A & P - Blood and haemostasis Flashcards
what is blood composed of?
plasma and cells
which cells can be found in the blood and what are their function?
erythrocytes - transport oxygen and carbon dioxide
leukocytes - defence immunity
platelets - blood cloting
what would happen if there was a high blood volume?
high blood pressure
name two ways of sampling blood
heal/thumb prick
venepuncture - from vein if large amount needed
what is a haematocrit test and what is it used for?
blood is centrifuged, good for accessing % of RBC’s
how much blood does the average adult have?
4-6l
name the percentages of each component of blood
plasma - 55%
cells - 45%
leukocytes and platelets - 1%
what does blood plasma contain?
water - universal solvent electrolytes - 90% Na+ hormones plasma proteins- antibodies, clotting organic waste products
name some (3) blood plasma proteins
albumin
fibrinogen and clotting factors
globulins (antibodies)
name some organic waste products found in blood plasma
urea
creatinine
uric acid
where is albumin produced and what is its function in blood plasma?
liver
influences - BP, flow and fluid balance
where are fibrinogen, clotting factors and globulins (antibodies) produced?
fibrinogen and clotting factors - liver
globulins (antibodies) - plasma cells
name the formed elements of blood
monocytes platelets lymphocytes - large and small neutrophils basophils eosinophil erythrocytes
what is the life scan of an erythrocyte?
120 days
what does an erythrocyte produce from CO2 and water?
carbonic acid
how many haemoglobin does a RBC contain?
280 million
describe the make up of a haemoglobin
1 globin made of 4 polypeptide chains and 4 pigment hemes
which area of the haemoglobin does oxygen bind to?
the iron ion of the heme
does foetal haemoglobin have a higher or lower affinity to oxygen than adult haemoglobin?
higher
what value id the haemoglobin concentration of blood measured in?
g/dl
what is a normal RBC count for women and why is it lower than in men?
3.8 - 5.8 * 10*12 per litre
periods
what is a normal RBC count for men and why is it higher than in women?
4.5 - 6.6 1012 per litre
androgens stimulate RBC production
what is the formula for normal erythrocyte sedimentation rate for men and women?
men - age/2 or lower
women - age+10/2 or lower
what would increase the rate of erythrocyte sedimentation?
cancer
rheumatoid arthritis
kidney disease
infection
what is erythrocyte sedimentation rate?
time taken for RBC’s to settle
name two types of leukocytes (white blood cells)
granulocytes
agranulocytes
name three granulocytes and % found in WBC’s
neutrophils - 60-70%
eosinophil - 2-4%
basophils - <1 %
name two agranulocytes and % found in WBC’s
lymphocytes - 25-35%
monocytes - 3-8%
name some conditions that neutrophils would control and explain how they do this?
bacterial infections
haemorrhage
appendicitis
work by phagcytosis
name some conditions that eosinophil’s would control
parasitic infections
asthmas
allergies
name some conditions that basophil’s would control
haemolytic anaemia
chicken pox
name some conditions that lymphocytes would control
chronic infections
name some conditions that monocytes would control
malaria
typhoid
what is the term used to describe an increase in WBC’s?
leukocytosis
what are thrombocytes?
platelets
what are platelets formed from?
fragments of larger cells called megakarocytes
what are the functions of platelets?
form a temporary platelet plug
dissolve old blood clots
attract WBC to site of inflammation - to phagocytise bacteria
what do platelets secrete?
clotting factors
factors for endothelial repair
vasoconstrictors in broken blood vessels
what is the term used for blood cell production?
haemopoiesis
name two tissues that produce blood cells in the womb
yolk sac (embryo) liver, spleen (until birth)
name two tissues that produce blood cells after birth and say which types are produced
red blood marrow - RBC, WBC, platelets
lymphoid tissue - WBC production and maturation
what stimulates RBC production in the kidney due to hypoxia?
erythropoietin
what is the term used for RBC production?
erythropoiesis
how many RBC are produced per second?
2.5 million
how many days does it take for a RBC to mature?
3-5 days
what happens during the maturation of RBC’s?
reduce in size
synthesis haemoglobin
lose nucleus
what is the name for a young RBC?
reticulocyte
how and where are RBC recycled?
where - liver and spleen
iron stored
heme removed in bile and faeces
globin hydrolysed to free amino acid
what is hypoxemia and what are the causes?
inadequate O2 transport caused by lung disease, high altitude, exercise, bleeding
what is needed for RBC production?
iron - absorbed in blood travels to bone marrow, muscle, all cells (liver stores iron)
B12 and folic acid
what causes anaemia?
decreased RBC or haemoglobin synthesis decreased nutrition increased blood loss RBC destruction (haemolytic) RBC deformed (sickle cell)
what causes diet induced anaemia?
reduced intake of : iron, B12, folic acid
what is macrocytic and microcytic anaemia?
macro - RBC too large
micro - RBC too small
what causes pernicious (microcytic) anaemia?
vitamin B12 deficiency
what is haemorrhagic (normocytic) anaemia?
after haemorrhage
what is haemolytic anaemia?
malaria
reduced no. RBC
what is aplastic anaemia?
bone marrow problems
leukaemia
what is haemostasis?
no bleeding - no thrombosis
balanced interaction of blood cells, vasculature, plasma proteins and low molecular weight substances
what is primary haemostasis?
temporary platelet plug
what is secondary haemostasis?
coagulation
stable clot
name the three stages of control of bleeding following vessel injury
- vascular spasm
- platelet plug formation
- blood clotting
describe what happens during vascular spasm following a vessel injury
injury prompts constriction of vessel - triggered by pain receptors
platelet chemical release (serotonin)
describe what happens during platelet plug formation following a vessel injury
1st platelet adhesion - stick to rough surface of vessel
2nd platelet aggregation - platelets release substances to attract more platelets
describe what happens during coagulation following a vessel injury
clotting factors in plasma (thrombin) causing a chemical cascade reaction to activate fibrinogen then fibrin
what is the difference between extrinsic and intrinsic coagulation pathways?
ex - damage outside blood vessel
in - damage inside blood vessel
which coagulation pathway is slower acting?
intrinsic
which factors do intrinsic and extrinsic coagulation pathways use?
ex - factors external to blood clotting factors
in - blood clotting factors
name the six clotting factors
I - fibrinogen II - prothrombin III - thromboplastin IV - Ca2+ VIII - anti-haemophiliac factor A IX - Christmas factor
how long doe it take for the extrinsic clotting mechanism to begin?
15 secs
how long doe it take for the intrinsic clotting mechanism to begin?
3-6 mins
describe how a blood clot is stopped by the body
platelets produce chemicals which inhibit clotting
heparin in blood inhibits clotting
clot dissolves by plasmin
what is the term used for a clot being dissolved?
fibrinolysis
what is plasmin?
fibrin dissolving enzyme
name two natural anticoagulants found in blood
anti-thrombin
heparin (both block action of thrombin)
name 4 ways in which haemostatic function can be tested
blood count
blood film
bleeding time
INR
what are antigens A and B?
inherited glycoproteins on RBC membrane
do people with blood type O have antigens on their RBC’s?
no
what happens if blood with incompatible antigen’s was given?
cause agglutination (clumping) of blood
what is your blood group determined by?
the antigen (A & B) or lack of (O)
what is a resus group?
the positive or negative part of the blood group
what does resus + and - mean?
+ have D antigen
- have no D antigen
what can happen if the wrong blood group is given during a blood transfusion?
agglutination - blockage of vessels
haemolysis - free Hb block kidney tubles - DEATH
which blood should be given in an emergency and what observation should be made?
O(-) as no antigens
monitor: temp, BP, rash, pain, kidneys
during a blood transfusion which blood could a blood group A person receive?
A or O
during a blood transfusion which blood could a blood group AB person receive?
A, B, AB or O
during a blood transfusion which blood could a blood group O person receive?
O only
if the blood to be given is Rh + who can receive the blood
only someone who is Rh+
if the blood to be given is Rh - who can receive the blood
anyone + or -
what would happen in a first and second pregnancy if the mother was Rh- and the baby was Rh+?
1st pregnancy - mother exposed to Rh+ blood of baby, mother produces anti D antibodies
2nd pregnancy - anti D antibodies attack blood of baby
how is haemolytic disease of the new-born treated?
with anti D immunoglobin
what are the results of untreated haemolytic disease of the new-born?
severe anaemia
toxin brain syndrome
rejection of foetus
what is thrombosis?
formation of thrombus in vessel
what causes a thrombosis?
pooling of blood in veins (DVT) damaged vessels (atherosclerosis)
how does a thrombus form?
fibrin framework - traps platelets and other cells
attaches to vessel wall - impede blood flow and reduces profusion of tissue
what plays a major role in venous thrombosis?
coagulation
what plays a major role in arterial thrombosis?
platelet aggregation
what is an embolus?
fragment or whole thrombus detached from vessel wall
what does an embolus do and what can it cause?
blocks small blood vessels
causes: pulmonary embolism, myocardial infarction or stroke
