Blood Flashcards
(128 cards)
1
Q
what make ups 90% of the cells in the blood?
A
Erythrocytes
2
Q
What is the structure of an erythrocyte?
A
Typical lipid bilayer membrane of globular proteins
Biconcave disc shape
Elasticity/deformability
3
Q
What are erythrocytes shaped like biconcave disks and why have they got elasticity?
A
- increases surface area (20-30%)
- Allows passage through capillaries with diameters as small as 3-4μ (erythrocytes are 7μ)
4
Q
What would cause erythrocytes to swell and lose their normal biconcave disc morphology?
A
Damage to the membrane leading to a failure of Na+ ion movement across erythrocyte cell membranes
5
Q
What causes the short lifespan of erythrocytes?
A
Moving through capillaries they are too large for, this stresses them out
6
Q
When the membrane of the erythrocyte gets damaged it causes residue on the surface, what does this then lead to?
A
Removal and recycling of lots of red blood cell components
7
Q
What properties do dog erythrocytes have?
A
- Uniform in size
- Central pallor (pronounced concave shape which you can see under the microscope)
8
Q
What properties do cat erythrocytes have?
A
- Anisocytosis (variation in cell size)
- Smaller
- Scarce central pallor (less concave)
9
Q
What properties do horse erythrocytes have?
A
- Rouleaux formation (Clustering of RBCs in standing blood – most other species would be a sign of inflammation)
10
Q
What properties do ruminant erythrocytes have?
A
- Crenation (spiky appearance – can show rogh handling of blood OR disease in dogs and cats)
- Variation in size
11
Q
What properties do camelid erythrocytes have?
A
Elipsoid shape - unusual in mammals, common in birds and retiles
12
Q
What properties do chicken and reptile erythrocytes have?
A
- Nucleated – not as specialised for transporting O2 like mammals are
- Larger
- Early stages are rounded and may be binucleate
- Occasional cells lose their nucleus and are termed erythroplastids
- Elipsoid shape
13
Q
Why are erythrocytes metabolically active?
A
To maintain electrolyte gradients across the plasma membrane and of haemoglobin molecules (95% of erythrocyte proteins)
14
Q
Why don’t erythrocytes have organelles?
If they don’t have mitochondria how do they get their energy?
A
To avoid consumption of any oxygen they are carrying
It is derived by the anaerobic metabolism of glucose
15
Q
Erythrocytes don’t have a nucleus (in mammals) so how does division occur?
What are the benefits to having no nucleus?
A
Division happens at stem cells
Increased space for haemoglobin and allows biconcave shape
16
Q
What is the main role of erythrocytes?
A
Transport of O2 from the lungs to the cells
17
Q
How much oxygen is stored in haemoglobin and how much is dissolved into the blood?
A
Haemoglobin: 98.5 %
Dissolved in blood: 1.5%
18
Q
What is the other role erythrocytes have?
A
Transport of CO2 from the cells to the lungs
19
Q
How much CO2 becomes bicarbonate, binds to haemoglobin or is dissolved in the blood?
A
Bicarbonate: 70-85%
Haemoglobin: 10%
Dissolved in blood: 5-15%
20
Q
CO2 diffuses into the capillaries and then into erythrocytes, it then becomes bicarbonate. What is the equation for this?
A
Carbonic anhydrase (CA)causes carbon dioxide and water to form carbonic acid (H2CO3), which dissociates into two ions: bicarbonate (HCO3–) and hydrogen (H+).
21
Q
In adult erythrocytes how many of units of haemoglobin are there and how many oxygen and bind to each?
A
4 haemoglobin units - 1 oxygen binds to the iron atom of the ham group
22
Q
In adult erythrocytes haemoglobin, what are the most common pairs of globin polypeptides?
What is highly unusual?
What is found in foetal?
What is found in embryonic/yolk sac?
A
Alpha and beta
Delta
Gamma
Epsilon
23
Q
What happens to blood depending on the amount of oxygen bound to it?
A
24
Q
What is the name given to haemoglobin in areas of high oxygen concentration (eg. in lungs)?
Why has it got this name?
A
oxyhaemoglobin
because globin releases CO2 and iron binds to O2
25
What is the name given to haemoglobin in areas of low oxygen concentration?
Why has it got this name?
Carbaminohaemoglobin
O2 is released and CO2 bound
26
What is hypoxic tissue?
What does it do?
When the tissue is lacking in O2
Additional carbohydrate (2,3-diphosphoglyceride) is released, it facilitates release of O2 from erythrocytes
27
What can haemoglobin also bind to that causes the dilation of blood vessels and what does this permit?
Binds to nitric oxide, a neurotransmitter
Maximal tissue perfusion for supply of oxygen/removal of waste products
28
What has a greater affinity for haem than oxygen?
Why is this problematic?
Carbon monoxide
Carbonmonoxyhemoglobin gives off the cherry red colour of the mucous membrane when really its carbon monoxide poisoning
29
Why is haematopoiesis a continuous replenishment process?
Cells cannot divide once in the blood so must be replenished in the bone marrow
30
What blood cellular components are formed during haematopoiesis?
red blood cells (erthrocytes)
white blood cells (leukocytes)
platelets (thrombocytes)
31
What are the following?
erthrocytes
leukocytes
thrombocytes
erthrocytes = red blood cells
leukocytes = white blood cells
thrombocytes = platelets
32
What is erythropoiesis?
The production of erythrocytes/red blood cells
33
Where does erythropoeisis occur in adult and later foetal stages?
Where does it occur in special circumstances?
Where does it occur in embryos?
Red bone marrow (contains blood stem cells) found at ends of long bones and in flat bones (e.g. ribs, pelvis + skull)
spleen
Yolk sac, liver (spleen)
34
What is highlighted in green?
Nucleated immature RBCs
35
What are sinusoidal capillaries?
Capillaries with larger intercellular gaps within their ednotheliums and incomplete basement membranes to allow passage of cells
36
What happens to marrow that is inactive?
Can it still produce RBCs?
Replaced by fat (yellow marrow)
Can regain activity by extension from active tissue and from circulating stem cells (if requiring RBC)
37
Identify the following cells:
38
What are retculocytes?
blood cell that has nucleus remnants (not fully matured) and can be used in an emergency were red blood cells are required
39
What organ is important for haematopoetics in fish?
The kidney, so if there is kidney problems there will potentially be RBC issues going on as well
40
What does pluripotent mean, what cell is pluripotent that's involved in erythropoesis?
Could given rise to multiple different cells
Stem cells
41
What happens to RBCs as they mature?
Nucleus becomes progressively smaller
Cell size becomes progressively smaller
Haemoglobin levels gradually increase
42
During erythropoiesis where would be the following cells be found, in the bone marrow or in the blood sample (in order of development)?
Erythrocyte
Erythroblasts/normoblast
Reticulocyte
Stem cell
BM - Stem cell
BM - Erythroblasts/normoblast
BM + BS - Reticulocyte
BS - Erythrocyte
43
What happens to the nuclear material in immature RBCs as they mature?
Nuclear material will be transported out of cell and engulfed by macrophages
44
What does the formation of erythrocytes require?
Adequate amounts of:
- protein
- iron
- copper
- folic acid
- vitamins (B2, B6, B12)
45
Why are folic acids and vitamins essential for the formation of erythrocytes?
Essential for DNA synthesis to allow mitosis and therefore erythropoiesis
46
Why is iron essential for the formation of erythrocytes?
Mainly involved with haemoglobin
47
In the body, what is iron split between?
~ 70% as haemoglobin;
~ 30% bound to ferritin in macrophages and hepatocytes, insoluble
~ Some (<0.1%) bound to transferrin
48
Why is iron tightly bound to protein/transferrin in the plasma when moving to the liver, spleen or bone marrow?
Free iron is toxic to cells (damages DNA and protein) as it acts as a catalyst in the formation of free radicals from reactive oxygen species so must be bound at all times
49
Why is iron bound to ferritin found in the liver, spleen and bone marrow?
Liver and spleen: longer storage
Bone marrow: to produce RBCs
50
What are the causes of an iron deficiency?
1. Physiological anaemia in newborns
2. Blood loss
- Internal or external parasites
3. Haemorrhage
51
What is a good example of physiological anaemia in newborns and how it is treated?
Example: piglets
Markedly reduced RBC numbers in first 2-3 days of life
- Iron store used up within 1-2 days
- Sow milk contains very little iron
- Rapid growth due to selective breeding
52
What is Erythropoetin (EPO)?
Hormone that controls rate of erythrocyte production
(“Blood boosting drug”, doping horse racing to produce more red blood cells)
53
What stages of erythrocyte production is Erythropoetin (EPO)involved in?
All but especially during:
Erythroid cells precursors (CFU-Es) (stage prior to erythroblasts)
54
Where can EPO be found during early embryonic/foetal/early neonatal life?
Where can EPO be found during adult life?
Why is it important to know where EPO is produced?
expressed in yolk sac, liver and kidney (also spleen and bone marrow)
produced in the kidney (and renal interstitium area between renal cells)
Damage to these areas can lead to a negative impact on RBC production
55
Where can EPO be found during adult life?
produced in the kidney (and renal interstitium area between renal cells)
56
What regulates the secretion of EPO in the body?
The tissues need for oxygen
57
Fill in the blanks:
Low 1. oxygen
- Circulatory failure or 2. (normal O2, 3. delivery)
- Hypoxia (low O2)
Stimulates production of 4.
EPO transported by 5. to 6.
EPO binds to receptors on CFU-E (7.Erythroid cells precursors )
EPO also accelerates release of 8. blood
Low 1.tissue oxygen
- Circulatory failure or 2.anaemia (normal O2 but 3.low delivery)
- Hypoxia (low O2)
Stimulates production of 4.EPO
EPO transported by 5.blood to 6.bone marrow
EPO binds to receptors on CFU-E (7.)
EPO also accelerates release of 8.reticulocytes blood
58
What is the average erythrocyte life spans:
Cat
Dog, human
Horse
Cattle
Cat = 70 days
Dog, human = 120 days
Horse = 145 days
Cattle = 160 days
59
As RBCs age their surface becomes damaged, what are the 3 impacts of this?
- lose sialic acid residues from their surface
~ exposing galactose moieties that induce their phagocytosis
- become more fragile.
- may become swollen due to failure of normal membrane function
60
What is the normal lifespan of compatible transfused erythrocytes in dogs?
Why is it the length it is?
Approximately 21 days. – temporary, gives the animal more time to restore own cabibility of RBC production
Stress of collection and insertion and transport all contribute to short lifespan
61
What happens to damaged RBCs?
Phagocytized by macrophages breaking apart the harm and global into iron, bilirubin and amino acids and then these components are recycled
62
What happens to iron when haemoglobin is recycled?
What happens to bilirubin when haemoglobin is recycled?
Iron
- Goes to bone marrow for erythrocyte production
- Stored as ferritin
Bilirubin
- goes to the liver where it is excreted in bile
Amino acids
- goes into blood
63
What is happening in this diagram?
1. Transferrin synthesised in liver, binds to an iron to transfer it
2. Transferrin-iron complex binds to cell-surface receptors, the complex is then internalised (flips in the membrane so iron inside cell)
3. Lower pH inside cell, causes conformational change in transferrin and the iron is released
4. Receptor flips back, pH change to higher, causes conformational change to receptor and transferrin
5. Transferrin released ready to collect another iron
constant cycling system!
64
What are the two ways in which iron can be stored?
Ferritin
- primary intracellular storage protein, keeps iron soluble and non-toxic
- controls iron release, buffer against iron deficiency or overload
Haemosiderin
- Intracellular complex of ferritin (denatured ferritin and other material)
- Iron within deposits is poorly available to supply iron when needed (hard to resolualise)
- Large deposits cause organ damage as changes cell function
65
What is mycoplasma haemofolis?
What is neonatal erythrolysis?
Common in kittens
Bacteria attached to red blood cells causes removal of erythrocytes leading to anaemia
Common in kittens and foals (cause of really early disease)
Blood group incompatible with mother, when it takes maternal antibodies from colostrum it recognises the red blood cells as foreign and will coat them for removal, lysing them and causing anemia
66
What does PCV stand for?
Packed cell volume
67
What does a Microhaematocrit measure?
Why is it used often in practice?
Fill in the missing information from the capillary tube showing the results of Microhaematocrit:
The ratio of the volume occupied by packed red blood cells to the volume of the whole blood
Rapid & cheap in house test that gives large amount of information
68
Fill out the missing information (causes that give said results):
Eat lots of carrots = yellow platelets
Haemolysis can instead be an artefacts if rapidly expelled through needle or handled roughly
Fatty diet = grey
69
What is Coulters principle?
How do automated cell counters work?
To establish the number of and identify blood cell populations
A stream of cells passes through an opening between two chambers, across which there is an electrical current. Passing cells disrupt the electrical flow, causing a pulse:
- Pulse frequency = cell number
- Amplitude is proportional to cell volume
70
When discussing canine blood groups what does DEA stand for?
Dog Erythrocyte Antigen
71
What do pen side tests test (snap tests/cards) for?
If the dog has blood type DEA 1.1
72
What dog blood types are there?
DEA 1, 3, 4, 5, 6, 7, 8
and
DAL (dalmations)
(DEA 1 comes in 3 antibodies - 1.1, 1.2, 1.3)
73
What determines blood groups?
What does a combination of blood groups make up?
The antigens expressed on the surface of the erythrocyte
A blood group system
74
What are alloantibodies?
Why is it important to be aware of these?
Specific antibodies directed against erythrocyte antigens (blood types) present in the same species but not in the individual producing the antibody
Important in determining the success or failure of a blood transfusion
75
What causes a transfusion reaction?
The presence of antibodies directed against RBC antigens will reduce the survival of transfused cells (agglutination pr haemolysis of the RBCs) causing a transfusion reaction.
76
How does the presence of antibodies directed against RBCs come about?
Either naturally (in cats), through sensitisation by birth of offspring with a mismatched blood group to the mother (foals - neonatal isoerythrolysis) or produced after sensitisation with a miss-matched blood transfusion (delayed haemolytic transfusion reaction in dogs)
77
Which blood type is most immunogenic in dogs?
DEA 1.1
78
What blood types are the following dogs associated with:
Rotties
Labradors
Greyhounds
Rotties - DEA 1.1 +ve
Labradors - DEA 1.1 +ve
Greyhounds - DEA 1.1 –ve
79
What are the 3 blood groups in cats?
Which are immunogenic?
Which is more common?
A (common)
B (unusual)
AB (rare)
All are immunogenic
None, depends on breeds and countries
80
What will happen if a type B cat receives type A blood?
Massive rapidly occurring intravascular haemolysis of type A donor blood
Can occur following administration of very small volumes of mismatched blood
May be fatal!!
(so high levels of A-alloantibodies in serum)
81
What will happen if type A cats receive type B blood?
Extravascular hemolysis - milder clinical signs
Low half-life of RBCs (2 days +)
PCV will fall to pre-transfusion levels within days of the transfusion
(so low levels of B-alloantibodies in serum)
82
What is unique about AB blood in cats?
Alloantibodies are absent in the serum
83
What does blood group testing or blood typing identify?
The antigen present on the erythrocyte surface it does not determine the presence of alloantibodies
84
What are the 3 types of tests for blood typing or blood group testing?
1. snap tests
2. blood typing cards
3. blood cross matching
85
What do dog snap tests determine?
What about cats?
Dogs - determine if DEA 1.1 positive or negative
Cats - determines if cat is A, B or AB
86
Which species do blood typing cards work on?
How do they work?
Dogs
Antibodies embedded in the paper cause agglutination if there is a positive result, no angulation indicates a negative result.
87
What does cross-matching asses?
What does a minor cross-match detect?
What does a major cross-match detect?
Compatibility between door and recipient
Detects if the donors serum contains any antibodies against the recipients RBCs
Detects if the recipients serum contains any antibodies against the donors RBCs
88
Define the following:
Transfusion
Blood products
Oxyglobin
Transfusion - intravenous therapy with whole blood or blood products
Blood products - blood components (eg. packed red blood cells, plasma)
Oxyglobin - chemically modified haemoglobin of bovine origin
89
What is the purpose of blood transfusions?
To provides support while an underlying cause is found, treatment started or for comfort as end of life support
90
What is the aim of a blood transfusion?
Clinical improvement rather than a normal PCV
(post transfusion PCV dogs - 25-30%)
(post transfusion PCV cats - 20%)
91
When would you need a transfusion?
- due to clinical condition of patient (anaemic patient with signs of cardiovascular compromise)
- PCV <10%
- PCV fallen rapidly to <20% in dogs, <15% in cats
- if there is a haemorrhage during surgery
92
How much should you transfuse? ('rule of thumb')
2ml whole blood /kg body weight raises PCV by 1%
93
What is the calculation based on donor PCV that can be done when working out how much to transfuse?
V= W x F x (PCV1–PCV2)/ PCVd
V= volume to be infused in ml
W=recipient weight in kg
F= 85 (dogs) or 60 (cats)
PCV1= the end PCV you want
PCV2= the current PCV
PCVd= donor PCV
94
What is the dose rate when giving a transfusion?
1 -4 ml/kg/hour
95
Blood cross matching is recommended prior to transfusion for...
... dogs that had a previous blood transfusion
96
Blood typing is essential for...
... all blood transfusions in cats
97
What are the 8 general donor criteria points for blood transfusions?
- Between 1 - 8 yrs
- Healthy, not on any medication
- Good PCV
- Fully vaccinated and wormed
- Good temperament
- Never had a blood transfusion
- Never travelled abroad
- PCV > 35%
98
What will effects will the following % of collection of total blood volume have on the animal:
≤10% of total blood volume
≤20% of total blood volume
≤10% of total blood volume – no adverse effect
≤20% of total blood volume - should not result in clinically significant anaemia provided the donor has a normal PCV at collection (can produce hypovolaemia (lack of blood volume in circulation) in the short term)
99
What are the requirements for cat donors?
- over 4.5kg
- test negative for FIV and FeLV
- females no previous pregnancies, should be neutered
- 40-50 ml collected
- blood group known
100
What are the requirements for dog donors?
- over 25kg
- 450ml collected at pet blood bank
- ideally DEA1.1 negative
101
How much blood do cats generally have?
and dogs?
66ml blood/kg
90ml blood/kg
102
What are the 7 blood groups that horses have?
A, C, D, K, P, Q, U
(lowercase letters ie.Aa, Ab, Ac represent allelic factors)
103
What is the ideal blood donor for horses?
Geldings
104
Which are the most immunogenic blood groups in horses?
Aa, Qa, Ca
105
What is a positive control in ELISA tests?
sample known to contain the antigen or antibody of interest. A positive result from the positive control, validates the test has worked.
106
What is a negative control in ELISA tests?
sample know to not contain protein of interest. Check for non-specific binding and false positive results. Will validate the test works and prove the sample does not contain the specific antigen or antibody
107
What is a common test for canine parvovirus?
SNAP test
108
What is the minimum PCV for a canine blood donor?
>35%
109
What is the acceptable age range for a canine donor?
1 - 8 yrs
110
What specific history is needed from a potential female canine donor?
Had any previous pregnancies
111
What is the maximum total blood volume a canine can donate without serious adverse effect?
20% of total blood volume
112
What pre donation tests must be performed on potential cat donors?
Must be tested for Feline Leukaemia Virus (FeLV) or Feline Immunodeficiency Virus (FIV)
They must also have their blood type tested
113
What is the minimum weight for a cat donor?
4.5 kg
114
TRUE or FALSE!
A first-time canine whole blood or PRC recipient doesn’t need to be crossmatched
True (not best practice though)
115
TRUE or FALSE!
Cats must always receive type-specific blood
True
116
TRUE or FALSE!
There are 7 known canine blood groups
False - there are 8
117
TRUE or FALSE!
Irish Setters have a unique antigen called Iris. D
False - its dilations DALD.D
118
TRUE or FALSE!
There are 3 known feline blood groups
True
119
TRUE or FALSE!
A patient with DEA1.2 negative blood is the ‘perfect’ donor
Flase - DEA 1.1
120
TRUE or FALSE!
Donor blood should be pre warmed to patient body temperature
False - max 37ºC regardless of species
121
TRUE or FALSE
Signs of a transfusion reaction include hypothermia, facial swellings and vomiting
F - pyrexia (fever)
122
A 3-year-old Cocker spaniel called Rolo, is diagnosed with Immune Mediated Haemolytic anaemia (IMHA) and has a PCV of 9% - the vet has asked for a blood transfusion to be performed. Rolo is DEA1.1 positive – what donor could be used?
DEA1.1 positive or negative
123
A 10-year-old Labrador called Henry is admitted as an emergency with a ruptured spleen. Due to extensive blood loss, he requires a blood transfusion – there are no blood typing test kits in the practice due to an ordering error. A known DEA 1.1 positive donor is available, can he have a transfusion?
Yes - first time recipients of blood can receive non-crossmatched blood. BUT once given it will not be possible to identify the recipients blood type and the risk of transfusion reaction is high.
124
The 4-year-old greyhound called Pip has signed up for the practice blood donor list. A blood type test was performed using an Alvedia test kit – what is his blood group?
DEA 1 (1.1/1.2) positive (weak)
125
A 2-year-old German Shepard called Darwin has also been signed up for the same donor list. A blood type test was performed using a Rapidvet H test kit – what is his blood group?
DEA 1.1 -ve
126
A 3-year-old DSH called Felix has been brought in a donor for his bother Jorge, who needs a transfusion following extensive haemorrhage from a hindlimb wound. Jorge has been blood typed as AB.
What is Felix’s blood group, and can he donate to Jorge?
Felix is A and yes BUT only RBCs
127
Hamish is a 10kg Boarder Terrier who has a PCV of 11%. The vet has set his target PCV at 30 per cent. He is receiving his blood donation from Darwin who as a PCV of 40 – How much whole blood does he require?
BV = 80 x 10 x (30-11)/40 = 380mls
128
Mowgli is a 3g DSH who has a PCV of 8%. The vet has set his target PCV at 20 per cent. He is receiving his blood donation from Felix who as a PCV of 38 – How much whole blood does he require?
BV = 60 x 3 x (20-8)/38 = 57mls
