Let’s talk about the kidneys
By Penelope A. Domogo, MD
From the top of our head to the tip of our toes, every part of our body has a function. Yup, your hair and your toenails have functions. So are all other parts of your body in between. And because our body is a whole, all parts are interconnected to each other. If you ever experienced a toothache or a headache, you’ll understand what I mean by this interconnectedness.
Our body parts usually work in teams which we call systems. Example, my brain does not work alone as I type this column. Even if I think of words and sentences, you will not be able to know these if I don’t say them or write them, di ba? They remain thoughts. My brain needs pathways where these thoughts will pass to my mouth or fingers. So there is what science calls the “nervous system”. But that will be a topic for the future. Our topic for this week is the urinary system. Why? Because June is National Kidney Month.
The urinary system is composed of 2 kidneys, 2 ureters, I urinary bladder and 1 urethra. This system works in harmony with the other systems in our body to maintain a healthy internal environment for our cells and tissues to function well.
We learn in biology that blood from the heart and running through our arteries contains oxygen and life-giving nutrients and after it has delivered these goods to the cells, it carries back, through the veins, waste materials that the body produces like carbon dioxide and urea. Carbon dioxide is unloaded by the lungs to the outside world and urea, uric acid, and other soluble waste products are unloaded or excreted by the kidneys.
The kidneys filter the blood and as a result produces urine. Urine then flows through the ureters, collected in the bladder and excreted through the urethra. We need at least one properly functioning kidney to survive so we thank God he gave us a spare.
Let us examine the kidney parts and function in detail. Each kidney is only about the size of your fist but it contains a very interesting mix of cells and tissues some of which are round cells, oblong cells, square cells, columns, calyces, and about one million convoluted tube systems called nephrons beautifully curled inside the kidneys. Can you imagine these? Side by side these nephrons are teeny weeny blood vessels. Just imagine how tiny these are – you’ll need a good microscope to see them.
These nephrons act as filters- fine mesh to filter your blood . The “holes” in these filters are so small that only water and small particles are able to get through and bigger particles (but still microscopic) like red blood cells and white blood cells stay in the bloodstream.
As blood passes through the kidney, waste matter like urea, uric acid and those not needed in the body like excess vitamins and minerals, other toxins and excess water are excreted out. Important substances like glucose are retained and needed water is reabsorbed. (Urea and uric acid are produced when foods containing protein like meat, eggs, milk, cheese are metabloized in the body.)
Because of this intricate and complicated cleansing function, the kidneys are able to regulate the concentration of various components of the blood so that a normal pH is maintained. pH is the state of acidity or alkalinity of the blood. Good blood is slightly alkaline.
The kidneys also regulate how much urine is excreted – on a hot sweaty day, you will notice that less urine is produced so it’s more yellow because the waste matter is concentrated. More (and thus less yellow) urine is produced if you drink so much and on cold days. These are common sense.
Blood passes through the kidneys every five minutes – ensuring that waste materials don’t build up. This translates to about 180 liters of blood being processed daily by your amazing kidneys.
One other important function of the kidneys is to produce hormones needed to produce red blood cells and help in bone formation, among other things. Thus patients whose kidneys have failed and are undergoing dialysis need blood transfusion now and then. At present, they are the biggest recipients of donated blood.
All these complicated processes are done by our kidneys without any effort from us! Or has anybody ever commanded her or his kidneys to function or else!? Nobody. Amazing wonderful creation!
As mentioned earlier, our kidneys filter blood. If your blood is too thick and heavy because of the excess sugar, salt and protein and fat you are eating and drinking, after sometime the “holes” will enlarge. Just like what happens to any filter or strainer. Cooks will readily understand what this means. These microscopic filters can also be damaged by toxins like some chemicals in processed food, some medicines or too much of some medicines (that is why we always warn that there is no absolutely safe medicine.) Naturally, when these holes enlarge or destroyed, then bigger particles like red blood cells and white blood cells (also called pus cells) will pass through. So when you have your urine checked, the laboratory will see a lot of particles which should not be in your urine. These are warnings from your body- if you don’t heed them, these will result to more problems later, one of which is kidney failure.
Again, June is National Kidney Month. Time for us to be reminded that we need to pay attention to our amazing, hard-working kidneys. Believe me, you and I will be much happier with all of us having healthy kidneys.**
“Fools think they need no advice, but the wise listen to others.” – Proverbs 12:15