Blood Cells: RBC WBC platelets

Cells and plasma

40-50% 35-45%

Bone marrow

7

Lacks nucleus, mitochondria, golgi, ribsomes. Packed with haemoglobin. Contains enzymes needed for anaerobic metabolism of glucose.

The normoblast

8-10 micrometres highly condensed nucleus contains most of the haemoglobin still has a few mitochondria and ribosomes

Nucleus ejected and remainder of cell enters the blood as a reticulocyte. It takes 1-2 days for remaining RNA and organelles to be lost. Reticulocyte count is 1% of total rbc.

Function = haemostasis (blood clotting) and maintenance of blood vessels. 2-3 micrometres in diameter with a bi - convex shape, no nucleus. They are produced in the bone marrow.

They adhere to fibrin filaments and damaged endothelial cells forming a blood clot.

A giant cell with a large irregular nucleus. All the nuclear content is needed to support all the cytoplasm in the cell. Necessary for blood clotting.

• Granulocytes (neutrophils, basophil, eosinophil) 2. Mononuclear leukocytes (monocytes, lymphocytes)

• myeloid (bone-marrow derived) - lymphoid (originate in bone marrow, mature in tissues such as thymus)

Neutrophils >90% 12-14um Highly lobulated nucleus with 2-5 lobes Abundant glycogen Highly phagocyte and motile 5-90 hours in circulation Attracted to sites of inflammation On activation, adhere to receptors on endothelial cells expressed in response to secretion of cytokines

They die due to limited synthetic capabilities.

They rely on glycolysis meaning they have no form of new energy so the neutrophils die after a sudden release of energy.

12-17 micrometres diameter bi-lobed nucleus has specific granules large ovular shape major role in destruction of parasites role in the initiation and maintenance of inflammatory responses leave circulation within 8-12 hours of release from bone marrow

14-16 micrometre diameter bi-lobed nucleus granules containing histamine release cytokines when stimulated closely related to tissue mast cells but from a different precursor

largest blood cell (up to 20 micrometres diameter) Nucleus which is kidney bean shaped Highly phagocytic and motile Leave blood within 2 days of release Enter tissues to become macrophages lifespan of months/years

• Defence against micro-organisms • Refuse - collection for removal of tissue debris, old red blood cells • Antigen presentation - displayed on surface and presented to T lymphocytes to tigger an immune response • Cytokine secretion

6-9 micrometres condensed nucleus occupies 90% of cell thin rim of cytoplasm responsible for adaptive immunity B - surface immunoglobulin for antigen receptor, respond to antigen by proliferating and maturing into plasma cells which then secrete the same immunoglobin T - receptor for antigen, they secrete cytokines into blood stream

The process by which mature blood cells are generated from precursor cells. 2-2.5 weeks = earliest red cells are nucleated, 5 weeks = haemopoieses shift to liver 4-5 months = haemopoieses shits to bone marrow

All blood cells arise from a common pluripotent stem cells. This gives rise to unipotent stem cells. Erythropoietin is what causes the production of erythrocytes.

• fluid component of blood • aqueous solution of salts, nutrients and plasma proteins Plasma proteins exert a colloid osmotic pressure to help regulate aqueous exchange between plasma and extracellular fluid. Albumins - involved in transport of hormones, vitamins and enzymes Globulins - include immunoglobulins Fibrinogen - precursor or fibrin, important in blood clotting