Haematology Flashcards
How many litres of blood does the average adult have?
5
what percent of a human’s weight is blood?
7
What sort of tissue is blood?
a fluid connective tissue
What’s blood made up of?
45% cells
55% plasma
What’s plasma made up of?
92% water
7% plasma proteins
what’s plasma’s function?
transport :
organic and inorganic molecules
formed elements
heat
What’s Hemopoisesis?
the production of all cells in the blood
what’s erythropoiesis?
the formation of red blood cells
what’s an erythrocyte?
a red blood cell
How does a hemocytoplast become an erythrocyte?
Hemoctyoblast (stem cell)–> proerythroblast (committed cell) –> early erythroblast (ribosomes are sythesised)–> late erythroblast (hemoglobin accumulates)–> normoblast (nucleus is ejected)–> reticulocyte–> erythrocyte
what’s required for erythrocyte formation? (6)
- Erythropoietin (EPO)
- Iron
- Vitamins B12
- B9 (folic acid)
- intrinsic factor
- Amino acids
What shape are red blood cells?
biconcave discs
Where does erythropoiesis happen in the foetus?
early in the yolk sac then in the liver and spleen then bone marrow
where does erythropoiesis happen in an infant?
all bone marrow
where does erythropoiesis happen in an adult?
only red bone marrow e.g. ribs, vertebrae etc.
if there’s problems with this they can be produced in all bone marrow, liver and spleen
Give 3 properties of RBCs
- biconcave disc shape
- can bend/fold- highly flexible
- can stack
- strong and rigid cytoskeleton
- no organelles- just haemoglobin
what’s an RBCs life span?
limited, average of 120 days
where are RBCs broken down?
in the spleen
what breaks down RBCs in the spleen?
macrophages
What’s Haemoglobin broken down into?
Haem and Globin
what is Haem?
iron containing compound
What can the iron from haemoglobin be used for?
making more RBCs or broken down into bilrubin which can be excreted
what can the globin element be broken down into?
amino acids which can be used for proteins or new RBCs
What’s Hypoxia?
low blood-oxygen level
