Blood is a specialized fluid in the body which constitutes 7-8% of the body weight. The blood is composed of plasma (55%), red blood cells (45%), white blood cells and platelets (less than 1%). Functions of our blood include transporting oxygen and nutrients to the tissues, regulating body temperature, carrying cells and antibodies that fight infection, bringing waste products to the kidneys and liver, which filter and clean the blood and preventing excess blood loss by forming blood clot.
Plasma is the liquid component of blood. It contains mixture of salts, hormones and proteins. It helps to maintain blood pressure and regulates body temperature, as well as transporting various essential substances in the body.
Red blood cells
Red blood cells give blood its colour and has a limited lifespan of 120 days. They are produced regularly in our bone marrow. To produce these cells, our body needs iron, protein and vitamins from the food we eat. These cells contain haemoglobin, which main function is to transfer oxygen from the lungs to the rest of the body tissues and return carbon dioxide from the body to the lungs. When there is insufficient level of haemoglobin in the blood system, the amount of oxygen that gets transported throughout the body is reduced, affecting the function of body organs and tissues. If this condition happens, you will most likely feel tired, dizzy, sleepy, lethargic, lack of concentration and look pale.
The most significant impact of low blood cell level in the body is fatigue. It affects our daily lifestyle as we lack the energy and concentration to complete our tasks for the day. Low red blood cell count in women can be due to their heavy menstruation where loss of blood can be massive. This is why some women feel tired, depressed or loss of appetite during this period.
White blood cells
White blood cells originate in the bone marrow and circulates throughout the blood stream. They play an important role in the immune system. They help to fight against infections by attacking bacteria, viruses, and germs that invade the body.
Platelets are the tiny blood cells that help in stopping bleeding by clot formation. Risk for bleeding develops if a platelet count falls drastically. They have an average life span of 8 – 10 days. They look like small plates in their non-active form and grow tentacles and look like spider when they are activated.
- Blood Basics. American Society of Hematology. http://www.hematology.org/Patients/Basics/.
- Vitamin and Mineral Nutrition Information System. WHO. http://www.who.int/vmnis/indicators/haemoglobin.pdf.