Blood Flashcards
1
Q
Roles of blood?
A
Carries - nutrients to tissue; O2 from lung to tissue; CO2 from periphery to lung; hormones from endo. glands to target organs; waste from tissues to kidney -> excretion
Regulates - ion composition of interstitial fluids via diffusion; pH by neutralising acid (eg lactic acid)
Restricts - fluid loss at injury sites
Defends - immune sys (toxins/pathogens)
Stabilises - body temp
2
Q
Composition of blood…?
A
RBC’s
WBC’s
plasma
platelets
3
Q
Define haematocrit
A
Proportion of cells in blood relative to plasma - PCV & buffy coat
4
Q
What does PCV measure and indicate?
A
Health of animal
Number of erythrocytes (RBC) in blood stream
Also indicates oxygen delivery capacity
5
Q
Normal animal PCV/TP?
A
~40% & ~60%
6
Q
What would PCV be in anaemic animal?
A
low
7
Q
What would PCV be in dehydrated animal?
A
high
8
Q
PCV response to training & fitness?
A
increases
9
Q
Haematocrit of: anaemic, polycythaemic, dehydrated animals?
A
anaemic ~ 30%
polycythaemic ~ 70%
dehydrated ~70% (but less TP)
10
Q
Blood volume, viscosity, temp, pH?
A
BV - 8-10% of lean body weight
Viscosity - 5 times that of water
temp - slightly above normal body temp
pH - between ~7.35 - 7.45
11
Q
Different types of acidosis…?
A
Diabetic acidosis
Hyperchloraemic acidosis
Lactic acidosis
12
Q
What is diabetic acidosis?
A
accumulation of ketone bodies during uncontrolled diabetes
13
Q
What is hyperchloraemic acidosis?
A
Excessive loss of sodium bicarb. from severe diarrhoea
14
Q
What is lactic acidosis?
A
Accumulation of lactic acid (prolonged lack of oxygen due to shock, heart failure; prolonged exercise; seizures; hypoglycaemia; alcohol; liver failure)
15
Q
Different types of alkalosis…?
A
Respiratory alkalosis
Metabolic alkalosis
Hypochloraemic alkalosis
Hypokalaemic alkalosis
16
Q
What is respiratory alkalosis?
A
Altitude or disease -> decreased O2 -> hyperventilation -> low CO2 -> resp. alkalosis
17
Q
What is metabolic alkalosis?
A
excess bicarbonate in blood
18
Q
What is hypochloraemic alkalosis?
A
Extreme lack or loss of Cl (possibly due to prolonged vomiting)
19
Q
What is hypokalaemic alkalosis?
A
Extreme lack or loss of K (possibly due to diuretic meds)
20
Q
What are the formed elements of blood?
A
Erythrocytes (no nuclei)
Leukocytes
Platelets (no nuclei)
21
Q
Define haematopoiesis
A
formation & dev. of all formed elements via proliferation & differentiation of bone marrow stem cells
22
Q
Examples of circulating chemical messengers that regulate stem cells to enable specific blood cells to develop
A
erythropoeitin
interleukin-2
23
Q
T or F - Erythrocytes (RBC) are the most abundant cells in the blood
A
True
24
Q
7 billion RBC in which animal?
A
cow
pig
dog
25
10 billion RBC in which animal?
horse
26
11-12 billion RBC in which animal?
sheep
27
Erythrocyte characteristics
specialised for O2 transport
shape => larger area:volume -> faster O2 exchange cell membrane; greater H2O uptake due to osmotic swelling without rupture of cell membrane
Shapes & sizes vary (sheep & goats - smallest; dogs - largest)
28
What is erythropoiesis?
Formation of RBC
29
Where does erythropoiesis occur in the foetus?
bone marrow
liver
spleen
lymph nodes
30
Where does erythropoiesis occur in larger skeleton?
red bone marrow - found mainly in flat bones & cancellous (spongy) material of long bones
31
T or F - In severe blood loss, body converts yellow marrow back to red marrow to increase blood cell production
true
32
What are haematopoietic growth factors (HGF's)?
Cytokines -> influence dev. of particular blood cell types
33
HGF that stimulates erythrocyte production?
erythropoietin (EPO)
34
Where is EPO released, where does it act, and what does it do?
Kidney -> stem cells in bone marrow -> increase prod. of RBC -> increase O2 delivery to kidneys
35
-ve feedback of EPO by ...?
RBC's
36
Draw & learn RBC production
slide 25
37
What are the stages of RBC dev?
rubriblast -> basophilic rubricyte (day 2) -> polychromatophilic rubricyte (day 3) -> metarubricyte -> reticulocyte -> erythrocyte (day 5-7)
38
What are the 3 specialised pigments that aid RBC's in transporting O2 & CO2 around the body?
haemoglobin (Hb)
carbonic anhydrase
myoglobin (muscle haemoglobin)
39
Characteristics of haemoglobin (Hb)...?
1/3 RBC content
contains 4 red porphyrin pigments (heme)
appears reddish when O2 present; blue-purple when O2 not present, acidified or CO2 present
40
How does Hb facilitate O2 & CO2 transport?
Each heme group contains Fe atom that combines loosely with O2 molecule -> transports O2 as oxyhaemoglobin & CO2 as carbinohaemoglobin
41
Explain removal of erythrocytes
Occurs after 3-4 months in circulation
10% haemolyse in circulation -> cell debris removed by macrophages in liver, spleen, bone marrow, lymph nodes
RBC's broken down -> haemoglobin degraded & Fe seperated -> excreted in bile or urine
42
What is haemolysis?
Breakdown of RBC's & release of haemoglobin into plasma
| Caused by bacterial toxins, snake venom, blood paracites, hypotonic substances, chemical substances
43
Reddish urine indicates what?
haemoglobin in urine (haemoglobinuria)
| Caused by: Leptospirosis, tick fever (cattle), perturient haemoglobinuria
44
What is haemoconcentration?
low plasma relative to RBC
high [RBC] in circulating blood
Low vit A in pigs - dengue virus
45
Characteristics of leukocytes...?
```
Less numerous than RBC (~1000:1)
mostly have functions in tissues
circulatory system for transport only
have nucleus & cytoplasm
Only fully functional cells in blood
```
46
Name the leukocytes
Granulocytes - neutrophils, eosinophils, basophils
| Agranulocytes - monocytes, lymphocytes
47
Granulocytes...
formed in red bone marrow
neutrophils 1st line of defense -> site of bacteria via vessel walls & ENGULF bacteria
Number increases when acute infection present
neutrophils greatest no. of WBC's
48
Granulocytes (eosinophils)...?
normally low
increase in certain chronic conditions (eg. parasite infections, allergic conditions); and allergic reactions
primary function - DETOXIFICATION
49
Granulocytes (basophils)...?
rare in normal blood
release histamine & heparin
mainly involved in inflammatory reactions in tissue
50
Agranulocytes (monocytes)...?
engulf foreign matter (bacteria)
active in less acute infections (TB)
transformed into macrophages
51
Agranulocytes (lymphocytes)...?
Form Ab's in response to Ag's (basis of vaccination)
| High number indicates infection
52
Types of lymphocytes...?
B lymphocytes - humoral immunity
T lymphocytes - cell-mediated immunity
Natural Killer NK cells - lyse virus-infected host cells
53
Platelets charachteristics...?
rod-shaped oval disks - no nuclei
important in CLOTTING
originate from megakaryocytes - bone marrow (adult mammals)
half diameter RBC's
9-12 day life span before phagocytosis (spleen)
thrombocytes (non-mammals)
54
3 phases of the blood-clotting cascade...?
vascular phase
platelet phase
coagulation phase
55
Vascular phase...?
~30 mins
damage -> contraction SM fibres & vasoconstriction (SNS)
other factors & hormones released -> endo cells become sticky
56
Platelet phase...?
attach to sticky endo membranes -> platelet plug
KEY SUBSTANCES - von Willebrand factor (protein) & ADP
platelets contain actin & myosin proteins
57
Coagulation phase...?
FIBRIN (protein) in plasma -> blood coagulation
| Formation of fibrin clot requires sequence of reactions
58
B lymphocytes (B-cells)...?
Humoral immunity
| transformed -> plasma cells & secrete Ab's -> destroy (directly/indirectly) foreign material
59
T lymphocytes (T-cells)...?
Cell-mediated immunity
T-cells make contact with cells bearing foreign Ag
Types: cytotoxic T-cells -> destroy virus-invaded cells; helper T-cells -> secrete cytokines for humoral response
60
Natural killer (NK) cells...?
spontaneously & non-specifically lyse infected host cells
| numbers only increase during specific immune response
61
Explain differential White Blood Cell counts
Indicates % of each type of WBC in blood sample
Different leukocytes -> different functions & responses to infection or disease
Can be useful for diagnostics
Differentials taken over time useful to evaluate response of animal to infection or disease
62
Platelet functions...?
BLOOD CLOTTING -> decrease blood loss from site of injury by adhering to vessel walls & each other -> haemostatic plug -> thrombus (clot) -> occludes opening in vessel
63
What are the sequences of reaction in the coagulation phase of blood clotting?
Coagulation cascade
Coag. factors activated via 3 pathways
1. extrinsic - begins outside blood stream in vessel wall due to tissue damage
2. intrinsic - begins inside bloodstream
3. common pathway - extrinsic & intrinsic pathways meet
64
Plasma properties...?
55-77% of blood
| fluid portion of blood (92% water, 8% other sub's - mainly proteins, also glucose, lipids, hormones + mineral salts)
65
Organ responsible for maintaining constant proportions of water & other constituents of plasma?
Kidneys
66
Role of plasma proteins?
```
Transport of substances
BP maintenance (altering viscosity of blood)
immunity (gamma globulins)
maintain osmotic pressure of blood
buffer (acid-base balance)
Suspension stability of RBC's
clotting
```
67
Which molecules & drugs do plasma proteins also transport around the body?
```
Carrier molecules for:
Nutrients (Ca, P, Fe, Cu, lipids, fat-soluble vit's, AA's)
Hormones (thyroxine, steriods)
Cholesterol
Heme
Enzymes
Barbituates (anaesthetics)
Sulfonamides (type of antibiotic)
```
68
Name the plasma proteins...
Albumin
Globulins
Fibrinogen
others
69
A bit about Albumin...?
~60% plasma proteins
MAIN regulator of blood osmotic pressure
bind irreversibly & transport main chemicals in blood (FFA, bilirubin, thyroid hormones, some steroids)
70
A bit about globulins...?
~35% plasma proteins
enzymatic functions
Contain gamma globulins stimulated by Ag's for immune response
71
A bit about fibrinogen...?
Synthesised by liver
| essential for clotting
72
What is serum?
plasma - fibrinogen & most clotting factors
| contains antibodies that animal may have formed
73
A bit about lymph...?
lymphatic system - extensive network of one-way vessels
Made up of loss of protein & fluid from capillaries
contains lymphocytes, inorganic salts, glucose, proteins, N substances
intestinal lymph - milky coloured
Lymphoid tissue (lymphocytes) - defence against infection
74
A bit about serous fluids...?
housed in body cavity (peritonial, pleural & pericardial fluid)
thin film decreases friction between surfaces
inflamm. or infection of serous membranes -> increased prod. of serous fluids causing:
pleutitis, peritonitis, pericarditis
75
What is anaemia?
- Numbers of RBC's or haemoglobin below normal levels
- Deficient blood formation (poor nutrition, low Fe, Cu, vit's, AA's)
- Blood loss (wounds, parasites (worms))
76
What causes anaemia at the cellular level?
- Deficient secretions of INTRINSIC FACTOR (stomach) -> low vit B absorption -> pernicious anaemia
- If blood cells haemolysed faster than new ones can replace them
- If RBC's FAIL TO MATURE normally
77
Cascade of events of anaemia...?
Reduces O2 carrying capacity of blood -> decreased [RBC] -> decreased blood vicosity -> increased blood flow -> hypoxia at tissue level -> heart stimulated to pump faster to deliver more O2
When animal exercised hard, heart cannot supply enough O2 -> heart efficiency decreases -> may lead to heart failure
78
Blood group classification is based on what?
Presence or absence of inherited antigenic substances on RBC surface
79
Blood group antigens can be...?
proteins
CHO's
glycoproteins
glycolipids
80
What are human antigens made of in the ABO blood group?
Sugars - based on DNA & type of enzymes they have present
81
What are human antigens made of in the rhesus (Rh) blood group?
Proteins
82
What is the biological importance of blood groups?
- transports bio. important molecules across red cell membrane
- receptors of external stimuli & cell adhesion
- regulators of complement sys. (proteins in blood regulate dev. inflamm.)
- enzymes
- anchor red cell membrane to cytoskeleton
- providers of extracellular CHO matrix -> protects from mechanical damage & microbes
83
How many recognised blood group antigens?
285 (245 classified into one of 29 blood group systems)
84
Most common human blood groups?
```
ABO & Rh D (most commonly recognised)
A
B
AB
O
Rh D-positive
Rh D-negative
```
85
What are the antigens on RBC's/antibodies in plasma in different blood types...?
Group A - A/anti-B
Group B - B/anti-A
Group AB - A & B/ no Ab's
Group O - no antigens/anti-A & anti-B
86
Can blood group be changed in individual?
Usually same blood group for life
May change with addition or suppression of antigen (infection, malignancy, autoimmune disease)
Bone marrow transplant
