopoiesis at birth?
Bone marrow of all bones
43
What is the site of haemopoisis in an adult?
Proximal ends of long bones, flat bones (sternum), pelvis and vertibrae
44
What is the difference between yellow marrow and red marrow?
Yellow marrow is inactive marrow, red is activated
45
What are the three stages of haemopoeisis?
Proliferation, Differentiation, Apoptosis
46
What regulates haemopoeis?
Growth factors
47
What are the names of the two groups of growth factors that regulate haemopoiesis?
Colony stimulated factors, interleukins
48
What are haemopoeitic growth factors?
Glycoprotiens
49
Where are haemopoetic growth factors produced?
By stroma cells in T lymphocytes, liver and kidneys
50
What is a haemopoeitic stem cell?
A cell from which all blood cells form. It can develop into a seperate lineage
51
From what is a haemopoetic stem cell originate from?
Mesoderm of embryonic development
52
Where are haemopeitic stem cells located?
Bone marrow
53
What is erythropoiesis?
Red blood cell production
54
What regulates erythropoiesis?
Erythropoietin
55
What is the earliest precursor for erythropoiesis?
Proerythrocyte (BM-pronormoblast)
56
What is another name for a proeyrthrocye?
BM-pronormoblast
57
What are the names of the normoblasts when they divide (the different stages)?
early, intermediate, late
58
What is the name of a red blood cell stem cell?
Haemocytoblast
59
What is a reticulocyte?
An immature red blood cell who's nucleus contains ribosomal RNA
60
What is nuclear extrusion?
When a nucleus is forced or moved out of a cell
61
Describe the steps in erythropoiesis?
Haemocytoblast, pronormoblast, erythroblast, normoblast, reticulocyte, erythrocyte
Erythropoeisis begins in the red bone marrow of long bones, flat bones (sternum, vertibrae and pelvic bone.
1) Haemocytoblasts (that have arisen from the mesemchyme) are able to give rise to red blood cells and all other blood cells. They are unipotent haemopoietic stem cells.
2) The haemocytoblasts commits to becoming blood cells and differentiates into proerythrocytes (myeloid poginator/pluripotent stem cell). The proerythrocyte is able to self-renew so that blood cells can be constantly formed.
3) Phase 1: Pronormoblasts receives signals from erythopeitin to become a red blood cell. The cell begins ribosome synthesis and becomes an early erythoblast.
4) Phase 2: Haemoglobin accumulated in the erythoblast, changing the erthyrocyte from early-stage to late-stage erythoblast. The late erythoblast becomes a normoblast.
5) Phase 3: The normoblast ejects the nucleus (nuclear extrusion) and other organelles (such as mitochondria). The normoblast becomes a reiticuloctye. Although the cell is now enucleated, it is still capable of producing haemoglobin.
6) The reticulocyte leaves the bone marrow and enters circulation to become an erythrocyte. 1% of newly circulating RBCs are reticulocytes.
62
What shape are erythocytes?
Bi concave
63
What advantage do the RBCs have by having a biconcave shape?
They are flexible and therefore able to pass through the membrane of capillaries. Biconcave means they have a greater surface area to volume ratio so maximum oxygen/CO2 transportation.
64
How long do red blood cells circulate?
110-120 days
65
What causes the death of red blood cells?
Loss of red-cell enzyme causes them to lose their shape and flexibility.
66
Where are RBCs destroyed?
Bone marrow, spleen and liver
67
What of the cellular components can be recycled?
The protein, lipids and iron
68
What happens to the components that cannot be recycled?
They are excreted through the liver to faeces and urine
69
Are RBCs able to traverse the endothelial membrane? (what lines the blood vessels)
No
70
What is granulopoiesis?
The formation of granulocytes neutrophils, eosinophils and basophils
71
Which are the most numerous granulocytes in circulation?
Neurophils
72
How long are neutrophils in circulation?
10 hours
73
What are granulocytes produced from?
Myeloid precursor cells
74
What regulates granulopoeisis?
haemopoietic growth factors
75
What are the haemopoietic growth factors that regulate grabulopoiesis?
IL3, GM-CSF, IL5
76
What does growth factor IL3 regulate?
Nuerophils, monocytes and basophils
77
What does growth factor IL5 regulate?
eosinophils
78
What does GM CSF
granulocyte macrophage colony-stimulating factor
79
What are the stages of granulopoiesis?
haemopoietic stem cell (haemocytoblast), myeblast, promyelocyte, esosino/neutro/baso myelocytes, metamyelocyte, band cell (stab cell), mature granulocyte
80
What is monocytopoiesis?
The production of monocytes (macrophages)
81
What are the stages of monocytopoiesis?
1) Haemoctoblast to common myeloid proginator
2) myeloid proginator to monoblast
3) monoblast to promonocyte
4) promonocyte to marrow monocyte
5) marrow monocyte to blood monocyte
6) blood monocyte to tissue macrophage
82
Why aren't macrophages not 'important; in haematology?
They cant be seen in peripheral blood (only in tissues) so not imporant
83
What is the purpose of blood monocytes?
They phagocytose and destroy bacteria
84
How long to blood monocytes last in circulation?
20-40 hours
85
Descibe the appeance of blood monocytes
Greyish cytoplasm, variable morphology (shapes), mono nuclear
86
What is lymphopoiesis?
Lyphopoiesis is the generation of lyphocytes (5 types of white blood cells)
87
What growth factors regulate lymphopoiesis?
IL 1, 2, 4, 6, 7
88
What is the process of lymphopoiesis?
1) haemoctyoblast to myeloid progenitor
2) myeloid proginator to lymphobast
3) prolymphoblast to large lymphoctye
4) large lymphoctye to small lymphocyte
5) small lymphocytes undergo either B or T lymphopoiesis
89
What are the two types of lymphoctyes?
B and T
90
Describe B cell lymphocytic development
Haemocytoblastic cells to myeloid pregenitor to lymphocytic (pluripotent) stem cells
1) lymphoctye stem cells found in the bone marrow
2) B lymphoctye proginators are generated from the lymphoctye stem cells
3) B cells generate and mature in the bone marrow
4) B cells migrate via the blood to peripheral lymphoid tissues (spleen, lymph nodes)
91
Describe T cell lymphocytic development
Haemocytoblastic cells to myeloid pregenitor to lymphocytic (pluripotent) stem cells
1) Lymphocytic stem cells are found in bone marrow
2) T cell Lymphocyte proginators develop from the lymphocytic stem cells
3) T cells are generated in the bone marrow but migrate to the blood to the thymus
4) They mature in the thymus
5) T cells then migrate to peripheral lymph organs
92
What type of immmunity does the B cells produce?
Hummoral immunity (blood immunity)
93
How to B cells carry our their jobs?
As B cells are in lymph nodes, they recieve a constant supply of antigens from lymph.
1) Receptors on the surface of B cells recognise foreign antigens
2) When foreign antigens are detected in the blood, the B cells proliferate
3) B cells secrete antibodies against foreign antigen
4) Can produce rapid response to further contact with invading antigen
94
How to T cells carry out their jobs?
1) T cell antigen is antigen specific therefore antigens must be presented to T cells by macrophages (after being processed)
2) T cell is activated and can proliferate into: T helper, T memory, T regulatory, T cytotoxic and Natural Killer cells
95
What kind of immunity do T cells provide?
Cellular immunity
96
What is the purpose of thrombopoiesis?
Thrombocyte generation (platelet development that can be used in blood blood clotting)
97
Why is platelet production important?
For blood clotting. They form plug at site of injury.
98
What regulates thrombopoiesis?
Thrombopoeitin
99
What do platelets interact with to form a barrier against blood loss?
Von Willebran factor
100
Platelet aggregation causes what?
Barrier to blood loss. Thrombus.
101
What surface do platelets provide to support wound healing?
Negatively charged lipid surface which supports coagulation
102
What do platelets do? 6
1) provides barrier to blood loss using Von Willebran factor
2) aggregate to form thrombus
3) create negatively charged lipid surface to support coagulation
4) Localises thrombus formation
5) Promotes vasoconstriction
6) Promotes vessel repair
103
What is the process of thrombopoiesis?
haemocytoblast cell has become undergone myeloid proginator
myeloid proginator to megakayroblast
megakaryoblast to promegakaryocyte
promegakaryocyte to megakaryocyte
megakaryocyte to platelet (platelets discharge from megakaryoctye)
104
What kind of DNA replication does thrombopoeisi involve?
Endomitotic replication
105
What is endomitotic replication?
Replication of DNA without nuclear division.
106
What happens to a cell at the end of a cycle of endomitotic replication?
The cell becomes larger with each replication. The cell is a large uni-nucleated cell with 64n DNA and has large cytoplast
107
Where are platelets formed?
Cytoplasm of mature megakayrocyte.
108
Where do platelets go after they have been discharged from the megakarycyte?
The bone marrow
109
What happens to the nucleus of the megakaryoctyes after they have released the platelets?
Engulfed by macrophages and phagocytosed
110
How long does thrombopoeisis take?
2-3 days
111
How many platelets can be made from each macrophage?
200-700 platelets
112
What shape are platelets?
Discoid
113
Are platlets dormant or active in blood?
Dormant
114
How do platlets circulate in regards to blood vessels?
At the edge of blood vessels due to shape
115
What is primary haemostasis?
It is platelet activation, adhesion and aggregation. It leads to plug formation and triggers secondary haemostasis.
116
When is secondary haemostasis triggered?
When primary haemostasis was not sufficient to stop bleed. Reinforments is needed via biochemical reactions
117
What happens during secondary haemostasis?
soluble fibrinogen is transformed to insoluble fibrin. Fibrin intertwines with cells of the forming thrombus to form a 'scaffold'.
