haematology Flashcards
what is haematology
the study of normal and pathological aspects of blood
what do haematologists do
they diagnose, treat and care for people with blood disorders
what are examples of blood disorders
bleeding disorders, haemoglobinopathies, haematological malignancies
what is the volume of blood in the body
5 1/2 litres in a 70kg man (8% of body weight)
females lave 4-5 L whereas males have 5-6 L (due to body size)
what can blood be classed as
connective tissue
what are the physical characteristics of blood
sticky, metaillic taste, high O2 levels blood colour is scarlet but if have low O2 levels colour is dark red (not good), pH is 7.35-7.45
is bright red blood in the arteries or veins
arteries
why does the arteries (instead of veins) have bright red blood
because higher levels of oxygen are found there
what are the functions of blood
protection, transportation, regulation
describe transport as a function of the blood
-it transports O2 and nutrients to body cells.
-transports metabolic waste to lungs and kidneys to eliminate
transports hormones from endocrine organs to target organs
describe regulation as a function of the blood
- maintains temperature by absorbing and distributing heat (by vasoconstriction and dilation)
- maintains pH by using buffers (acid and base) such as bicarbonate
- maintain normal fluid volume (done by plasma proteins which produce colloid osmotic pressure)
describe protection as a function of the blood
-prevents excessive blood loss after injury
- prevents infection as have white bc, antibodies and complement proteins
how and what is the composition of blood
-when take blood out put it in centrifuge
-55% of plasma (least dense)
-1% buffy coat (has leukocytes and platelets)
-45% erythrocytes (most dense)
what type of cells are the most abundant in blood
-red blood cells (erythrocytes)
-males have more RBC than females
what is haematocrit
the % of erythrocytes (RBC) in blood
what’s the volume of leukocytes in blood
1%
what is the function of leukocytes
-defense against disease
-they can leave capillaries by diapedesis which is when you move through tissue spaces by ameboid motion and positive chemotaxis
what is leukocytosis
this is when the white BC count is over 11 x10*9 (means you have an infection so response is normal)
what are the types of leukocytes (phagocytes)
-neutrophils, basophils, eosinophils, monocytes
starting from the most to least dense put the leukocytes in order
-neutrophils
-lymphocytes
-monocytes
-eosinophils
-basophils
(never let monkeys eat bananas)
what is the function of RBC (erythrocytes)
-gas transport such as O2 and CO2
-contributes to blood viscosity
-has a 120 life span
what are the structural characteristics of RBC (erythrocytes)
-biconcave shape (high surface area which allows O2 and CO2 to diffuse quicker)
-anucleate (no nucleus)
-no mitochondria/ ribosomes (no organelles)
how do erythrocytes produce energy
By the embden meyerhof glycolytic pathway which convers glucose into lactate. And anaerobically produces ATP
why do erythrocytes need energy
- to maintain shape
how and why do erythrocytes need to be flexible
it has a red cell membrane which has spectrin (provides flexibility)
why do RBC need flexibility (provided by spectrin)
to change shape
what are RBC filled with
97% of haemoglobin (for gas transport)
what is the structure of haemoglobin
-binds and carries O2
-globin is a large protein made of 4 polypeptide chains (2 alpha and 2 beta chains)
-RBC has 200-300 million hae (males have more than females)
haemoglobin structure
-haem binds to a globin chain (gives red colour)
-haem is made of protoporphyrin ring that’s made up of 4 pyrrole rings
- there’s iron (gives colour) in the middle which binds to 1 O2
-each hae transports 4 O2
what’s oxyhaemoglobin
produces ruby red substance
what happens when O2 is loading in lungs
-oxyhaemoglobin is produced
-O2 is abundant (lots) in lungs
-hae picks up 4 O2 molecules
what happens when O2 is unloading in tissues
-hae releases O2 into tissues
-deoxyhaemoglobin is produced (dark red)
what happens to oxygen’s affinity when O2 binds to one haem grp
affinity increases
what is co-operativity
causes sigmoidal s shape when oxygen binds to haemoglobin. the change in shape makes it easier for next O2 to bind (that’s why affinity increases)
what type of structure does haemoglobin have
quaternary structure
where is iron located
in the middle of each globin subunit (2 beta and 2 alpha)
what type of haemoglobin do foetus’s have
2 alpha and 2 gamma chains which have higher affinity
how much red blood cells do adults produce every second
2.3 million
how much red blood cells do adults produce every minute
138 million
what type of stem cells does every cell in the blood come from
haematopoietic stem cell
where are haematopoietic stem cells located
in the bone marrow
what do you call the formation of red cells
erythropoiesis
what is the name for the formation of granulocytes and monocytes
myelopoiesis
what is the name for the formation of platelets
thrombopoiesis
what is bone marrow
bone marrow is the active site, it has great blood supply (important for transportation)
what can multipotential haematopoietic stem cells (hemocytoblast) be split into
common lymphoid progenitor and common myeloid progenitor