Structure and Function of blood Flashcards
What is blood?
Specialised fluid (technically a tissue) composed of cells suspended in a liquid (plasma)
Name 3 types of red blood cell?
Red blood cell
White blood cell
Platelets
What are purposes of the 3 types of blood cell?
Fight infection
Transport oxygen
Prevent bleeding
What is the production of blood cells termed?
Haemopoiesis
Haematopoiesis
What are blood cells formed from?
Small pool of pluripotent stem cells
Where does haematopoiesis happen in the embryo?
Yolk sac then liver
3rd to 7th month = spleen
Where does haematopoiesis occur at birth?
Mostly bone marrow, liver and spleen when needed
Where does haematopoiesis occur from birth to maturity?
Number of active sites in bone marrow decreases but retain ability for haematopoiesis
Where does haematopoiesis in an adult?
Bone marrow of skull, ribs, sternum, pelvis, proximal ends of femur
How many red blood cells are needed per minute?
100 million
How many neutrophils are needed per minute?
60 million
How many platelets are needed every minute?
150 million
In what state do most stem cells sit in?
Quiecent
How does a neutrophil form?
Myeblast to promyelocyte to myelocyte through metamyelocyte forms eventually to band forms and to neutrophils
What do granulocytes contain and name 3 examples?
Granules.
Eosinophils
Basophils
Neutrophils
Describe the structure of a neutrophil?
Segmented nucleus (polymorph) Neutral staining granules
Describe the function of a neutrophil?
Short life in circulation (transit to tissue)
Phagocytose invaders
Kill with granule contents and die in process
Attract other cells
Increase of body stress
Describe the function of Eosinophils?
Usually bi-lobed
Bright orange/red granules
Describe the function of eosinophils?
Fight parasites
Involved in hypersensitivity reactions
often elevated in patients with allergic conditions
Describe the structure of basophils?
Infrequent in circulation
Large deep purple granules obscuring nucleus
What is the function of basophils?
Circulation version of tissue mast cell
Mediates hypersensitivity reactions
Fc Receptors bind IgE
Granules contain histamine
Describe the structure of monocytes?
Large single nucleus
Faintly staining granules, often vacuolated
Describe the function of monocytes?
Circulate for a week and enter tissues to become macrophages
Kill and present antigen to lymphocytes
Attract other cells
What lives longer, a neutrophil or a basophil?
basophil
What is the structure of a lymphocyte?
Mature, small with condensed nucleus and rim of cytoplasm
Activated (often called atypical) large with plentiful blue cytoplasm extending round neighbouring red cells on the film, nucleus more “open” structure
Describe the function of lymphocytes?
Numerous types and functions
Cognate response to infection
Brains of the immune system
How is immunophenotyping done?
Expression profile of proteins (antigens) on the surface of cells
How are bio-assays measured?
Culture in vitro and show lineage of progeny in different growth conditions
What 4 ways can you examine the haemopoietic system?
Look at peripheral blood
Look at bone marrow
Specialised tests of bone marrow
Look at other sites of relevance to blood i.e. hepatomegaly etc.
Where is a common site for bone marrow aspiration and biopsy?
Posterior iliac crests
