blood Flashcards
1
Q
what is the blood composed of?
A
cells and plasma
2
Q
what are the cells in the blood?
A
- red blood cells 99%
- white blood cells
- platelets
3
Q
what is another word for red blood cells?
A
erythrocytes
4
Q
what is another word for white blood cells?
A
leucoctyes
5
Q
what is another word for platelets?
A
thrombocytes
6
Q
what makes up the plasma?
A
- extracellular fluid
- water
- electrolytes
- organic molecules
- glucose
- fatty acids
- amino acids
- plasma protein
7
Q
what are proteins in the plasma?
A
- albumins
- globulins
- fibrinogen
- regulatory proteins
8
Q
what % of plasma proteins are albumins?
A
60%
9
Q
what % of plasma proteins are globulins?
A
35%
10
Q
what % of plasma proteins are fibrinogen?
A
4%
11
Q
what % of plasma proteins are regulatory proteins?
A
1%
12
Q
what is the function of albumin proteins in the plasma?
A
- oncotic pressure and transport of lipids
13
Q
what is the function of globulin proteins in the plasma?
A
- transport ions, hormones, lipids
- immune function
14
Q
what is the function of fibrinogen proteins in the plasma?
A
- blood clotting
15
Q
what are the regulatory proteins in the plasma?
A
- enzymes
- hormones
16
Q
what does blood volume depend on?
A
individual’s size (males have more)
17
Q
what % of blood is plasma?
A
55%
18
Q
what % of blood do cells make up?
A
45%
19
Q
describe red blood cells
A
- Biconcave disc shape
- 6-8 μm diameter
- Shape gives large surface area relative to volume.
- Permits rapid gas (O2, CO2) transfer across cell
membrane - Allows RBC to ‘bend’ in narrow capillaries.
- Biconcave shape enable RBC to expand to accommodate
fluid in hypotonic solutions. - ‘Older’ RBC are more ‘fragile’ in hypotonic solutions.
20
Q
what is commonly seen in blood film staining?
A
missing centres due to halo effect
21
Q
where are red blood cells formed?
A
red bone marrow
22
Q
what is the average lifespan of a red blood cell?
A
120 days
23
Q
what happens to old red blood cells?
A
they are removed from the circulation and broken down by the mononuclear phagocyte system (spleen)
24
Q
what mainly makes up the mononuclear phagocyte system?
A
spleen
25
what is haemoglobin?
a protein- iron-containing oxygen-transport metalloprotein in red blood cells
26
what is the mononuclear phagocyte system?
also known previously as the reticuloendothelial system, part of the immune system . This helps form new blood cells, removes old red blood cells, forms bile pigments and plasma proteins and helps to store iron.
27
where is bilirubin conjugated?
the liver
28
what is bilirubin excreted as?
bile pigement
29
what is transferrin?
glycoprotein that mediates the transportation of iron
30
what % of blood cells formed are ineffective?
10%
31
what happens to the blood cells formed that are ineffective?
go through haemolysis
32
what is hamolysis?
destruction
33
what is the process that produces red blood cells?
erythropoesis
34
what regulates erthropoesis?
erythropoietin- glycoprotein cytokine
35
what happens to the cells during erythropoesis?
there's a reduction in cell size and regression of nucleus requiring folic acid and vitamin B12 and increases in haemoglobin requiring iron
36
describe the stages following a decrease in red blood cell numbers
- less oxygen delivery to cells
- less oxygen delivered to kidney
- erythropoietin released
- red bone marrow
- increase in red blood cell production
36
describe the stages following a decrease in red blood cell numbers
- less oxygen delivery to cells
- less oxygen delivered to kidney
- erythropoietin released
- red bone marrow
- increase in red blood cell production
37
what are the functions of haemoglobin?
transport oxygen
transport of carbon dioxide
- carbonic anhydrase
- bicarbonate production
- carbamino compounds
38
describe the structure of haemoglobin
Globular protein
- molecular weight= 64,000 daltons
- 2 α & 2 β protein chains (diag)
- 4 haeme groups:
– Porphyrin ring (4C, 1N)
– Iron atom in middle, C and H around
- Fe reversibly binds O2
- 200-300 Hb molecules / RBC
- (Foetus has Hb-F)
39
describe the trend in the Hb-O2 dissociation curve
Oxygen saturation increases rapidly with small increases of partial pressure of O2 to a point of saturation of the haemoglobin at 98%
40
what are the two classifications of white blood cells?
granulocytes and agranulocytes
41
what is the difference between granulocytes and agranulocytes?
granulocytes have granules in their cytoplasm
42
what are examples of granulocytes?
- neutrophil 50-70%
- basophil 1%
- eosinophil 2-4%
43
what are examples of agranulocytes?
- monocyte 2-8%
- lymphocyte 25-30%
44
what is the function of neutrophil white blood cells?
- acute inflammation
- phagocytic
- non-specific defence
45
what is the function of basophil white blood cells?
- circulating mast cells
- produce heparin
- histamine
46
what is the function of lymphocyte white blood cells?
- cell-mediated immunity T
- humoral immunity (antibody producing) B
47
what is the structure of a neutrophil?
- Multi-lobed nucleus with condensed chromatin
- 12-14 micrometres in diameter
- lifespan of a few days
- basophilic (dark staining)
- few organelles
48
what is the structure of a eosinophil?
- 12-17 micrometres in diameter
- larger than the neutrophil
- bi-lobed nucleus, but can further segment with age
- eosinophilic cytoplasm
- Defend against parasites especially works and maintain inflammatory responses eg allergic rhinitis
49
what is the structure of a basophil?
- least common leucocyte
- intermediate in size as 14-16 micrometres between neutrophils and eosinophils
- Bilobed nucleus, very basophilic granules
- Formed in bone marrow
50
what is the structure of a monocyte?
- Monocytes are the largest of the white cells (up to 20 µm in diameter) and constitute from 2% to 10% of leucocytes in peripheral blood.
- They circulate for 3 to 4 days on average before migrating into tissues.
- These cells are motile, highly phagocytic and may mature in tissues into tissue resident macrophages of varying kinds with extended lifespans.
- Monocytes are characterised by a large, eccentrically placed nucleus which stains less intensely with more open chromatin than other leucocytes.
- Nuclear shape is variable but often with a deep indentation in the nucleus near to the centre of the cell, giving a horseshoe shape. Two or more nucleoli may be visible.
- Cytoplasm is abundant and stains pale greyish-blue. There are numerous small, purple-stained lysosomal granules and cytoplasmic vacuoles which confer a ‘frosted-glass’ appearance.
- Monocytes circulate in the blood. They respond to chemotaxic signals from damaged tissue, microorganisms and inflammation by migration into the tissues and differentiation into macrophages
51
describe the structure of a lymphocyte
Most circulating lymphocytes measure 6 to 9 µm (i.e. about the same size as erythrocytes) and are called small lymphocytes. About 3% are large lymphocytes , measuring 9 to 20 µm.
52
what are platelets derived from?
megakaryocytes- large bone marrow cell
53
describe platelets
Involved in haemostasis (stopping blood- for clotting)
Release vasoconstrictors (Thromboxane A2 (TxA2))
Form platelet plug
Source of phospholipid (‘platelet factor’) for coagulation.
Normal platelet count = 150-400 x 109 / litre
54
what do erythrocytes carry on their membranes?
antigens
55
what are antigens?
substances which can cause an immune response
56
which antigens are important in relation to blood transfusion?
- AB antigens
- Rhesus antigens
57
what determines the blood group/type of an individual?
the presence/absence of AB/Rh antigens on erythrocyte membranes
58
what are the natural antibodies to group A phenotype?
anti-B
59
what are the natural antibodies to group B phenotype?
anti-A
60
what are the natural antibodies to group O phenotype?
anti-A and anti-B
61
what % of people are rhesus positive?
83%
62
what happens if a Rh-negative person receives Rh-positive blood?
they develop anti-Rh antibodies- don't affect the person but can affect their children
63
describe Rh-incompatibility
- If Rh-negative person receives Rh-positive blood, they will develop anti-Rh antibodies.
- These antibodies will not affect the recipient, because they have no Rh-antigen.
- However, if an Rh- female conceives Rh+ foetus, some of the fetal RBCs can enter maternal circulation at birth.
- Anti-Rh antibodies are formed.
- These can attack and haemolyse the RBCs of a subsequent Rh+ foetus.
– Haemolytic disease of the newborn
64
what blood transfusion should patients ideally be given?
blood compatible with their group
65
why, in emergencies, can O- blood be given to anyone?
Gp O = Universal donor (This notion is now being challenged, as the situation is very complex.)
Similarly, a Group AB person can receive blood of any other group as Gp AB = Universal recipient.
66
where is red bone marrow found?
in spongy bone- ends of bones
