BLOOD

BY ALEXANDRA BROWN

Blood consists of two main components.1. Plasma, a clear extracellular fluid

2. Formed elements which are erythrocytes, leukocytes and platelets.

THE COMPOSITION OF BLOOD

• Proteins• Enzymes• Nutrients• Wastes• Hormones• Oxygen• Carbon Dioxide• Electrolytes• Salts• lipids

BLOOD PLASMA CONSISTS OF

The main Blood products donated are :• Red Blood cells• Platelets• White Blood Cells• Plasma• Cryoprecipitate• Factor VIII And Monofix

DONATED BLOOD

Blood fractionation is the process of fractionating whole blood, or separating it into its component parts. This is typically done by centrifuging the blood.

A centrifuge is an apparatus that rotates containers at high speeds, creating centrifugal forces. This separates the blood into its different components since blood is a mixture made up of different densities

HOW BLOOD PARTS ARE SEPARATED

• Red Cell Concentrate: Contains about twice as many red blood cells as normal. It is used to boost the oxygen-carrying capacity of patients with anemia or after serious blood loss.

• Platelet Concentrate: Given to patients who need extra blood-clotting capability, such as leukemia sufferers or after severe blood loss.

• White Cell Concentrate: given to patients needing a boost to their immune system, perhaps after severe infection.

• Plasma: Given in emergency to boost the volume of blood after severe blood loss.

THE USES OF EXTRACTED PARTS OF

BLOOD

• Cryoprecipitate: A fraction collected from plasma containing blood-clotting factors given to people suffering severe bleeding.

• Factor VIII and Monofix: Extracts from plasma used to treat people with haemophilia, an incurable disorder where the blood will not clot properly.

THE USES OF EXTRACTED PARTS OF

BLOOD (CONT.)

One of the areas of current research is Haemoglobin-Based Oxygen Carriers

• Haemoglobin extracted from animal blood can be purified and treated so that it is disease-free and cannot cause any allergic or rejection responses in patients.

• The products can be stored for years at room temperature, and promise to be highly effective at carrying oxygen and releasing it into the tissues.

• Haemoglobin-Based oxygen carriers are currently undergoing clinical trials, but have not yet been approved for medical use. Recent trials failed.

ARTIFICIAL BLOOD

Another area of research is Perfluorocarbon-Based Substitutes.

• An area of research that aims to develop a truly artificial blood substitute.

• Perfluorocarbon compunds are the most promising base chemicals. They can carry upto 5 times more oxygen than blood can and can be stored at room temperature indefinatly.

• Perfluorocarbon-based substitutes are made totally sterile and disease free.

ARTIFICIAL BLOOD

Fresh blood cannot be stored for very long, and many parts of the world lack the money to afford necessary storage facilities. Artificial blood can be stored for longer periods of time e.g 2-3 years compared to 3 weeks for human blood, and does not need to be refrigerated.Currently we have to rely on people to donate blood so that all the different components can be extracted, and there are often times when donated blood is in short supply, such as in war time or natural disaster. If artificial blood were available, there would be no problem in supply when the need arose.

THE NEED FOR ARTIFICIAL BLOOD

Artificial blood is needed because many blood products can set off immune-responses in long term patients, even after correct blood-typing. This is similar to rejection of a transplanted organ.Donated blood can carry many diseases such as hepatitis or HIV therefore many screening procedures need to have taken place before giving it to a patient.

THE NEED FOR ARTIFICIAL BLOOD (CONT.)

• Keep it simple science, HSC Biology Topic 1 “Maintaining a Balance”, www.keepitsimplescience.com.au

• Surfing, Biology, Year 12, “Maintaining a Balance” • Blood Function and Composition,

http://www.virtualmedicalcentre.com/anatomy/blood-function-and-composition/30#C3, (14/11/2012)

• TalkTalk, Centrifuge, http://www.talktalk.co.uk/reference/encyclopaedia/hutchinson/m0009940.html,(18/11/2012)

• Wikipedia, Blood Fractionation, http://en.wikipedia.org/wiki/Blood_fractionation,(18/11/2012)

BIBLIOGRAPHY