I love travelling; I enjoy driving and I currently work in the private care hire industry, after a period of working for a year as a milkman. Transport is a major service and infrastructural requirement for the socio-economic development of a community. In the United Kingdom, villages, towns, cities, regions, countryside, coastal and urban areas are connected through a network of roads. To be able to drive on these roads, you need to read a copy of The Highway Code, which forms part of the theoretical test to pass in order to be certified by Driver and Vehicle Standards Agency (DVSA) to drive and licensed by the Driver & Vehicle Licensing Authority (DVLA). In the Highway Code, you are introduced to the different types of roads and the standards (speed limits, signs, markings, symbols etc) required to be able to drive safely on them. So, there are built-up areas roads, countryside roads, single carriageways, dual carriageways, and motorways. As a driver, with a full license from the DVLA, I can drive on UK public roads within the restrictions of the type of vehicles I am permitted to drive.

In the UK, the road network provides the infrastructure for vehicles, as a mode of transport, to move people and goods, from point A to point B. In the human body, the arteries and veins provides the infrastructure for the blood, as a mode of transport, to move nutrients, oxygen, carbon dioxide, other biochemical waste and antibodies from point A to point B (cells, tissues and organs); together, they form the circulatory (cardiovascular) system.

How does the blood function as a mode of transport?

Unlike the road network that enables a linear journey from point A to point B, the blood facilitates a circular journey, moving around the cells, tissues, organs of the body to ensure optimal supply of nutrients, oxygen, antibodies and removal of carbon dioxide and other biochemical waste.

At strategic point on most motorways in the UK are located service centres. When going on a long journey, travellers are able to stop at this service centres to get food and refreshments, use the toilet facilities, rest and stretch to maintain alertness, get fuel and any other essentials for their vehicles. In the circulatory system, there are no designated service centres for the blood to visit and perform these functions. To provide similar functions, the blood visits specific organs of the body during its circular flow through the cardiovascular system.

• Arteries: carry blood away from the heart, to deliver nutrients and oxygen to the organs and tissues
• Veins: carry blood back to the heart, removes carbon dioxide (through the pulmonary circulation) and waste products from body tissues by bringing them to appropriate organs to be removed from body
• Capillaries: moves substances into and out of the blood

Service Centres in the body

The Lung: On its journey through the lungs, (through the pulmonary circulation) the blood receives oxygen and releases carbon dioxide. Oxygen is essential for biochemical reactions in the body and carbon dioxide, which is a waste by-product from these biochemical reactions, is toxic when in large amount within the cells of the body.

The red blood cells, a component of the blood, play a critical role in the movement of oxygen in the blood. It contains a protein –haemoglobin – that is able to bind with oxygen molecules and deliver them to cells, tissues and organs for essential biochemical functions.

Image Courtesy Quora.com

Red blood cell count is a simple blood test that measures the amount of red blood cells in your body and invariably the level of haemoglobin in your blood. This can be likened to checking the engine oil level in a vehicle. This count will determine the amount of oxygen that is transported in your body. A red blood cell count is should as an indicator to diagnose iron deficiency anaemia (low red blood cells than normal).

A normal RBC count would be:

• men – 4.7 to 6.1 million cells per microlitre (cells/mcL)
• women – 4.2 to 5.4 million cells/mcL

The Heart: The passage of the blood through the heart is critical. This forms the systemic circulation within the cardiovascular system. The heart is the pumping station that maintains the flow of blood through the body, ensuring it reaches other critical organs of the body including the brain.

The blood pressure is a measurement of the flow of blood through the arteries, an indirect measurement of the pumping function of the heart. The blood pressure is measured within a range (normal blood pressure is considered to be between 90/60mmHg and 120/80mmHg) and is influenced by age, diet, occupation, gender, activities, and environment. This is like speed limits that are stipulated on roads. However, where speed limits are set standards not to be exceeded by drivers, a blood pressure outside the range, either low or high means serious health implications for the individual. Hypertension (high blood pressure) exerts strain on your arteries and can increase risk of heart attack and strokes. Hypotension (low blood pressure) can cause dizziness and fainting.

If you have ever been in a traffic tailback on a motorway, you will acknowledge that it is not a pleasant experience. The blockage of the arteries – atherosclerosis – can lead to a blood flow tailback with serious consequences increasing the risk of a stroke and heart attack. Although several factors can contribute to these diseases, unhealthy eating habits (a diet high in saturated fatty acids and cholesterol), lack of physical exercises and smoking are factors that can be controlled.

The Small Intestine, Liver & Kidneys: On its journey through these organs, the blood achieves several functions.

1. Assimilation of food nutrients that have undergone the digestive process takes place at the small intestine.
2. Conversion and storage of excess food nutrients takes place at the liver.
3. The elimination of biochemical waste takes place at the kidneys.

The ability of the body to regulate blood sugar levels is critical in maintaining an optimal balance of energy supply to the cells, tissues, and organs. Insulin, a hormone in the body aids this process. Low and high blood sugar levels can have serious health implications increasing the risk of diabetes.

When next you are on the road, give a thought to the role of transportation the blood plays in your body and your diet too.