Introduction to Blood Flashcards
(32 cards)
List the qualities of blood that allows it to provide a means for sampling body tissues and fluids.
It is largely homogenous
It is in equilibrium with tissues
Shows reactive responses in disease states
List the components of blood.
Blood cells
Plasma proteins
Products of metabolism - metabolites, hormones etc.
Leakage from tissue cells - enzymes, other cytoplasmic constituents
May contain pathogens
What is haematology concerned with?
Cells of the blood
Haemostasis - control of bleeding & clotting
Name what the haematology laboratory assessment of blood cells involves.
Cell counts - quantitative
- red cells: concentration, size, contents
- leucocytes: concentration
Blood film examination to:
- check morphology - qualitative evaluation
- confirm cell count data - quantitative check
Specialized tests
Name the normal lecuocytes and reticulocytes.
Band forms and melanocytes Neutrophil Eosinophil Basophil Monocyte Lymphocyte Reticulocytes
What is the purpose of an Automated Haematology Analyser?
Provides an automated count of cells
Single cells assessed by laser beam (cell size, cytoplasmic/nuclear activity, detection of peroxidase enzyme)
Name the parameters of RBCs that are usually examined.
Red cell concentration (RBC) Haemoglobin (Hb) Haematocrit (Hct) Mean cell volume (MCV) Mean cell Hb (MCH) (Mean cell Hb conc.)
Define reference range/interval for a population.
The range of values present in 95% of healthy individuals of a specified population, for a test.
Name the factors affecting reference ranges for blood cells.
Developmental age
Gender
Psychological changes - pregnancy, high altitude, climate
Ethnic (genetic) differences
Define anaemia.
Reduced haemoglobin for age, gender, geography/ethnicity.
Indicates reduced ability to transport oxygen in blood
Name the different cell size types relating to anemia.
Microcytic
Macrocytic
Normocytic
Name the different cell concentrations of Hb relating to anaemia.
Hypochromic
Normochromic
Define microcytic hypochromic anaemia.
Small under filled red cells
Define normochromic normocytic anaemia.
Normal red cells
Define macrocytic anaemia (normochromic).
Large red cells
Name features of microcytic hypochromic anaemia.
Iron Deficiency
Pencil cells and target cells
Erythroblasts show reduced Hb production & no stainable iron in marrow = no stores.
Early response to treatment of iron deficiency - some well-filled RBCs are present
Why is MCHC not usually reported?
High level of error in calculated data.
Discuss the features of normocytic normochromic anaemia.
Largest group of anaemias - common
Causes:
- Haemodilution occurring after acute blood loss
- Chronic or persistent inflammation or infection (mechanism - reduced normal red cell production)
- Renal failure
- Usually a secondary feature of an underlying disorder
Name the features of macrocytic anaemia.
Common in liver disease
Megaloblastic anaemia is an important cause:
- caused by deficiency of vitamins needed for nucleic acid metabolism (folic acid/vit B12)
Delayed and abnormal maturation in marrow:
- many dividing cells die due to DNA errors caused by lack of nucleotides
- affects all tissues but blood abnormalities are usual means for diagnosis
What is haemopoiesis?
Production of blood cells
Where does haemopoiesis occur in fetuses?
Liver and spleen in vascular sinuses
Bone marrow - as bones develop
Where does haemopoiesis occur in children?
Bone marrow - progressive loss from limb bones
Where does haemopoiesis occur in adults?
Bone marrow - axial skeleton mainly (skull, vertebrae, ribs, sternum, coccyx)
Name and describe the different types of stem cells.
Totipotent stem cells - embryonic development, can form any tissue
Pluripotent stem cells - increasing specialization to produce a limited range cell types
Adult stem cells (progenitor cells) - present in marrow, low numbers in blood, may be able to enter other tissues & participate in healing
Committed stem cells - myeloid, lymphoid cell lineages
