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What are hormones and

why are they so important?

Hormones, in their most basic sense, are chemical messengers. Hormones are released from glands in the body and travel through the blood stream to send messages to other cells.

All of the cells in our bodies have specific hormone receptors. The receptors are unique for each hormone (like your car key for your starter). Once the hormone binds correctly to its own receptor, a process known as signal transduction occurs. This is like the electronic coming on in the car once the starter motor recognises your key.

In the cell, signal transduction heralds the expounding of the ‘personality’ of that hormone on the cell. For example, when insulin attaches to its receptor called the Insulin receptor, signal transduction occurs. This is a sequential lighting up of intracellular insulin signaling molecules which result in a range of cellular functions like activating the glucose transporter (GLUT-4) to open a gate at the cell surface and bring glucose into the cell lowering blood glucose levels. Insulin has many other actions on a cell including growth and proliferation

The main function of endocrine glands is to secrete hormones directly into the bloodstream. Hormones are chemical substances that affect the activity of another part of the body (target site). In essence, hormones serve as messengers, controlling and coordinating activities throughout the body from your metabolism and fertility to hair growth and how often you have to go to the bathroom.

For women, estrogen (or estradiol) is the main sex hormone. It causes puberty, prepares the body and uterus for pregnancy, and regulates the menstrual cycle. During menopause, estrogen level changes cause many of the uncomfortable symptoms women experience.
Progesterone is similar to estrogen but is not considered the main sex hormone. Like estrogen, it assists with the menstrual cycle and plays a role in pregnancy.

Cortisol has been called the “stress hormone” because of the way it assists the body in responding to stress. This is just one of several functions of this important hormone.
Melatonin levels change throughout the day, increasing after dark to trigger the responses that cause sleep.

Testosterone is the main sex hormone in men. It causes puberty, increases bone density, triggers facial hair growth, and causes muscle mass growth and strength.

When they are in proper balance, hormones help the body thrive, but small problems with hormones can cause serious and life-altering symptoms.

The main hormone-producing

glands are:


The hypothalamus is responsible for body temperature, hunger, moods and the release of hormones from other glands; and also controls thirst, sleep and sex drive.


This gland produces the insulin that helps control blood sugar levels.


Considered the “master control gland,” the pituitary gland controls other glands and makes the hormones that trigger growth.


This gland controls the amount of calcium in the body.


The thyroid produces hormones associated with calorie burning and heart rate.


Also called the thalamus, this gland produces serotonin derivatives of melatonin, which affects sleep.


Only in men, the testes produce the male sex hormone, testosterone, and produce sperm.


This gland plays a role in the function of the adaptive immune system and the maturity of the thymus, and produces T-cells.


Adrenal glands produce the hormones that control sex drive and cortisol, the stress hormone.


Only in women, the ovaries secrete estrogen, testosterone and progesterone, the female sex hormones.

Written by Robyn W. Jacobs, MD

Why are Hormones

so important?

There are three major hormones in our bodies; Insulin, Adrenaline and Cortisol.
They are considered major because if they were to disappear we would not be able to survive for more than a few hours to days. Loss of the minor hormones, on the other hand, would not cause our immediate demise but will cause us to fell pretty lousy and may contribute to disease which could rob us of good health and longevity. Some of these hormones are thyroid, estrogen (actually a family of hormones including estradiol, estriol and estrone), progesterone, testosterone, growth hormone, and DHEA. Each hormone, both major and minor, plays a role in the delicate balance of our metabolism.

In simple terms our metabolism is how we build or use our body. When we eat, sleep, or meditate our metabolism is in an anabolic (or building) state. When we are anabolic, our bodies are regenerating – building new proteins, muscle fibers, blood cells, skin cells, etc. When we exercise, work, or think we turn our metabolism into a catabolic (or using) state. When we are catabolic we are using up the protein, energy and bio- chemicals in our bodies in order to change our external environment in some way. If we do not maintain an appropriate balance between the anabolic and catabolic states (i.e. not getting adequate nutrition or rest), or if we are missing a hormone or have low levels of a hormone, our metabolism becomes imbalanced. Over time, an imbalanced metabolism leads us to feel poorly and can contribute to chronic disease.