Bone marrow and Leucocytes Flashcards
list the cellular components of blood
erythrocytes (RBC)
platelets (thrombocytes)
leukocytes (WBCs)
- granular leukocytes = neutrophils, eosinophils, basophils
- non granular leucocytes = monocytes, lymphocytes (T-cells, B-cells, NK cells)
what does the term leucoytosis mean?
neutrophilia? lymphocytosis? monocytosis? eosinophilia? basophilia?
leucocytosis = increse in WBC in general
neutrophilia, lymocytosis, monocytosis, eosinophilia, basophilia = increase in that specific WBC
what does the term leucopenia mean?
neutropenia, lymphopenia, monocytopenia, eosinopenia?
leucopenia = decrease in WBC
neutropenia, lymphopenia, monocytopenia, eosinopenia = decrease in that specific WBC type
what colour will a nucleus stain when Romanowsky type stains are used? why?
Blue
because the nucleus is filled with acidic material which stains blue
what are the common romaowsky stains
- diff quic/rapid diff etc.
- leishman (used in blood smears and helps to distinguish certain protozoan parasites)
- wright (used on BM aspirates and blood smears
- Giemsa (stains cytoplasm shades of pink, used on blood smears)
BM = bone marrow
describe the histological characteristics of a neutrophil
- 2 or more lobed nuclei
- often connected by thin strands of chromatin
- sparse granules
- obviously larger than erythrocytes (10-12 micm)
what are the histological features of an eosinophil
- 2 lobed nucleus that take up less than half of the cell
- dense orange granules
- blue cytoplasm
- larger than erythrocyte, about the same size as neutrophil
what are the histological features of a basophil
- nucleus lobed but not so well defined
- dense blue granules within cytoplams
- rare in blood
- larger than erythrocytes, same size as neutrophil
- entire cell may appear purple
describe the histological features of monocytes
- largest of the WBCs in a blood smear (18 micm)
- 2 lobes that take up more than half of the cell
- nucleus typically more indented than lymphocyte
how long do neutrophils circulate in blood/survive in tissue?
- circulate in blood for minutes up to 6-8 hrs
- survive in tissue 1-2 days
what do neutrophils do
- chemotaxis
- phagocytosis & killing
Oxygen independent killing: occurs in sites of poor blood flow or at abscesses (release enzymes to kill bacteria/virus)
oxygen dependent killing: occurs after phagocytosis (often called respiratory burst)
list the stages of development for a neutrophil in BM and what is a left shift?
bone marrow
- myeloblast
- promyelocyte
- myelocyte
- metamyelocyte
- band neutrophil
- segmented neutrophil
a left shift occurs most often during inflammation. it describes an increase in circulatinf neutrophils and we begin to see immature neutrophils or band forms within the blood (left the BM too early) it is called a left shit because we write the developmental stages of neutrophils from left to right in increasing age.
how many eosinophils should we see in healthy blood and when should we expect to see them in unhealthy blood
very few - 1-2 is normal
strongly associated with allergies, parasites and fibrosis
describe some species variations of eosinophils
cats have very small, fine granules
horses have large granules
is it normal to see basophils in the blood and what are they associated with
it is extremely rare to see basophils in the blood
Associated with parasitic infections and allergies (recruited into tissue)
- normal ranges are 0-300 micl in blood
- rabbits > ruminants & horses > cats &dogs
- basopenia is not concerning HOWEVER, basophilia is a sign of pathology/disease
what granules do basophils have
- heparin
- histamine
- leuktrienes
- lysosomes
what is the most important function of basophils
immediate type hypersensitivity - cause of allergy
describe the receptors found on mast cells
- have IgE receptors on their surface that are triggered when antigens bind to them (releases granules)
what are mast cells associated with
- response to allergy
- parasitic infections
describe features of mast cells histologically and where do you expect to find them
- round nuclei
- granular cytoplasm
found in connective tissue NOT blood
what types of cells would you see in a bone marrow aspirate
- RBC precursors
- WBCC precursors
- magakaryocyte
- myeloid:erythroid ratio
orderly progression of cells through precurorsor stages to final mature stages
