Our natural defences
Posted on 18th November 2020 at 07:14
Although it underpins every blog post we write – and everything we do – it’s been a while since we’ve talked specifically about the miracle that is the human body. Our first – and life long – home. And we bet you’ve never thought about your body in that way before!
Despite all of this, it’s the one thing we take completely for granted. Well, until something goes “wrong” and we can’t do all the things we want to…..
While we may like to think – particularly in this technological age – that scientists understand exactly how the human body works, this is far from the case. Let alone have a solution for every “problem” which may occur.
The aspect we’d like to talk about today is a good example of this. What’s particularly interesting – well, to us at least (!) – is how little coverage and importance it’s being given in mainstream media and health forums. Thankfully, the opposite is the case elsewhere. Particularly as winter approaches, let alone everything else going on at the moment. If you haven’t guessed it already, we’re talking about the Immune System.
Before we go any further, you’ll be pleased to hear that we’re not going to go into too much scientific – or gory – detail. Instead, we’re going to talk generally. Keep it nice and simple. Hurrah! Even better, we’re going to use a popular analogy. Ah, now the picture at the top of the post makes sense!
As you would expect, there are many different definitions for the Immune System, ranging from the very simple to the incredibly complex. However, they can all be summarised as the body’s defence system which protects against disease causing germs – also known as pathogens – AND harmful substances from the environment. Or, put another way, it protects us from anything deemed to be “not me” and so could potentially pose a threat.
While the Immune System is often thought of in terms of White Blood Cells and the immune response, it’s much, much more than that. A complex – and body wide – system, encompassing many different layers of defences and a huge number of different cells, tissues and organs. It’s also worth emphasising that all the participants – if that’s the right word – carry out a wide range of other functions too and are not just a part of the Immune System.
Which brings us on to the popular analogy, hinted at above. The medieval castle with its many different layers of defences before invaders encountered any of the soldiers guarding it. Let alone the elite soldiers. A moat and drawbridge. High walls. Well guarded gates. Progressively stronger physical defences. Better trained and equipped soldiers. And, at the centre, a small inner sanctum guarded by elite soldiers with the best equipment.
If you look at the castle, it’s obvious what the first line of defence is all about. Physical barriers designed to keep invaders out. A moat, drawbridge, thick outer walls and gates. And, so, it is with the body. While we don’t tend to think of the Skin as part of the Immune System, that’s exactly what it is. A tough outer wall to keep everything inside protected from whatever may be outside (!). Intact, it’s extremely difficult for anything to penetrate it.
It even has its own soldiers, with millions – well, more likely billions (!) – of bacteria living on its surface. These so called “good bacteria” can also be found in the Digestive System, which is now being seen as playing an important part in the immune response.
So, what about the gates? Well, that’s the job of Mucous Membranes. They provide a mechanical barrier – a gate – on all body openings. Simple examples are the Mouth, Nose, Ears and Eyes. However, it doesn’t stop there, as these membranes continue deep into the body so providing a continuity of defences. For example, into the Respiratory and Digestive Systems.
As the name suggests, Mucus Membranes also secrete mucus, a slimy substance which traps any external substances or pathogens that do manage to enter the body. There are also Cilia, small hairs, which help sweep the mucus and anything trapped in it, back towards the body openings so it can be expelled from the Body. Perhaps by a cough or sneeze.
The Mucous Membranes are also supported by other chemical and biological barriers. For example, sweat, tears and saliva. Acidic urine to help flush the Urinary System. And, if you’re thinking that the castle analogy doesn’t quite work here, just think about the boiling oil and other equally undesirable things that were thrown down on invaders!
If these are breached, then there are the second lines of defence. And this is where the response starts to become more specific, although there are still standard “catch all” responses alongside.
The standard – non specific – responses include the ones we know well from acute infections. An elevated body temperature or fever to make the body less hospitable to invaders, who operate within a fairly narrow temperature band. Inflammation to provide a physical barrier around the affected area and isolate the invaders from the rest of the body.
Alongside these are specific responses, which is where the White Blood Cells comes in. These are stored, manufactured and released to deal with a specific invader. In other words, the better trained soldiers start to be activated. For example, from the Tonsils in the Throat, Adenoids at the back of the Nose, Gut Associated Lymph Tissue (GALT, not the most memorable name (!)) in the Digestive System.
These are supported and augmented by the third line of defence, the elite troops and Lymphatic System. Huge numbers of White Blood Cells, specific to the particular threat, are and sent to the areas concerned via the blood stream. At the same time, the Lymphatic System helps remove the after effects, using lymph fluid to flush away the debris. This is filtered by the Lymph Nodes before being released into the blood stream for disposal. To the Liver, which acts as the body’s waste disposal, storage and recycling centre. To the Kidneys to release in the urine. And, don’t forget the Skin, which helps to release waste materials via sweat and secretions.
Now, even though we’ve kept it simple, it’s easy to see how sophisticated a full Immune System response can be and how well protected we really are. How it’s designed to gradually ramp up, as the threat – and how far it's penetrated into the body – increase. Why a full immune response requires a huge amount of energy. It’s something we’ve talked about before and can be found here.
This is why it’s important to make sure that the Immune System – and body generally (!) – has all the support and resources it needs. And, we’re sure you know where we’re going with this! But, just in case you don’t, it’s about all the things you do every day AND being sensible if the worst happens. This is why, as so often is the case, your Mother’s / Grandmother’s approach is the one that works best (!). If you need a quick reminder, just click here and here.
And there’s one more thing that we’d like to highlight before we close for today. This is that your Immune System – and body generally – is much more intelligent that we ever give it credit for. Even better, it has an excellent memory. So, while pathogens and external threats are constantly changing – the bugs doing the rounds this year and are ALWAYS a little different to that of previous years – the body still recognises their general form and the family they come from.
Just think how easy it is to recognise family traits, even though you haven’t met that particular individual before. You may not know their name, but you definitely know which family they came from! This means you have a pretty good idea of what they’re going to be like and, just as important, how to deal with them even though it's the first time you’ve encountered them…
And, it’s exactly the same for the body. This is why there’s nothing wrong with having an acute – a Cold or Flu – from time to time. Not only does it give the Immune System a good work out – and detox too (!) – but adds to your body’s database for the future.
As always, the choice is yours.
Picture by unknown author
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