Blood & Blood Groups Flashcards
Where in the body would you find the most blood at anytime?
Small veins & venules
What are the functions of blood?
Delivery of nutrients. Transport of gases for gas exchange. Transport of metabolic waste. Carriage of hormones, enzymes, drugs and their metabolites. Immunological role. Thermoregulation.
Where in the body would you find the least amount of blood at anytime?
Capillaries
What type of tissue is blood?
Specialised connective tissue
What are bloods 2 components that make it a connective tissue?
Plasma (non-cellular matrix) Blood cells (formed element)
Define haematocrit?
The fraction of the total blood volume that is occupied by the red cells.
How would you calculate a haematocrit?
Centrifuged blood sample
What is a normal haematocrit value?
35% - 50% (males upper end/ females lower end)
What effect would anaemia have on haematocrit values?
Lower than normal
What effect would polycythaemia have on haematocrit values?
Higher than normal
What does plasma contain?
90-95% water, 5-10% solutes
What is the pH of plasma?
7.35-7.45
What does plasmas solutes contain?
Salts (electrolytes) - sodium, potassium, calcium, chloride & bicarbonate
What products ate found in plasma?
Salts (electrolytes), glucose, amino acids, urea & other small molecules, hormones, plasma proteins (albumins, globulins, fibrinogen)
Name all 3 plasma proteins?
Albumins, globulins, fibrinogen
What are the functions of plasma proteins?
Own individual functions. Binding, clotting, antibodies.
Maintain fluid balance between plasma & interstial fluid.
Healthy correct level of plasma proteins in the capillary blood.
What is fluid removed from interstial space by?
Lymphatic drainage vessels
What happens if plasma protein levels low?
More fluid than normal leaves the blood the lymphatics are unable to carry all of this fluid away.
What is oedema?
The accumulation of excessive fluid in the tissues.
What are the clinical names for red & white blood cells & platelets?
Red cells- erythrocytes
White cells- leukocytes
Platelets- thrombocytes
What is the name of the stem cells in bone marrow that blood derives from?
Haemotopoietic tissue
How many red blood cells per litre are there in a healthy person?
4.5-6.5 million million per litre
What are the properties of red blood cells?
Biconcave disc, non-nucleated in adult form, no mitochondria, contain haemoglobin (Hb)
What are the properties of Hb?
Iron containing protein.
Binds avidly to oxygen to form oxyhaemoglobin.
Each Hb molecule can combine with 4 oxygen molecules.
What would oxygen saturation be if all 4 Hb molecules combined with 4 oxygen molecules?
100% saturation
What is a normal Hb concentration?
11-18g/100ml (dL) or 110-180g/ litre (may be less in pregnancy
What is the process of red blood cell formation called?
Erythropoiesis
What stimulates erythropoiesis?
Hormone called erythropoietin thats made in the kidneys.
Where is erythropoietin made?
Kidneys