Blood Flashcards
What order are things in is you collect a blood sample in a tube with anticoagulant and spin it down
Erythrocytes at the bottom
Thin buffy coat layer containing leukocytes
Above the cells you get the liquid phase (plasma)
PCV/haematocrit
% value of height of cell material relative to total blood height in capillary tube (freq used clinical test)
Plasma cont
Plasma proteins (albumin, globulins, fibrinogen) Inorganic salts Organic components (amino acids, vitamins, hormones, lipids)
Serum
Take blood sample and leave to clot with no anticoagulant and centrifuge down then left with clot containing clotting factors and cells at bottom and liquid fraction above called serum
Serum similar to plasma but less protein
Plasma v serum
Plasma all pros present
Serum clotting pros settled out so lower pro level
Both used for a range of biochem blood tests
Blood fxs
Nutrient supply Waste (of metabolism) removal BP maintenance Defensive role Signalling molecule supply Heat distribution and control
How blood maintain BP
Blood pros maintaining on optic pressure or through reg of blood vol
How blood control heat/ distribution
Through preferential vasoconstriction/dilation and counter current mechanisms
Broad blood cell division
Erythrocytes - mainly carry O2 and co2
Leukocytes - defence cells
Thrombocytes - crucial for control of haemorrhage through clot formation
Production of erythrocytes and haemoglobin production
Bone marrow
During diff cells synth large punts of intracellular pro haemoglobin (basic pro with high affinity for O2)
High haemoglobin conc give eosinophilic colour when stained
Erythrocytes fx and how it does this
Transport haemoglobin round the body to max gas exchange
Mature facilitate by only carries what is necessary - extrudes nucleus and allows cytoplasmic organelles to degen
Erythrocytes comp
Outer plasma mem
Haemoglobin
Some enz &I pros necessary for gas exchange and plasma mem maintenance
Avian have nucleus
Erythrocyte resp
No mitochondria so entirely dep on anaerobic glucose met for E
Why do erythrocytes die
Run out of enz and can’t produce more as no organelles
Av lifespan canine erythrocytes
120 days
RBC shape
Highly optimised for fx
Bi concave disc allows for 20-30% once in SA further facilitating gas exchange
Allows central pallor to be observed in blood smears due to its shape
This shape also allows for deformation which aids in movement through small spaces like capillaries
Reticulicytes
Immature erythrocytes released from bone marrow before final stages of diff complete, so it still contains some cell organelles eg mit, ribosomes, Golgi
Duration of final reticulicyte maturation
24-48hr and includes synth of the last remaining 20% haemoglobin
How much of blood does reticulocytes make up and appearance
Less than 1% in blood smears
Can be visualised with basic dye as ribosomal RNA blue
Slightly paper due to lower haemoglobin content
Leukocyte distribution
1:400-1300
Avian 1:100
Classification of WBCs
Granulocytes - all multi-loved nuclei and named for type specific granules:neutrophils, eosinophils, basophils
Mononuclear leukocytes - (monocytes and lymphocytes have nonlobed nuclei)
WBC fx
Major part of defence against foreign invaders
Main fxs in tissues and blood circulation is a means of transport to their site of action where the cells migrate into the tissues.
How WBCs respond when req
When specific WBCs req they once nos and move to their target site resulting in increased in that cell in circulation - this can be observed in blood samples
Components
The formed elements (cells&a platelets)
The plasma
Neutrophils
General
Most numerous (60-70%)
12microm diameter
Highly lobulated nuclei
Neutrophil
Fx
Mainly phagocytosis as part of acute inflammatory response
Particularly activated in response to bacterial infection
How neutrophils phagocytose
Cell attracted out of blood vessel to site of infection by chemical attractants gen by microorgs during diapedesis
Phagocytosis occurs
Primary (lysosomal) secondary (specifc) and tertiary granules attracted from neutrophil cyt to vacuole and mem fuse, contents secrete into vacuile
Enzymes etc in the neutrophil
Lysozyme
Gelatinase
Myeloperoxidase enz
Cationic proteins - defensins
Neutriphil life span
Cant phagocyt anything bigger than bacteria and can ingest 5-25 before it is killed by toxins & enz produced
Half life in the circulation is 6hr so entire neutrophil supply in blood replaced 2x a day
Pus comp
Bacteria
Necrotic tissue
Mass of dying neutrophils
Eosinophils
General, storage
Less numerous (2-10%)
Sleectively stored in bone marrow for several days post production then released into circulation for 3-8 hr befor entering skin, pulmonary of Gi mucosae
12-17microm diameter
Bilobed nucleus
Eosinophil fx
Def against parasites incr no present in allergic cond
Granules cont potent bacteria killing toxins
Cells are phagocytic esp have affinity for antigen antibody complexes
If target too large for engulfation release granules into ext enviro causing injury to certain parasites
Eosinophil comp
Large ovoid eosinophilic granules in cat/dog (more homogenous in cow & horse)
Major basic pro make up 50% of granule and is theoried to play crucial role in cells ability to damage larva tissue stage of helminthic parasites
Basophils
General
Multilobed nucleus can be obscured by many densely basophilic granules
Rare (
Basophil comp
Similarities to mast cell incl granule content (histamine, heparin, tryptase) and activation via IgE antibody binding
Basophil fx
Unknown
Implicated in host defence against parasites and allergic diseases.
Basophilia consistent feature of heart worm (dirofilariasis)
Lymphocyte types
T
B
Natural killer cells
Lymphocytes general
Smallest wbc 6-9microm 12-30% Only just bugger than rbc Large round nucleus Variable scant basophilic cyt amount No visible granules Activated have more cyt & diameter up to 15microm
Lymphocyte fx
Not phagocytic
Adaptive cellular immune response esp key with viral inf
T lymphocytes
Precursors in BM migrate to thymus to mature into either cytotoxic T cells or helper/regulatory cells
Mature cells migrate to secondary lymphoid organs eg spleen lymph nodes between which they constantly circulate via blood looking for antigens
B lymphocytes
Precursors in BM, mature in BM in most mammals with additional sites (bursa of fabricius in birds)
On activation mature B undergo mitosis forming clones that dev into antibody secreting plasma cells or memory cells
NK cells
Large granular lymphocytes that perform non spec killing of tumour and virus inf cells
Monocytes general
Largest wbcs 20microm diameter
3-10%
Horse shoe shaped eccentric nucleus
Basophilic nucleus, golgi rer mitoch
Monocytes life cycle
8hr circulation before migration into tissues to diff into tissue spec macrophages
Monocyte fx
Active show diapedesis, amoeboid activity and chemotaxis in response to foreign material
Highly phagocytic
Destruction of cellular debris arising due to host defence and normal cell turn over also (eg osteoclast)
Monocyte lymphocyte interaction
Monocytes interact and play a key role in recog and interact of immuno competent cells with antigen
Thrombocytes general
2- 5 microm lifespan 8-12 days
Nonnucleated disc shaped
Formed in BM by budding off cyt of large precursor megakaryocyte cells
Well dev cytoskeleton
Rich in actin myosin which cintracts allowing for clot aggregation & contraction
Thrombocytes in haemostasis 1
1 form plugs, occlude sites of vascular damage by attaching to exposed collagen fibres at wound edge
Thrombocytes in haemostasis 2
Promote clot formation
Thrombocytes in haemostasis 3
Secrete factors involved in vascular repair. Important products incl: fibrinogen and other coag cascade pros, serotonin
Where fibrinogen etc found
Aloha granules
Where serotonin produced and found fx
Conc in dense granules
Produced in enterochromaffin cells of gut
Fx vasoconstriction
Haematopoiesis
Production of blood cells from precursor cells aka multipotent HSC
Where does early embryo haematopoiesis occur
Yolk sak before liver & spleen take over hntil last trimester when bones have dev and BM becomes main site
MHSC divide to produce
2 daughter cells 1 MHSC and either 1 common myeloid or 1 common lymphoid prog cell committed to spec lineages
Myeloid prog - erythrocyte
Proerythroblast diff to basophilic EB polychromatic EB orthochromatic EB reticulicyte before finally RBC during erythropoiesis
Myeloid prog - thrombocyte
Megakaryocytes dev and produce thrombocytes in thrombopoiesis
Myeloid prog - mast cell
Dev from distinct myeloid prog cell lineage
Myeloif prog - myeloblast
Give rise to either monocytopoiesis (give rise ti monocytes, eventually mature macrophages & myeloid dendritic cells) Or granulopoiesis (give rise to 3 precursors for 3 granulocytes)
Lymphoid prog - NK cells and small lymphocytes
And other lineage
In Lymphopoiesis lymphoblast give rise to NK and small lymphocytes which mature into B & T lymphs
Other lineage is that lymphoid prog cell give rise to lymphoid dendritic cells
Cause of incr PCV
Dehydration
Cause of decr PCV
Anaemia
