Blood is crucial for transportation of nutrients and gases from an external environment to cells, plus, transporting wastes from cells to be excreted from the body By Kirsten Cluett

Composition of Blood If a mammal’s blood was sampled and spun in a centrifuge… The blood would split into cellular matter and plasma Plasma making up 55% by volume Cell fraction making up 45% - Consisting of red and white blood cells and platelets

Components - Plasma Sticky, off-white slightly salty liquid (Suspends) Red and White Blood cells and platelets Transports nutrients, and other substances e.g. Carbon Dioxide waste Contain substances that stabilise pH and osmotic pressure Substances in plasma clot blood when needed act in immune response

Components – Cellular Matter RED BLOOD CELL: (erythrocytes) Biconcave, disc-shaped In humans have no nuclei Remain in the blood for 3 months Contain haemoglobin (oxy-haemoglobin transporting oxygen) and other respiratory gases are transported 1mL = 5-6 million in blood WHITE BLOOD CELL: (leucocytes) Contain a nucleus Larger than red blood cells Phagocytes – collects at areas of infection, ingesting foreign bodies. Lymphocytes – act against foreign material, and make antibodies to fight against disease Important in immune response 1mL = 4000-12000 in blood PLATELETS: Makes up a tiny <0.01% part in one blood part Helps the blood to clot Aids in inflammation

Blood Composition - Centrifuged

Donated Blood Usually 450 mL given each donation Donors are screened and regulated Checked to prevent antibodies in donation do not react with patient’s red cell antigens Packaged into products: Whole blood Packaged red blood cells Plasma Platelet concentrate Cryopreciptated AHF Plasma fractions

Donated Blood Extracted Parts Various components of blood can be separated from whole blood to help a patient’s specific needs Red Blood Cells: Increase oxygen carried to body’s tissues. Given to people with… anaemia, blood loss patients and patients with bone marrow red blood cell deficiency Platelets: Are essential for blood clotting For cancer of the blood, Leukaemia (Cancer patients often don’t make enough blood platelets) Plasma: Blood-clotting factors, adjusts osmotic pressure of blood For people with clotting disorders like Haemophilia. Adjusts osmotic pressure of blood Immunoglobins: Antibodies. Infection-fighting part of blood plasma For people with difficulty fighting infections and immune system malfunction e.g. AIDS. Clotting factors 8 and 11 Granulocytes

How are These Parts Separated? Packaged red blood cells: Extracted from whole blood by removing liquid plasma. The blood is centrifuged and red blood cells will fall the bottom, the heaviest particle Suitable for sufferers of kidney failure and chronic anaemia Cryoprecipitated AHF: To be removed from plasma, it is frozen then thawed Controls or prevents bleeding – suitable for people with haemophilia

Continued. Blood processing allows blood parts to be separated from each other. There are different methods to achieve this A hematocrit tube holds blood and is placed in a centrifuge - causing components to split and red blood cells falling to the bottom of the tube Blood component therapy allows an extracted component of the blood (e.g. plasma) to be given to a patient by method of blood transfusion (here the same blood type must be donated) Blood component therapy allows specific blood components to be brought together for a patient’s needs

Uses of Extracted Parts of Blood Red blood cells Majority to people with cancer Traumatic accidents (with dramatic blood loss) Burns victims or surgery patients Plasma Trauma, burns and blood disease Makes up 17 life-saving products Platelets People with low platelet count Bleeding or risk of bleeding patients with non-functioning platelets Cancer patients (chemotherapy) Bone marrow transplant Liver disease Major trauma Surgery patients

Red Cross Blood Service

Used when a patient suffers large volumes of blood loss Carry oxygen and carbon dioxide Do not clot blood or involved in immune defence Substitute for plasma to maintain blood pressure (but do not supply oxygen to tissues) Two types of oxygen carriers: haemoglobin-based and Perfluerochemicals Artificial blood fluids: Normal saline (same concentration as blood 0.9%) Dextrose 4% in a 0.18% saline solution Artificial Blood

Need for Artificial Blood Advantageous: Free of infectious agents, non-toxic and disease free which is important in countries where blood transfusions contain diseases e.g. Nigeria has AIDS spreading in blood transfusions Universal acceptance Stored at room temperature Available in large supplies PFC-based artificial blood can be used temporarily during open heart surgery – minimises blood loss during operation Transfusion without any tests required (blood type does not need to be matched and antigens will not interfere) Can be kept for long periods of time (2-3 years) compared to human blood’s 3 weeks Rapid treatment in trauma patients Oxygen carrying blood substitutes can be used for religious/cultural objectors of blood transfusions Currently cost-effective Useful in surgery, trauma and oxygenation of tumours during chemotherapy

Bibliography Hill, J. and Alford, D. (2004). Excel HSC Biology. New South Wales: Pascal Press Humphreys, K. (2004). Surfing. New South Wales: Science Press Mudie, K. and brotherton, J. (2004). Heinemann Biology. Victoria: Reed International Books Australia Pty Ltd ‘How donated blood is used’ http://www.donateblood.com.au/why-donate/blood-use (24 Nov 2012)