Haematology Flashcards
What are the functions of blood?
Transport of gases, waste products, hormones, blood cells etc. Maintains body temp Controls pH Removes toxins Regulates blood clotting Regulates body fluid electrolytes
What are the constituents of blood?
Plasma ~ 55%
Erythrocytes (RBCs) ~ 45%
Leukocytes (WBCs)
Thrombocytes (platelets)
What different types of blood collection are there and when are they used?
Capillary blood collection - when only few drops required - ear lobe, finger prick
Venous blood collection - when large amount of blood needed - median cubical veins, cephalon veins
Define Haematocrit
The % of total blood volume occupied by erythrocytes
What is the average normal haematocrit for a male and female?
Female - 42%
Male - 45%
What is the normal Hb range for male and females?
Male - 14-16 g.100ml-1
Female - 13-15 g.100ml-1
Define Anaemia
When you don’t have enough RBCs or Hb to meet your body’s need, so it impedes O2 delivery
Define Polycythemia
Having a high conc of RBCs in your blood, so you have higher blood viscosity and so high blood pressure
What is total Hb mass? And what is it a key determinant of?
The absolute mass of circulating Hb in the body.
It is a key determinant of max O2 uptake
How can VO2 max be increased?
Balanced increase in tHb mass and plasma volume which results in increased cardiac output. This is achieved through endurance training.
Increase in Hb conc via a increase in tHb mass and reduced or unchanged plasma volume. Achieved by altitude training or blood doping.
What is hypervolemia? And why does it occur in exercise training?
A net expansion of total body water and solutes - so you have a greater % of plasma in blood.
It occurs due to increased water intake and decreased urine output while exercising.
Why could hypervolemia be advantageous?
There is greater body fluid for heat dissipation and thermoregulatory stability.
Larger vascular volume and filling pressure for greater cardiac stroke volume and so lower HR during exercise.
How would you calculate change in blood volume (post)?
(Hb pre x BV pre) / Hb post
Assume BV pre is 100ml
How would you calculate change in cell volume (post)?
BV post x Hct post
In mL
How would you calculate % change in plasma volume?
((PV post - PV pre) / PV pre) x 100
How do you calculate sweat rate?
((Pre body mass x post body mass) + fluid intake) / hours exercised
If urinated during exercise assume fluid loss of ~ 0.3L and subtract
What affects Hb’s ability to bind to O2?
PO2 and number of free O2 binding sites
How is the increasing demand for O2 met during exercise?
Muscle blood flow is increased and O2 unloading is improved
Why does the oxygen dissociation curve shift to the right during exercise?
Exercising muscle cells release H+, CO2 and lactate into capillaries and the temp increases. The blood entering these exercising muscle capillaries is exposed to this which causes a decrease in Hb-O2 affinity.
What is pulse oximetry?
And what’s the normal level?
A method of measuring your O2 saturation or O2 levels in arterial blood. Normal levels 94-99%
What is near infrared spectroscopy? And what’s the normal level?
A technique to measure tissue O2 saturation.
~ 60-70% in skeletal muscle
How is lactate formed?
In anaerobic conditions, pyruvate is converted to lactic acid. This dissociates quickly to release H+ ions and lactate.
Why might you measure blood lactate?
To help monitor/modify training as lactate threshold is a good predictor of performance.
It’s a good indicator of training adaptations - the higher the lactate threshold the better.
Correlates with endurance performance.
Helps identify optimal training status.
Why might you take a neutrophil and white blood cell count?
Neutrophils and WBCs are markers of infection.
An increased neutrophil count indicates a bacterial infection, an increased lymphocyte count indicates a viral infection.
How might you measure muscle damage using the blood markers?
Following endurance training there is an increase in plasma CK activity and plasma LDH activity. These protein levels can be analysed via ELISA test.
What inflammatory marker could you measure post exercise from the blood?
IL-6
