Wondrously Woven

The pituitary gland is separated into two sections – the anterior pituitary and the posterior pituitary. The gland is located at the base of the brain and secretes many different hormones. One – from the posterior gland – is called Vasopressin. It is also called anti-diuretic Hormone (ADH). When specialized cells in the body sense an increase in the blood ratio of particles such as sodium, urea, and glucose to the water content, the posterior pituitary gland secretes ADH to normalize that ratio. Too many particles cause water within the cells all over the body to dehydrate. Too few particles, and cells in the body will swell and burst. Depending on circumstances such as the ambient humidity and temperature, exercise, and diet, when ADH works properly, the kidneys of the healthy adult excrete approximately one to two quarts of water each day through urination. When ADH does not work properly – things go terribly wrong. Diabetes Insipidus (not to...

(As always in these posts, my presentation of the facts about our body’s physiology is purposely brief. I do hope, however, that my posts will stir the reader to independent research. In the case of insulin, an internet search for the keyword ‘insulin’ will pull up pages and pages of medical information). -------- Insulin is a hormone produced and released by specialized cells in the pancreas, called ‘beta’ cells. Insulin ‘unlocks’ each of the cells in our body to permit glucose (a form of sugar) to enter and provide the energy cells need to do whatever the cell’s DNA has programmed it to do. Type 1 Diabetes Mellitus is a condition in which the person’s pancreas no longer produces ANY insulin. Unless the person receives insulin from an outside source – such as injections – that person will die. So, here is the point: What a lucky break that over the eons it took for him to evolve, he finally did so at the exact same time as his pancreas beta cells. It had to happen that way. ...

Our blood nourishes and oxygenates every cell in our body. But that blood could not reach those cells without a pressure behind it, forcing it through our body. Just as important, if that pressure decreases too much and for too long – minutes in some cases for the brain and heart – death will occur. So, it just so happens, through a series of physiological events far too complicated for our purposes here, the body maintains blood pressure within a relatively narrow range. One of the ways it does this is through a hormone (renin) produced by the kidneys. For the sake of simplicity, when the kidneys sense a decrease in circulating blood volume (a low circulating blood volume translates into low blood pressure), they secrete renin. Renin travels through the blood system to the liver where it is converted to a substance called angiotensin 1. Angiotensin 1 then travels to the lungs where it is converted into angiotensin 2 (A2). Here is where it gets down to the business of increa...

If you could stretch out the blood vessels in the average adult, it would circle the earth nearly three times. What an astonishing bit of evolutionary accident for all those vessels to derive from a single fertilized ova. Or, it all was planned and initiated by the Creator. Human Circulation

The heart is divided into four chambers. The upper two are called the left and right atria. The bottom two are the left and right ventricles. In the normal heart blood is pushed (pumped) from the atria into each respective ventricle. The ventricles then contract to eject blood into the circulation. The heart muscle itself is unique of all the muscles in the human body. Only in the heart can cells initiate their own electrical discharge. It’s a process called ‘automaticity.’ As the electrically charged ions (potassium, sodium, chloride, and calcium) move into and out of each cell, they initiate an electrical impulse. Unless those electrical discharges could be better utilized, nothing more than a ‘twitching’ would occur in the tissue around each cell. Life, however, could not exist if nothing but a ‘twitching’ occurred in the heart. What the body needs is a coordinated ‘contraction’ of an entire set of cardiac muscle to pump blood from the heart into the body’s circulatio...

Carbon dioxide is the natural byproduct of cellular metabolism. As most people know, we inhale oxygen from the air around us and exhale carbon dioxide (CO2). Everyone knows why we need to inhale oxygen, but not many know why it is important to life that we exhale CO2. That’s the focus of today’s post. CO2, when combined with the water in our blood, becomes carbonic acid. As carbonic acid builds up in our blood system, the acidity of our blood increases. But there is a limit as to how much acidity our body can tolerate. A significant increase for too long – an hour or less in many cases – will kill us. One the other hand, too little acidity in our blood for too long will also kill us. Now here is where we are either the product of an extraordinary chain of lucky evolutionary events – or we are the product of an extraordinary intelligent Creator. Near the part of our brainstem called the ‘medulla’ are specialized cells called chemoreceptors. Those cells respond to changes in ...

Your stomach acid has a pH of around 2.0. That’s the same pH as hydrochloric acid (HCL). Put a few drops of HCL on your kitchen table and it won’t be long before you have a hole in the table. The reason our stomachs need that low a pH is beyond the scope of this simple post, but I hope you will wonder WHY that extremely corrosive acidic environment in our stomach doesn’t dissolve our stomach. One reason has to do with the mucous cells lining our stomach wall. They serve as a protective coating to prevent that from occurring. So, think about this: It is either an astounding bit of luck in the course of our evolutionary development that the mucous cells exist in our stomach . . . . Or those cells were specifically designed by our Creator to protect the stomach from being dissolved by the acid.