Last week’s discussions on hormones got me hooked on the endocrine system, so I figured we take a little closer look at some of its components this week before delving deeper into the pancreas and its hormones (glucagon and insulin); so you can think of September as Endocrine Month. Today we will start the endocrine system week off, with the control center (naturally I’m talking about the brain here). First there is the pituitary gland, which usually gets the credit for hormone control, but it is the hypothalamus that we’ll discuss next that does the dirty work! What I find so intriguing (I’m fascinated by the brain anyway), is that we are talking about tiny little glands in the body, but they do and control so much in our lives. The pituitary gland is about the size of a pea and the hypothalamus is the size of an almond! Wow, what do they do exactly? First we’ll cover a little anatomy so we can grasp a better picture in our minds of what’s occurring. The Pituitary gland is situated, as you can see from the picture, below the hypothalamus. It is composed of two lobes: the anterior lobe and the posterior lobe. The hormones that it secretes (thanks to signals from the hypothalamus) regulate other glands of the endocrine system, including: thyroid, adrenal glands, ovaries, testes.Of course the two lobes are very different and produce different hormones. The hormones of the anterior lobe produce:
- ACTH (stimulates the adrenal glands)
- FSH (function of the ovaries and testes)
- GH (growth and maintenance)
- LH (ovaries and testes, working with FSH)
- Prolactin (breast milk production)
- TSH (stimulate the thyroid gland)
The posterior lobe contains nerves from the hypothalamus. It sends hormones through these nerves and then the posterior lobe releases them. These hormones are: ADH (water absorption) and oxytocin (childbirth and milk production). So as you can see the pituitary has a bit of a reputation and has its hands all over the endocrine system, leaving hardly any gland left untouched.
Proceeding on to the hypothalamus. This wonderful gem of the brain is helps with homeostasis (fancy for balance in the body), but is also the link between the nervous system and the endocrine systems. It receives signals from the nervous system telling it to inhibit or stimulate neaurohormones to the pituitary gland with hormone instructions. Some of these hormones include: ADH (water absorption), CRH(adrenal hormones to regulate metabolism and immune function), GnRH (stimulate LH and FSH), GHRH or GHIH (either promote HG or inhibit), oxytocin, PRH and PIH (promote or inhibit prolactin). As you can guess from all the hormones it covers, the hypothalamus deals with a lot of body responses:
- heart rate and blood pressure
- body temperature
- fluid and electrolyte balance
- appetite and weight
- glandular secretions stomach and intestines
- sleep cycles
How do you maintain brain health and all of these functions? Check out last Tuesday’s post on hormonal eating, but being in balance will help with optimal hormones levels (as will stress management and sleep). For more on our fat burner weight loss programs check out our website at bodychange.net. Check in tomorrow when we’ll cover the thyroid!