Blood Flashcards
1
Q
What is the process called by which new blood cells are formed?
A
hematopoiesis
2
Q
What is the lifespan of a red blood cell?
A
120 days
3
Q
What is the lifespan of a circulating platelet?
A
7-10 days
4
Q
What percentage of blood is RBCs?
A
45%
5
Q
What percentage of blood is plasma?
A
55%
6
Q
What percentage of blood is white blood cells and platelets?
A
Less than 1%
7
Q
what else can a hemocytoblast be called?
A
hematopoietic stem cell
8
Q
What stem cells can a hemocytoblast form?
A
lymphoid stem cell and myeloid stem cell
9
Q
What do erythrocytes lack that many other cells have?
A
mitochondria and a nucleus
10
Q
List possible end products from a myeloid progenitor cell
A
Platelets, erythrocytes, macrophages, granulocytes
11
Q
What are the three granulocytes?
A
neutrophil, eosinophil, basophil
12
Q
What cell comes between the myeloid progenitor cell and the devlopment of a neutrophil?
A
myeloblast
13
Q
What type precursor cell to erythrocytes has no nucleus and enters the circulation before later maturing into an erythrocyte?
A
reticulocyte
14
Q
What large bone marrow cell that comes from myeloid progenitor cells is responsible for the production of platelets?
A
Megakaryocyte
15
Q
What do monocytes develop into, allowing them to enter peripheral tissues?
A
Macrophages
16
Q
What comprises the axial skeleton?
A
Skull, ossicles of the middle ear, hyoid bone, rib cage, sternum, vertebral column
17
Q
What can common lymphoid progenitor cells develop into?
A
T cells, B cells and natural killer cells
18
Q
Where does the production of red blood cells begin in utero?
A
yolk sac
19
Q
In the fetus where are the predominant sites of hematopoiesis?
A
Second trimester- liver
From 7 months- bone marrow
20
Q
Describe how the distribution of red marrow changes with age after birth.
A
In the first 4 years- almost all marrow cavities contain red marrow
In adults- red marrow is limited to the axial skeleton and long bones
21
Q
What is red marrow replaced with as we age
A
yellow marrow (fat)
22
Q
what does EPO stand for?
A
erythropoeitin
23
Q
Where is erythropoietin produced?
A
The kidney
24
Q
What is the most abundant leucocyte?
A
neutrophil
25
How many alpha and beta chains does adult haemoglobin contain?
2 alpha, 2 beta
26
What type of ring is present in the haem group?
porphyrin ring
27
Where do T cells mature?
The thymus
28
What is a T cell referred to when it has not yet encountered its specific antigen?
naive T cell
29
What do naive T cells with CD8 become?
cytotoxic T cells
30
What do naive T cells with CD4 become?
T helper cells
31
What do cytotoxic T cells release?
Cytotoxic granules
32
Gives examples of T helper cell subtypes
Th1 cells, Th2 cells, Th17 cells and regulatory T cells
33
What do T helper cells release?
cytokines
34
Where do B cells mature?
The bone marrow
35
What do plasma cells produce?
antibodies
36
What types of memory cells are there?
Memory T cells and memory B cells
37
Do all B cells require T cells to produce antibodies?
Most but not all. Ones that do not require the presence of T cells are called T-independent B cells
38
Where can you find the macrophages that break down old and damaged erythrocytes?
Spleen, Liver, Bone marrow
39
What is haemoglobin first broken down into by macrophages?
heme and globin
40
What is globin broken down into?
amino acids
41
What drives erythropoeisis?
hypoxia
42
Where is intrinsic factor produced?
the stomach
43
What type of cells produce intrinsic factor?
parietal cells
44
What does intrinsic factor bind to?
B12
45
In what part of the GI tract is the intrinsic factor bound to B12 absorbed?
The ileum
46
What does B12 bind to in the circulation?
transcobalamin I and II
47
Fe2+ leaves the enterocyte via what transporter?
ferroportin
48
On, leaving the enterocyte and entering the circulation, what is Fe2+ converted into?
Fe3+
49
Once in the circulation after absorption from the diet, what does Fe3+ bind to?
transferrin
50
Describe the roles of eosinophils
Role in protection against parasites, roles in inflammation and allergic response
51
Describe the role of neutrophils
Phagocytic, release chemotaxins and cytokines
52
What is chemotaxis?
Movement in response to chemical stimulation
53
How do platelets bind to collagen?
GP1a
54
How do platelets bind to VWF?
GP1b
55
What is the word for when a platelet is activated and releases its contents?
Degranulate
56
What percentage of blood plasma is water?
90%
57
What is serum?
Plasma without clotting factors
58
Where is albumin produced?
The liver
59
What forms the bridge between GPIIb/IIIa receptors on platelets, binding them together?
fibrinogen
60
What is primary haemostasis?
Formation of the primary platelet plug
61
What is secondary haemostasis?
Coagulation cascades
62
What are the 5 steps of haemostasis?
1. Vascular spasm
2. Platelet plug formation
3. Coagulation
4. Clot retraction and repair
5. Fibrinolysis
63
What is vascular spasm?
Endothelin- Damaged epithelial cells release endothelin-> endothelin causes contraction of smooth muscle -> vasoconstriction
Myogenic mechanism- direct injury to smooth muscle causes contraction
Nociceptors- stimulation causes contraction of smooth muscle
64
What helps to keep platelets inactive normally?
Endothelial cells secrete nitric oxide and PGI2
65
What substances that are released by activated platelets cause vasoconstriction?
Thromboxane A2 and serotonin
66
What is the function of prothrombin activator?
Converts prothrombin into thrombin
67
What does thrombin do?
Converts fibrinogen into fibrin
68
Describe the changes in solubility in plasma between fibrinogen and fibrin
Fibrinogen- soluble in blood plasma
| Fibrin- Insoluble in blood plasma
69
What does the cross-linking of fibrin strands create?
The fibrin mesh
70
Describe how the endothelial cells on either side of a section of damaged blood vessels get brought closer together?
Platelet contraction
71
What converts plasminogen into plasmin?
Tissue plasminogen activator
72
What does plasmin do?
Degrades fibrin mesh
73
What is oedema?
Excessive accumulation of serous fluid in the intercellular spaces of tissue
74
What type of antibody is capable of transplacental passage from mother to fetus?
IgG
75
Give two examples of agranulocytes
Monocytes and Lymphocytes
76
Put the granulocytes in order of most to least abundant
Neutophils, eosinophils, basophils
77
Which is more abundant- lymphocytes or monoctyes?
Lynphocytes
78
What is the most common white blood cell?
Neutrophils
79
Describe the nucleus of a neutrophil
Multi lobed
80
What three types of cytoplasmic granule do neutrophils contain?
primary, secondary and tertiary granules
81
Give an example of a primary granule found in a neutrophil
Lysosomes
82
Describe the action of secondary granules in the neutrophil
secrete substances that mobalise inflammatory mediators
83
In a parasitic infection which granulocyte would you expect to see an increase in number of ?
Eosinophils
84
Describe the nucleus of an eosinophil
bi-lobed
85
Describe the apppearance of the cytoplasmic granules of an eosinophil
Large red granules with crystalline inclusions
| Lozange shaped granules with crystalline cores
86
How do eosinophils effect mast cell secretion
Inhibit it
87
What effect do eosinophils have on histamine?
Neutralise histamine- restrict inflammatory responses
88
Describe the nucleus of basophils
bi-lobed
89
What do the granules in basophils contain
histamine
90
What do basophils release in response to allergens?
histamine
91
What are basophils the circulating from of?
The tissue mast cell
92
Can you tell different lymphocytes apart on H&E stained section?
Nope. They all look the same
93
What is the main role of natural killer cells?
maily kill virus infected cells
94
What is the tole of T suppressor cells?
Suppress T helper cells and therefore suppress the immune response
95
What is the role of T cytotoxic cells?
Kill previously marked target cells
96
Describe the nucleus of monocytes
Reniform
97
What can monocytes differentiate into?
```
tissue macrophages-everywhere
Kupffer cells-liver
Osteoclasts-bone
Antigen presenting cells-everywhere
Alveolar macrophages-lung
```
98
What blood types can someone who has type A blood donate to?
A and AB
99
Which blood type has no antigens?
O-
100
What type of antibodies will someone with type A blood have?
Anti-B antibodies
101
Will someone with AB blood have any anti A or anti B antibodies?
No
102
Hemolytic disease of the newborn occurs when the mother and baby have what blood types?
Mother- Rh-
Baby-Rh+
Antibodies produced by the mother can attack the baby's red blood cells
103
Who can someone who is Rh negative donate to?
Someone who is either Rh positive or negative
104
Who can someone who is Rh+ donate to?
Someone who is also Rh positive but not anyone who is Rh negative
105
What are the possible geneotypes for someone who has type A blood?
AA or AO
106
When a platelet is activated describe how it changes shape
Surface area increases
107
With regards to the GPIIb/IIIa receptors, what changes occur after the platelet is activated?
Number of GPIIb/IIa receptors increases
108
What causes the increase in affinity for fibrinogen after a platelet is activated?
An increase in the number of GPIIb/IIa receptors
109
What is firbinogen a precursor to?
Fibrin
110
What is atherogenesis?
the formation of fatty deposits in the arteries
111
Describe how a platelet can be activated
Thrombin- activates platelets( and cleaves fibrinogen into fibrin)
Thromboxane A2- activates platelets
Collagen- GP6 receptor binds to collagen, activating platelets
ADP
112
What receptors do platelets have for collagen?
Glycoprotein VI
| Glycoprotein Ia/IIa
113
What does COX stand for?
Cyclooxygenase
114
What is the role of COX-1 in platelets?
Converts arachidonic acid into prostaglandin H2 and then thromboxane A2
115
Which cyclogenoxygenases are involved in prostacyclin production in endothelial cells?
COX-1 and COX-2
116
What is are the precursors to prostayclins produced in the endothelial cells?
Arachidonic acid and prostaglandin H2 (Prostaglandin H2 comes after arachidonic acid)
117
Describe the role of COX-1
Thromboxane A2 mediated platelet aggregation
118
What does COX-2 mediate?
Prostacylin production
119
What does prostacyclin inhibit?
Platelet aggregation
120
What type of receptors are P2Y1 and P2Y12?
G-protein coupled receptors
121
What binds to P2Y1 and P2Y12?
ADP
122
Binding of ADP to P2Y1 receptors has what effect?
Initiates platelet activation
123
Binding of ADP to P2Y12 receptors has what effect?
Amplification of platelet activation via reducing inhibition of activation
124
What type of granules release ADP when a platelet is activated?
Dense granules
125
What receptor does thrombin bind to?
PAR-1
126
Describe the position of aminophospholipids in a resting platelet
Aminophospholipids are on the inner layer of plasma membrane
127
What ion is released from inracellular stores when a platelet is activated?
CA++
128
What does Ca++ activate in the platelet?
scramblase
129
What does Ca++ inhibit in the platelet?
translocase
130
How does the position of the aminophospholipids in the platelet change due an increase in Ca++?
Causes aminophospholipids to be on the outher layer of the membrane
131
What enzyme forms on the surface of the platelet as a result of increased Ca++?
prothrombinase
132
What is the other name for clotting factor X?
prothrombinase
133
What is clotting factor II?
Thrombin
134
What type of cell releases tissue plasminogen activator?
endothelial
135
What is fibrin broken down by plasmin into?
fibrin degradation products
136
What does P-selectin allow platelets to bind to?
white blood cells
