THE BODY’S NATURAL DEFENCES By Ignacio Diego Martinez-Lopez

What happens inside the body? Most pathogens have to get inside our body to spread infection. Once they are inside, the body provides ideal living conditions - plenty of food, water and warmth. Standing in their way is our body's immune system - the body's co-ordinated response to the invading pathogens. The first line of defence is the body's natural barriers. These include: skin nasal hairs, mucus and cilia tears The skin covers the whole body. It protects the body from physical damage, microbe infection and dehydration. Its dry, dead outer cells are difficult for microbes to penetrate, and the sebaceous glands produce oils which help kill microbes. skin barriers

WHITE BLOOD CELLS

What are they? White blood cells are part of the germ-fighting immune system. They are like little warriors floating around in your blood waiting to attack invaders, like viruses and bacteria. You have several types of white blood cells and each has its own special role in fighting off the different kinds of germs that make people sick. There are different types of white blood cell, including granulocytes, myelocytes and lymphocytes, and they all do different jobs.

SEMMELWEISS

Semmelweis’ life Ignaz Semmelweis was a Hungarian physician whose work demonstrated that hand-washing could drastically reduce the number of women dying after childbirth. This work took place in the 1840s, while he was Director of the maternity clinic at the Vienna General Hospital in Austria. We all now know how important it is to wash our hands. In hospitals, antibiotic-resistant strains of bacteria are wiped out by the simple act of hand-washing. Wards are supplied with antiseptic hand gel which medical staff and visitors use before they see patients who are vulnerable to infection. The routine of ‘scrubbing up’ by surgeons before an operation is, of course, a well-established practice. But this was not always the case. Until the late 1800s surgeons did not scrub up before surgery or even wash their hands between patients, causing infections to be transferred from one patient to another. Doctors and medical students routinely moved from dissecting corpses to examining new mothers without first washing their hands, causing death by puerperal or ‘childbed’ fever as a consequence. As dissection became more important to medical practice in the 1800s, this only increased. Through vigorous statistical analysis, Semmelweis figured out where the problem lay and introduced rigorous hand-washing rules in the maternity ward. Deaths were drastically reduced and Semmelweis became known as the ‘saviour of the mothers’. Sadly, Semmelweiss was committed to an insane asylum when he started to exhibit what was possibly the early onset of Alzheimer’s disease. While there he was beaten by the staff and died from his injuries.

Questions 1. Why do we need white blood cells? 2. Why was Semmelweis famous? 3. How does the body protect us? 4. What are the main protectors in our body? 5. From what do white blood cells protect us?

Answers 1. To protect us from viruses and bacteria 2. He demonstrated that by washing your hands the child birth death goes down 3. by killing pathogens that goes inside us 4. Skin, nasal hairs, mucus, cilia and tears 5. viruses and bacteria

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