Flow of life

Flow of Life

How much do you know about the life-giving red fluid that flows through your body?

Every living being requires blood to survive. Humans have about five to six litres of blood flowing through our veins and arteries. Your heart is responsible for pumping this blood, ensuring that it is circulated around your body. You can feel your heart doing its job when you place your fingers at your neck or wrist. You’ll feel a distinct throbbing, which is known as the pulse.

Blood plays a significant role in your body. It has a variety of functions including transporting oxygen from your lungs to the organs, regulating your body temperature and destroying dangerous bacteria or foreign elements present in your body.

What’s in it?

Your blood consists of several components — red blood cells, white blood cells, platelets and liquid known as plasma.


Plasma is a pale yellow liquid which makes up about 50 percent of your blood. It is the liquid portion of your blood which transports your blood cells around your body. Plasma plays an important role in maintaining your blood pressure and regulating your body temperature. Aside from blood cells, it also contains essential substances such as minerals, hormones, albumin (a protein secreted by the liver and which plays an important role in regulating blood volume), coagulation factors (blood clotting) and immunoglobins (antibodies for your body’s immune system).

Plasma can be obtained from blood which has been donated. It will be separated and frozen until needed. Plasma can be used in several ways including via transfusion for a person who has lost large amounts of blood due to an accident or even for patients suffering from blood disorders such as hemophilia.

Red blood cells

Your red blood cells’ vital role is to transport oxygen around your body and carbon dioxide out of your body. Red blood cells contain hemoglobin which allows this process to occur. It is also responsible for the colour of your blood. Healthy red blood cells are round in shape, like a disc or doughnut without a hole in the centre.

There are some types of vitamins and minerals that can help you maintain healthy red blood cells in your body. These include vitamin E, B2, B3, B12 and iron. People with unhealthy red blood cells or who suffer from a deficiency of red blood cells may feel light headed and tired all the time. Generally, red blood cells live for about 120 days. Your bone marrow is responsible for producing red blood cells, ensuring that there is a healthy count in your body, at all times.

White blood cells

Also known as leukocytes, the main role of white blood cells is to protect your body from harmful pathogens and bacteria. There are several types of white blood cells. Some of the common types are lymphocytes and neutrophils. Lymphocytes are produced in lymphoid tissue present in your lymph nodes and spleen. This type of white blood cell is responsible for identifying foreign substances in your blood.

Neutrophils on the other hand are important in your body’s defense against bacterial infections. They are made in your bone marrow and circulate through your bloodstream. When there is a bacterial infection in your body, higher amounts of neutrophils will be produced to fight it.  White blood cells tend to have a shorter lifespan compared to red blood cells. They generally last for just one to three days and because of this, they need to be produced, constantly.


Platelets (also known as thrombocytes) identify any damaged blood vessels in your body and bind the site of the damaged vessel. Under a microscope, inactive platelets look like dinner plates. However, when they become active, sticky tentacles will form and this will help them stick together and bind the damaged vessel.  Just like your red and white blood cells, platelets are also made in your bone marrow. They live for about eight to ten days in your bloodstream.

4 different types

Although all types of blood may look the same and have the same components, they are not alike. According to the American Red Cross, there are eight different blood types and they are determined by the presence or absence of certain antigens. These antigens can trigger an immune response if found to be foreign to your body. This is why your blood type is carefully matched during a blood transfusion.

Generally, blood is classified into four different groups. They are A, B, AB and O, with each blood type classified further into negative and positive.

Blood type A – People with blood type A have only the A antigen in their red blood cells and B antibody in their plasma. People with this blood type can receive from donors with blood type A and O.

Blood type B – People with blood type B have only the  B antigen in their red blood cells and A antibody in their plasma. People with blood type B can receive from donors B and O.

Blood type AB – People with blood type AB have both A and B antigens in their red blood cells but no A or B antibody in their plasma. People with blood type AB can receive from all four blood types but can only donate to other AB blood types.

Blood type O – People with blood type O have neither A or B antigens found in their red blood cells but have both A and B antibodies in their plasma. Blood type O (known as the universal donor) can donate to all four blood types but can only receive blood from other O blood types.

Rh factor is the type of protein in your blood that can either be present or absent. Positive (+) indicates the former and negative (-), the latter. Rh negative blood will be given to patients with Rh negative. The same applies for patients who are Rh positive whereby, only Rh positive blood with be given to patients with the same Rh factor.

Knowing about your blood — its components and functions — as well as your blood type will be helpful in case of emergencies. This is especially important if you need a blood transfusion or if you are planning to donate blood. Your blood type is part of your identity as well. Through it, you are able to know about your state of health and genetically inherited conditions. Hence, it is vital that you know all about it.

*A simple blood test conducted by a doctor will determine your blood type as well as the shape and size of your blood cells. If you don’t know your blood type, be sure to get yourself tested.

Are you a blood donor yet? 

blood donation

Donating your blood can save a life and there are health benefits too — including reducing your risk of cardiovascular disease. Studies published in the American Journal of Epidemiology found that blood donors are 88 percent less likely to suffer a heart attack and 33 percent less likely to suffer from any type of cardiovascular disease.

It doesn’t matter about blood group you belong to. Every pint of blood donated, is a gift of life to someone today. Interested in being a blood donor? Log on to the National Blood Centre’s website (pdn.gov.my).

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