Each hormone has a different shape as it has to be able to "dock" into the "receptor site" of the target organ. Not only does this hormone have to "dock" into the receptor site but it also has to "turn" like a key.

You’ve probably experienced this. You have a key that goes into the lock perfectly but won’t turn because it's the wrong key? In the same way, these hormones have to "dock" and "turn" to fully complete their task or to "open the door".

That’s why synthetic hormones can cause problems. The hormones can "dock" but can’t "turn" the "key". It is vital for a healthy body that these "keys" can turn so that the proper hormones can be sent to the target organs to carry out the hundreds of body functions such as sleep, digestion, energy, metabolism, falling pregnant, delivering the baby, controlling weight etc.

Some hormones come in "opposing" pairs or what is known as antagonistic pairs. In other words, they oppose each other. For example, if your blood sugar goes too high, insulin (a hormone) will tell your liver to lower your blood sugar but if it drops too low, glucagon (another hormone) will tell your liver to raise your blood sugar.

This is so your body can maintain an optimum balance known as homeostasis. Homeostasis is the ability or tendency of an organism or cell to maintain internal equilibrium – balance - by adjusting its physiological processes regardless of external influences. Your body will do everything it can to maintain homeostasis.

The Different Glands of the Endocrine System

Listed below are the glands that form part of your endocrine system. More about each one will be covered in future articles.

1. Hypothalamus

2. Pituitary

3. Pineal

4. Thyroid

5. Para-thyroid

6. Adrenal

7. Thymus

8. Pancreas (partly gland, partly organ)

9. Gonads (ovaries and testes)

Good Health

Constantly living under conditions of stress, excesses, trauma, hazards, pollution, drugs (medical and other) and chemicals eventually weakens and undermines the efficient functioning of these glands. So, let’s get to understand their functions.

Hormones are very powerful chemicals and when they are in sync and in the right quantity, the body purrs. These tiny glands are small wonders and they need to be in good working condition to maintain good health.

The Master Hormone Gland – The Pituitary - And Its Connector – The Hypothalamus

The hypothalamus is a portion of the brain that links the nervous system to the endocrine system via the pituitary gland. It is called "hypo"-thalamus because it is below the thalamus which is an area of the brain where pain and other sensory information is interpreted and recognized.

The secretion of hormones from the anterior (front portion) pituitary is controlled by the production of hormones by the hypothalamus, which can be split roughly into two main types of hormones:

• hormones that tell the pituitary to switch on production of a hormone (a releasing hormone); and

• hormones that tell the pituitary to switch off production of a hormone (an inhibiting hormone)

The hormones secreted by the posterior pituitary are produced in the hypothalamus and then passed down a tube between the hypothalamus and the pituitary (the pituitary stalk) from whence they are then secreted into the blood.

The hypothalamus' hormones cause smooth muscle to contract, control water balance, are responsible for breast milk, the body's temperature control, gastric reflexes, maternal behavior, blood pressure, feeding, immune responses. They're also responsible for manufacturing neurotransmitters that allow the messages to be passed along the nervous system.

The pituitary puts out hormones that break down stored fat, increase the production of protein and muscles, and stimulate all junior glands such as the ovaries, testicles, thyroid and adrenals. It also contracts the uterus during childbirth and stimulates milk production.

The pituitary is known as the master gland, the top executive of your hormonal system. It is no larger than a pea, is located in the brain and has two sections called the anterior and posterior - anterior means toward the front and posterior towards the back. These two sections of the pituitary gland produce a number of different hormones which act on different target glands or cells. More to follow.