The two Governors of our body: The Hypothalamus and the Pituitary Gland

The fact that you are able to sit comfortably in your chair and read these sentences is due to systems that organize the internal balance of your body for your benefit. For example, no matter what the temperature outside, your body must always be kept at a constant temperature, usually between 36.5 and 37.5 degrees. A sudden fall or rise in body temperature may result in death. The body temperature of a healthy individual, thanks to these systems, will vary at most 0.5 of a degree. In the same way, the pressure of the blood in the veins, the amount of fluid in the blood, and the speed at which the cells function must be delicately measured, and the existing balance safeguarded at every moment.

Let us imagine the efforts needed to artificially ensure these balances. First, imagine that there exist delicate thermometers in a few places in the body, special devices to measure the density of the blood in the veins, and mini laboratories to control the rate of speed at which the cells function. Then, imagine that all these thousands of tiny devices located in every point in the body must make the right assessments every second and transmit the information they receive to a highly advanced computer.

However, it is not enough that these assessments are made alone; at the same time, it is also necessary to know, according to the available data, which actions must be taken and what kind of command must be given to which cells.

Of course, even with the state of today's technology, it is still impossible to place thousands of thermometers, a mini laboratory, and pressure measuring devices in the depths of the human body. Yet a special system with the finest possible design has been placed from birth deep in the human body.

Thousands of different receivers measure such things as the body's temperature and the pressure in the blood vessels. Then they send this information to a very special computer. This computer is the area of the brain called the hypothalamus.

Your Body's Hidden Manager: The Hypothalamus

The hypothalamus is the general director of the hormone system; it has the vital task of ensuring the internal stability of the human body. At every moment, the hypothalamus assesses messages coming to it from the brain and the depths of the body. Afterwards, it performs a number of functions, such as maintaining a stable body temperature, controlling blood pressure, ensuring a fluid balance, and even proper sleep patterns.

The hypothalamus is located directly under the brain and is the size of a hazel nut. A considerable amount of information relative to the body state is sent to the hypothalamus. Information is transmitted to it from every point in the body, including the sense centers in the brain. It then analyses the information it has received, decides what measures are to be taken, what changes must be made in the body, and causes the appropriate cells of the body to carry out its decisions.

The basic point that must be noticed here is this: the hypothalamus is an organ composed of unconscious cells. A cell does not know how long a human being needs to sleep; it cannot calculate what the body's temperature should be. It cannot make the best decision based on the information at hand, and it cannot make another cell in a far removed area of the body carry out this decision. Yet the cells in the hypothalamus act in an extraordinarily conscious manner to ensure that the necessary balances in the body are maintained. In the pages that follow, we shall examine in detail the remarkable activities displayed by these unconscious cells.

Most of the information about the human body comes to the hypothalamus. The hypothalamus interprets this information, makes the necessary decisions and causes the cells put these decisions into practice. On the left, we see the position of the hypothalamus in the brain. It is the supreme power of God that enables the hypothalamus to make vital decisions.

One of the most important functions of the hypothalamus is to form a bridge between the hormonal system and the other system that controls and oversees the body-the nervous system. The hypothalamus not only directs the hormonal system, but also the nervous system with a high degree of expertise.

The hypothalamus has a very important assistant in its role of governing the body; this assistant informs the appropriate body areas of the decisions that have been taken. For example, when there is a drop in blood pressure, bits of information are set into motion, and these inform the hypothalamus of the change in pressure; then the hypothalamus decides what measures must be taken to raise it and informs its assistant of its decision.

In order to effect the decision, the helper knows which cells must receive the command. It writes messages in a language that these cells can understand and transmits them immediately. The cells obey the command they have received and take the appropriate action to raise the blood pressure.

This assistant to the hypothalamus is the pituitary gland, which also has a very important influence on the hormonal system.

Between the hypothalamus and the pituitary gland there is a marvelous system of communication. These two pieces of flesh actually communicate like two conscious human beings. The hypothalamus has complete control over the pituitary gland and its vital secretion of several hormones.

For example, the hypothalamus of a growing child sends a message to the pituitary gland with the command, "secrete the growth hormone" and the pituitary gland then secretes the growth hormone exactly as needed.

Something similar happens when the cells of the body need to work faster; this time there is a two-stage chain of command. The hypothalamus sends an order to the pituitary gland which, in turn, sends the order to the thyroid gland. The thyroid gland secretes the proper amount of thyroid hormone and the cells of the body begin to work faster.

The location of the hormonal glands under the control of the hypothalamus in the body.

When the adrenal glands (which produce several very important hormones) must be activated or the reproductive organs must produce their hormones, the hypothalamus again sends a message to the pituitary gland, which directs it to the relevant areas and ensures the required hormones in those areas are secreted.

The hormones produced by the hypothalamus to direct the pituitary gland include:

• Growth hormone-releasing hormone
• Thyrotropin-releasing hormone
• Corticotropin-releasing hormone
• Gonadotropin-releasing hormone.

In some cases the hypothalamus, in order to intervene in the activity of the cells, uses two hormones that it has secreted itself. To store these hormones, it first sends them to the pituitary gland, then, when required, it ensures that they are secreted by the pituitary gland. These hormones are:

• Vasopressin (an antidiuretic, i.e., water retaining, hormone)
• Oxytocin

These two hormone molecules produced by the hypothalamus are very small. One of them is only three amino acids large. The hypothalamus hormones are distinguished from other hormones not only by being small; they also differ from other hormones by the distance they cover in the body. Hormones generally travel a long distance from the hormonal gland where they were produced to the designated organ. However, the hypothalamus hormones reach the pituitary gland after passing through only a capillary vessel a few millimeters thick. They never enter the general circulatory system.

The hypothalamus produces the hormones that activate the pituitary gland, and when necessary, it also produces hormones that stop the pituitary gland at the appropriate time from secreting a certain hormone. In this way, it has complete control over the activity of the pituitary gland.

The hypothalamus, which is located right under the brain and is the size of a hazel nut, controls many vital functions such as the regulation of the body's metabolism, the operation of the adrenal glands, the production of milk and the regulation of body's growth. While performing these activities, it employs the other hormonal glands under its command. In the illustration above, we see the hormones that work in conjunction with the hypothalamus. The thought that these little pieces of flesh can communicate with each other like conscious human beings and perform their activities concertedly help humans understand the majesty of God.