Blood Basics

Blood is essential to our daily life. It circulates through our bodies delivering essential substances such as nutrients and oxygen to the body cells. There are four basic components that constitute human blood which includes red cells, white cells, platelets and plasma.

Functions of blood

Blood is responsible for transporting nutrients and oxygen to the body tissues and lungs, preventing excessive loss of blood through blood clots, regulating body temperatures, transporting antibodies and cells that fight infections and also transporting waste products from the body parts to the kidney and liver where the blood is filtered and cleaned. Blood contains a mixture of 55 percent plasma fluid while blood cells comprises of 45 percent. Men averages higher pints of blood which is 12 compared to women at 9 pints. Nearly half the volume of blood comprises of cells while the remainder is the plasma fluid. The plasma fluid transports water and other nutrients to the body tissues.

Blood components and their importance

Most often people undergo blood tests or donate blood to their loved ones or people in need of blood. Specialists in the blood (haematologists) advances more in blood specialisation and can prevent and treat blood diseases. Blood is normally tested and treated before any transfer to another human body. Plasma is the fluid part of the blood which is yellow in colour and constituted by water but also contains proteins, sugars, hormones, and salts. Its main purpose is to carry along blood cells, hormones and proteins useful in maintaining balance in the body fluid.

Red blood cells (erythrocytes)

They have a bright red colour and occupies the better of the blood comprising of 40-45% of the blood volume. They have a biconcave disk shape with a flattened centre. Red blood cells are primarily produced by the kidneys through the control of erythropoietin. They are generated from the bone marrow at a rate of four to five billion per hour, and are transferred into the blood stream after seven days of maturity. Red cells got no nucleus unlike other blood cells and making them easy to change shape thus fitting in small blood vessels. However, lack of nucleus in the red cells reduces its life span as it traverses through small blood vessels, where the cell’s membrane is damaged and its energy supplies depleted. In average, red blood cells can only survive 120 days. Red blood cells contain haemoglobin, a special protein that responsible of transporting oxygen to other body tissues from the lungs and returns carbon dioxide to the lungs for exhaling.

White Blood Cells (leukocytes)

The white cells are responsible for protecting the body from infections. They constitute 1%of the blood volume. The neutrophil is the most common white blood cell and is responsible for ‘immediate response’ and comprises of a percentage between 55 and 70 of the white cells. Neutrophil has a life span of a day. Thus the bone marrow has to produce more neutrophils to maintain body protection against infections constantly.
Lymphocyte is also a main white blood cell normally in two cells, T-lymphocyte responsible for attacking cells and tumours that are found to be infectious and regulating how the immune cells function while B lymphocyte is responsible of making antibodies that fight bacteria and viruses.

Platelets

Platelets are fragments of cells. They help in blood clotting process through gathering at the injured vessel. They attach themselves at themselves at the upper side of the injured vessel forming a platform where blood clotting occurs. As a result, a fibrin clot is formed covering the wound thus preventing the blood from dripping. Fibrin forms a scaffolding to the new tissue promoting quick healing. A higher number of platelets in the blood lead to unwanted blood clotting causing heart attacks and strokes. However, antiplatelet therapies have been produced to prevent such cases.