Van Buren County RTL

Looking Inside—A Primer On How Our Healthy Bodies Work

(scroll down for pdf download link for the entire newsletter)

By Jack Bley

For the next several issues of this newsletter, I will attempt to explain some of the anatomy, physiology and pharmacology which is essential if we are to understand so many of the reproductive health issues that currently puzzle too many Americans. Topics will include the basic reproductive cycles of women and men, fertilization which produces a zygote which becomes a fetus which becomes a baby human being, contraception, abortion, transgenderism and more. The subjects can, at first, be difficult, to be sure, but if we are to make proper and informed decisions about any aspect of our health and well-being, we must understand ourselves. Please do not hesitate to provide us feedback for clarification, complaints and future topics of interest.

There is an almond-sized area at the base of the brain, just behind the eyes, and just above the roof of the mouth called the HYPOTHALAMUS which is the key focus of our story. Think of it as the Captain of a big ship. The hypothalamus is a neuro-endocrine bridge—it is both nervous and glandular—because it is the communication link between our electrified brains and the chemical hormones both of which send messages throughout our bodies to control our HOMEOSTASIS. Homeostasis is a fancy word for BALANCE, and in order to be healthy and to thrive, our bodies must perform countless balancing acts—or course corrections—throughout the day.

One easy to recognize example of homeostasis is the way we keep our body temperatures stable within a few degrees of normal temperature, 98.4 degrees Fahrenheit. If thermometer-like sensors located throughout the body sense that it is cold, an electrical message is sent using the nerves of the nervous system to the hypothalamus command center which recognizes that the low range of normal has been crossed. It is programmed to respond to the alteration, the cooling, by sending messages to other parts of the body which will answer by creating an effect that reverses the sinking body temperature. These effectors are the muscles which begin to shiver and create heat, and the blood vessels which redirect or shunt blood from the warmer areas to the cooler areas, and maybe even to the hair which becomes erect to attempt to create some insulation (think: goosebumps). On the other hand, when the sensors feel it is getting too hot, opposite effects will occur, but instead of shivering, there may be sweating which results in evaporative cooling.

Does this remind you of the way your home heating and air conditioning system works? If so, then good for you because you are beginning to understand the concept of NEGATIVE FEEDBACK, one of the mechanisms designed into us to keep us in balance. Other easy examples of this balancing act are the way your body controls the levels of glucose (sugar) in your blood before and between meals, and the way you breathe faster or slower during exercise or during rest to control the amount of oxygen and carbon dioxide within you. When the system is working we do not even notice, and we stay healthy, but when the system is broken, we might be sick. Or worse!

Back to our hypothalamus. In the next lesson we will see how our amazing hypothalamus commander—the Captain of our ship—takes continuous input from the brain, from the body and from hormone messengers. The Captain analyzes all that data, then responds by giving orders with signals to the appropriate parts of the body to correct changes that occur keeping our ship afloat and safe. If the Captain determines that our ship is heading in the wrong direction, a course change is made so once again we can enjoy safe passage HOME. HOMEostasis is thus restored.