Mr. Minderhoud is a teacher in Covenant Christian High School and a member of Hope Protestant Reformed Church, Walker, Michigan.
We believe that the same God, after He had created all things, did not forsake them, or give them up to fortune or chance, but that He rules and governs them according to His holy will, so that nothing happens in this world without His appointment” (Belgic Confession, Art. 13). Everything in the creation ought to draw our attention to the almighty power of the sovereign Creator and His absolute control over all things. Yet, the world attempts to explain all of the wonders observable in the creation in terms of “natural selection” or “probability” and “chance,” and we would do the same if not for the grace of God. Our sinful natures attempt to suppress the truth of a sovereign Creator, and desire to invent an explanation based on our own thinking. But, thanks be to God, by His sovereign and irresistible grace, our blind eyes have been opened and our hard heart softened so that we can look at the creation and begin to see the handiwork of the Creator. Now that we have eyes to see, we see a creation singing the praises of God. Now we see a creation that leads us “to contemplate the invisible things of God” (Belgic Confession, Art. 2). We do well to contemplate the sovereign control of God as we consider in this article one of the means God uses to direct functions within our bodies— a small but glorious reminder of His sovereign governing Hand.
In addition to the nervous system, which controls the activities of the body with the use of electrical signals, the endocrine system also is highly involved in controlling functions and activities of the body. The endocrine system is a system of chemical messengers (hormones), secreted from specific glands, that are distributed throughout the body—the pituitary gland in the brain, the thyroid gland in the neck, the adrenal glands by the kidneys, and the reproductive glands, to name a few. These glands secrete unique chemicals that rush through the bloodstream communicating important messages to various cells of the body. Interestingly, these glands do not distribute their hormones through tubes directly to the targeted cells or organs, but simply distribute the hormones to the cells by way of the bloodstream.
This endocrine system is extremely fascinating for a variety of reasons, not the least of which is the fact that God uses chemicals— tiny groups of atoms (those tiny building blocks of matter that we have examined previously in this rubric)—to communicate necessary messages to various body cells. The chemicals, or hormones, are capable of communicating with specific cells because the target cells were designed to receive and recognize only the particular chemical that will cause the necessary changes in that cell.
A simple analogy may help us understand this. Every conscientious homeowner has locks on the doors of his home. He uses these locks when he leaves the home. Only one set of keys will fit the lock and unlock the door. So it is with the hormones of the endocrine system. One might consider the hormone to be like a key to a lock. The hormone may try to fit into every cell with which it comes in contact, but because of the wisdom of God, the hormone will “unlock” only the particular cell God has designed it to “unlock.” The “unlocked” cell is now able to accomplish the task it is called to do. In the wisdom of God, cells are constantly “unlocked” by specific chemical messengers so that particular bodily functions can be controlled and regulated. What an amazing design God has made, in that cells communicate through the use of tiny groups of atoms! God’s intricate design is further illustrated in that cells will respond only to specifically “shaped” groups of atoms and simply “ignore” the other hormones that pass by! Truly we see the hand of an omnipotent, divine Creator, who created of nothing all things by His Word—not the outcome of some evolutionary process of development. Our God is great and greatly to be praised!
The greatness of our God and His providential government is demonstrated in how He uses the tiny hormone molecules to regulate and control activities of the cells of the body, and thereby literally control the many functions of the body itself. Time and space prevent discussing the multitude of body functions that are intimately regulated by the endocrine system. To come to a better appreciation of the greatness of our God, let us examine more specifically one of the myriad of hormones God has placed within the body—the antidiuretic hormone—and how God uses this simple hormone to control the bodily function of urine production.
Control of body functions
Urine production occurs in the kidneys, governed in part by the antidiuretic hormone. The antidiuretic hormone is secreted from the pituitary gland in the brain, and though passing many cells in its journey within the bloodstream, it communicates only with the cells of the kidneys, directing them in their work of producing urine. Kidneys filter out impurities and toxins from the blood that are byproducts of body metabolism and convert these wastes into urine. Besides removing these toxins, the kidneys also filter out or absorb water from the blood. As the blood passes through the kidneys hundreds of times per day (1.2 L per minute), it produces an amazing 180 L of filtrate. (Imagine 90 2-L pop bottles of filtered fluids and toxin.) About 90% of this filtrate is returned to the blood by various processes in the kidneys, but the other 10% is either converted to urine or returned to the blood at the command of the antidiuretic hormone.
This antidiuretic hormone (ADH) causes the kidney cells to put water back into the bloodstream, thus decreasing the amount of water in urine. Consequently, ADH reduces the amount of urine produced in the course of the day. When ADH is found in the proper levels, approximately 17 L of water are reabsorbed into the bloodstream from the kidneys, producing only 1.5 to 2 L of urine per day. When ADH isunder-secreted, the kidneys will return very little of the water to the bloodstream, producing an enormous amount of dilute urine—up to 24 L per day (equivalent to passing a liter of urine everyhour!). In the presence ofexcess ADH, the kidneys will return almost all the water back to the bloodstream, creating extremely concentrated urine—as little as 0.5 L per day. This concentrated urine has been known to precipitate tiny salt crystals, which slowly and collectively combine into tiny pebbles or stones—called kidney stones. In the providence of God, the delicate balance of water removed from the bloodstream is governed by the amount of ADH that communicates with the kidney cells. This hormone is one of many examples of how God, in His wisdom, has chosen to use these marvelous means to accomplish His purpose in the governing of our daily activities and bodily functions.
A shortage of this tiny hormone molecule has an amazing effect on the body, thereby altering the daily routines of many people. “Diabetes insipidus” is a disorder in which the body does not produce enough ADH. Water that was extracted from the blood by the kidneys is not returned to the bloodstream, since the kidneys were not directed to do so because of an insufficient amount of ADH. Thus, dehydration is the main concern. The afflicted are always thirsty, and they produce great quantities of urine. Without treatment it is very possible for one to die because the delicate water balance needed in the body is not maintained as it should be. In the providence of God, synthetic forms of ADH are being manufactured so that those suffering from diabetes insipidus can get the ADH levels they need to control properly the amount of water in the body and the amount of urine produced each day.
There are other, less serious problems associated with ADH levels in the body. Although not life threatening, these other problems nevertheless significantly affect the daily routines of life. For example, more ADH generally is produced at night (resulting in less urine production) than during the day. This design prevents your bladder from filling completely while you are asleep. In some cases, a lack of ADH at night (either because the pituitary gland does not produce enough or because the kidneys are not able to detect the hormone) will result in large volumes of urine being produced while one sleeps. This necessitates regular visits to the restroom, or, for the young child or “heavy sleeper,” a wet bed.
Besides the nighttime inconvenience that accompanies a shortage of ADH, a person with a regulardaily insufficiency of this hormone may become dehydrated, since water is not being put back into the bloodstream, and therefore is not getting to the cells of the body. Also, chemicals like caffeine and alcohol tend to suppress the secretion of ADH, resulting in less water being returned to the bloodstream, and consequently, a greater volume of urine produced. The use of caffeinated beverages, therefore, enhances the danger of dehydration. This is a serious concern, particularly in the summertime. It is not uncommon for people to drink caffeinated beverages on hot summer days to quench their thirst. This, however, is unwise in that the caffeine will prevent the pituitary gland from secreting ADH. This causes the kidneys to fail to put the filtered water back into the bloodstream, slowly dehydrating the individual.
This illustrates how a simple body function is controlled by a specific hormone. Many more examples of hormones effecting change are found throughout the body. May we see in all this that it is God who speaks and hormones move, either in amounts that bring “normal” body functions or in amounts that lead to difficulties and afflictions. The endocrine system testifies that God governs and controls all things, and does so in a most wonderful and wise fashion.
God’s Wondrous Works
We began the article confessing that Jehovah God, who created all things, has not forsaken the creation, but is intimately involved in the creation, constantly governing and controlling all things. We can sometimes overlook the fact that God governs every tiny creature in the creation—even the molecules that move in the body. These hormones are directed sovereignly by the Word of God each moment of each day in each person of this world. They do not move without His command. And they move where and when He commands. It is by God’s sovereign government that in one person there may be excess hormones, or in another, not enough. God gives us this creation as pictures, or, as the Belgic Confession says, as a most elegant book, in order that we may contemplate the invisible things of God. As we examine how God governs and controls body functions and specifically governs and controls the very movements of the hormone molecules, we may be sure that God will certainly govern and control all the circumstances in our life. We come to this knowledge from Scripture when it commands us to consider the care God has for the birds of the air and the flowers of the field. As God cares for these creatures, including hormones, so much more will He care for us (Matt. 6:25ff.). However, we ought not limit the government of God merely to what we can see physically. God controls allthings—from the minute to the expanse of the heavens, from the “minor” issues to the “major” issues of life, from the physical to the spiritual (read Heidelberg Catechism, LD 1 and 10; Belgic Confession, Art. 13). We ought to take time to examine the beautiful and intricate parts of the creation, observing how God directs all things in creation, and contemplate how God is controlling all things for our salvation. In this His name is glorified!
Our consideration of the work of tiny, often overlooked hormones brings to mind a familiar theme we find when studying the human body. We notice that God places in the human body all sorts of different kinds of members—all of which have a place and function. In fact, the tiniest of members of the body, often unknown and unseen, like hormones, are necessary— very necessary! It is a beautiful picture of the covenant life of Christ and His Body, the church (I Cor. 12). All the members of the body of Christ are necessary and special, even though one’s place or function in the church may not be as obvious or readily observed by others. Even little children in the church are an important and effective witness to the Truth. Truly, “Weakest means fulfill Thy will, mighty enemies to still.” Never should we take for granted the simple means God uses, nor despise the day of small things (Zech. 4:10). Let us bow in humility before God’s wise ways of executing His good and perfect counsel.
All God’s works praise Him! Whether great or small, God’s creatures— the works of His hands— marvelously shout His praises. May we praise Jehovah for this excellent display of His glory found in such a tiny aspect of creation!