Getting to Know Your Glands 101


PCOS OptionsAlmost every patient that walks through the door has a glandular problem.  Our glands are the underlying reason for the majority of our illnesses, conditions, emotional states and even decisions!  In fact, you can blame your glands for everything if you ask me!  Many physicians, including endocrinologists, don't always have a test available to determine if a gland is "off" and even less time to explain to you what it means if your pituitary is weak.  So here's a handy-dandy overview of each of the major players along with their hormones which may give you a clue to the symptoms you feel! So the first thing to know is that what makes a gland is its ability to make and release chemicals called hormones.  Some glands release these hormones into little tubes that carry the chemicals to a particular location (pancrease with digestive enzymes) while others simply squirt their products directly into the blood or surrounding body tissues.  We think of glands as being the big, honking glands like the pituitary and thyroid, but there are also teeny tiny itsy bitsy little glands that can be as small as a few cells.  So the endocrine system is BIG and important.  Just think of a company where memos convey information from department to department and person to person, telling some to do certain tasks and when to do them.  Same thing.

Now the interesting thing about the glands, not that it's much different from other tissues of the body, is something we often forget.  They are alive and they need three things: oxygen, vitamins and minerals and all the building blocks needed to make their hormones.  You can't bake a cake without all your ingredients, or at least it won't taste as good!  For example the thyroid needs iodine both for its own metabolism and to make its hormones.  The adrenal glands use sodium and potassium to stay balanced and active, but they can't make their hormones without essential fatty acids.  Half of the reason women are tired is because they don't take in enough fat for their adrenals to work!  And it has NOTHING to do with the fat on your thighs BTW!

The last thing to consider about the glands is that they all work together which means when one is off, another has to try and pick up the slack, or kick the s**t out of the slow one to get it moving again.  That is why your TSH (thyroid stimulating hormone) goes up when the thyroid is weak.  The pituitary is trying to scream "WAKE UP!!!".  But if the thyroid is comatose, that may not be enough!  Often, the gland in question may actually be secreting plenty of hormone, but it's not getting to its target tissue.  This may be your fault!  Two things affect the movement of a hormone - blood flow (or lack thereof) and carriers.  For instance hormones are either water soluble or fat soluble.  If they are water soluble, then you need to have enough water in the blood.  More water in the blood combined with relaxed muscles makes for more circulation, so hormones get to their destinations easily.  This is not the case if your blood flow is like 5:30 on the Tobin bridge, and if your muscles are too tight from stress, then it's like only one lane is open at the tolls!  If a hormone is fat soluble, then you need enough dietary fat as well.  A secret thing to consider is that if your blood cholesterol level is too high, your fat soluble hormone level might be too high, driving up your cholesterol need.

So let's begin with the Hypothalamus which is the major link between the nervous and endocrine systems. The hypothalamus with the pituitary, virtually control all aspects of growth, development, metabolism and homeostasis. Hormones in the anterior section of the pituitary are controlled by releasing or inhibiting hormones produced by the hypothalamus. For this reason, the pituitary is called the "master gland" of the body and it is completely controlled by the chemical signals it receives from the hypothalamus.  The hypothalamus is behind the thalmic portion of the brain and contains links within itself to all the aspects of the brain and nervous system that identify STRESS and initiate emotional responses to all the wonderful situations you deal with daily.  It is here that stress becomes chemical, and cascade down through the endocrine system to control all your essential body responses and functions including breathing, digestion, muscular contraction, inflammatory control, immunity and even your libido.

The hypothalamus doesn't really lift a finger to do anything, except to send a message to the pituitary gland.  So the hypothalamus makes all the decisions, and the pituitary gland is really the go to guy for the hypothalamus to ensure that the instructions are delegated to the glands and carried out for the benefit of the body.  The chemical signals secreted by the hypothalamus are therefore only for the eyes and ears of the pituitary, so they are carried directly to the pituitary through special veins.  Nothing like your own direct hallway!

Because the hypothalamus is the link between your external environment and your internal responses, it is strongly affected by how the nervous system is handling things.  For this reason, simply working on all the employees of the hypothalamus can have a profound indirect effect on it as the head honcho.

So the pituitary is a pea-sized structure and sits inside your sphenoid bone behind your forehead.  It has two parts, the anterior and the posterior (front and rump for those of you who don't bother with the dictionary).  The anterior is by far the more multi-tasking of the two containing many different types of cells that each are responsible for a different hormone.  It loves vitamin E and the mineral manganese which is why manganese is known as the "mothering" mineral because of all the reproductive hormones controlled by this part of the pituitary.  A weakness of the anterior pituitary can affect a LOT because it makes the following:

Growth hormone (hGH) - targets the liver and adipose (fatty) tissue.  Indirectly promotes growth, controls protein, lipid and carbohydrate metabolism.

Thyroid-stimulating hormone(TSH) - targets the thyroid gland.  Stimulates secretion of thyroid hormones.

Adrenocorticotropic hormone (ACTH)- targets the adrenal gland cortex.  Stimulates the secretion of glucocorticoids.

Prolactin - targets the mammary gland.  Stimulates milk production.

Luteinizing hormone (LH) - targets the ovaries and testis.  Controls reproductive ability including sperm production, testosterone, estrogen and progesterone levels.

Follicle-stimulating hormone(FSH) - targets the ovaries and testis.  Controls reproductive ability including sperm production, testosterone, estrogen and progesterone levels.

Melanocyte-stimulating hormone (MSH) - targets the skin. Controls the release of melanin.

Now the posterior part of the pituitary only has two hormones that it is responsible for:

Antidiuretic hormone (ADH) - targets the kidneys, small arteries and sweat glands. Decreases urine production in order to retain body water. It does this by increasing water retention in the kidneys and decrease skin circulation, thus lessening sweat released from the sudoriferous glands. At high levels, ADH will cause an increase in blood pressure.

Oxytocin - targets the uterus and mammary glands.  Stimulates the release of milk and contractions of the uterus during childbirth.

Now on to the ones we always think about.  The Thyroid gland is located just below the larynx (think of where you feel vibration when you talk), with lobes on either side of the trachea. The thyroid is the only endocrine gland that stores its secretions in large 100-day supplies, while most glands only store a short supply because they are needed in short bursts. Thyroid hormones regulate oxygen use and basal metabolic rate, cellular metabolism and growth and development. The activity of the thyroid is controlled in two main ways: by the level of iodine in the thyroid gland and by negative feedback systems involving both the hypothalamus and the anterior pituitary gland.  The thyroid is paired up with the Parathyroid (discussed below) and uses iodine as its mineral of choice.  Although we seem to put so much emphasis on the thyroid, it actually only releases three hormones:

Triiodothyronine (T3) and Thyroxine (T4) - increase basal metabolic rate, stimulate synthesis of proteins, increase use of glucose for ATP production, increase the excretion of cholesterol in bile and accelerate body growth.

Calcitonin (CT) - lowers blood levels of calcium and phosphates by inhibiting breakdown of bone matrix by osteoclasts and accelerating uptake of calcium and phosphates into bone matrix.

The thyroid hormones T3 and T4 are the only major biochemical molecules known to include iodine, so the levels of iodine available to the thyroid are incredibly important.  T4 is the inactive form which is then converted into T3, the active form.  This conversion takes place in the thyroid itself as well as the brain, liver, blood and other tissues.  This conversion process is regulated by the mineral selenium combined with proteins.

The Parathyroid glands are often overlooked, but it is critical for calcium metabolism and the health of your bones.  You have four parathyroid glands which are located behind your thyroid in the neck, although there have been some freaks of nature who have them in their chest.  They secrete parathyroid hormone (PTH) which is an antagonist to calcitonin secreted by the thyroid gland.  Sensors in the parathyroid glands are triggered when your blood calcium levels drop.  This causes the release of PTH which then begins the process of bone breakdown so that your blood calcium levels will rise to normal levels.  It also increases the absorption of calcium from the gut and signals the kidneys to conserve calcium.  So, osteoporosis the diagnosis?  Look to your parathyroid glands!

Next we move on to the Adrenal glands.  These are the glands that are essential for your day to day stress - handling capability.  Just imagine that rush of anxiety?  That's your adrenals kicking in.  These glands adapt to our environment and our sensory awareness.  You have two, one on top of each kidney, and like anything that's at the top of the heap, they control the function of the kidneys with a complex group of hormones.  Each adrenal gland controls hormones based on two sections, the inside of the gland called the medulla and the outside layers of the gland called the cortex.

The hormones of the adrenal cortex are released after stimulation by ACTH secreted from the pituitary.  These hormones are steroids and are made from cholesterol.  There are three groups of these hormones:

Glucocorticoids - these hormones raise the level of blood sugar or glucose.  This process involves the liver and skeletal muscles where stored sugars (glycogen) can be accessed and converted into glucose.  These have a strong anti-inflammatory effect on the body and depress immune response.  The most notable hormone in this group is Cortisol which stimulates glucose synthesis and inhibits glucose uptake in tissue, stimulates fat breakdown in adipose tissue to create glucose.  It is strongly anti-inflammatory and immunosuppressive.

Mineralocorticoids - these hormones get their name from their effect on mineral metabolism.  This is mainly Aldosterone which increases the volume of blood in the body by reabsorption of sodium in the kidneys.  Stimulates the kidneys to release potassium and hydrogen ions which relax circulatory pathways.

Androgens - the most well known is DHEA which are the core of libido in females and are the source of estrogens for post-menopausal women.  It also controls the growth of hormonal hair in men and women.

So now we turn to the medulla of the adrenal glands.  The medulla is stimulated by acetylcholine which is released by nerves, so it is strictly in relation to stress.  In the medulla two important hormones are produced and released:

Epinephrine & Norepinephrine - these produce effects that ramp up the action of the nervous system during stress, affecting breathing, heart rate, blood flow, etc.

The Pancreas (sounds like a train station in London) is quite an interesting gland because it controls two completely different aspects of the body, digestion and blood glucose.  Most people only think of it in relation to blood glucose, but its function in digestion is vital.  It shares the bile duct with the gall bladder, so often a problem with one affects the other.  The pancreas seems HUGE when you compare it to other organs, so it's quite amazing that it says something about the importance of its function. We still don't completely understand the subtle song and dance that these four hormones do together:

Glucagon - raises blood glucose levels by increasing the breakdown of stored glycogen in the liver and converting other nutrients into glucose.

Insulin - lowers blood glucose by accelerating the transport of glucose into cells, converting glucose to glycogen for storage and decreasing production of glucose.  Secondarily it increases fat storage and the synthesis of protein.

Somatostatin - this overrides the release of the first two hormones above and shows down the absorption of nutrients from the digestive tract.

Pancreatic polypeptide - this inhibits somatostatin and slows down the gallbladder and the secretion of the digestive enzymes of the pancreas.

Now the digestive function of the pancreas is amazing.  Pancreatic juice contains a group of digestive enzymes that break down starches, proteins and triglycerides.  It enters the digestive tract through the bile duct and interacts with the enzymes of the brush border.

Now the Gonads which include Ovaries in women and Testicles in men (generally) are glands that we totally take for granted.  The ovaries are most active during reproductive years and release estrogen and progesterone, as well as inhibin (inhibits the release of FSH) and relaxin (eases the pelvis during childbirth).  The testicles produce testosterone which is the primary androgen hormone.  All of these are important for the regulation and maintenance of libido, strength, and reproductive health.

The Pineal gland is another one that is often overlooked.  It is located in the center of the head just above the roof of the mouth which means it can be affected by any jaw issues or intense dental work.  Just imagine how the vibration of shouting would affect it?!  The pineal gland secretes melatonin when exposed to darkness, which is what makes you sleepy.  Exposure to light shuts down melatonin production, so you wake up.  Often insomnia and fatigue may be linked to a problem with your melatonin production and your pineal gland.  For example, a lack of norepinephrine from the adrenal glands can cause excessive secretion of melatonin, making you tired all the time, while exposure to artificial light late at night can keep you up.

The Thymus gland is involved in immunity.  It is located directly behind the breast bone (sternum) and produces a group of hormones that control T cells (a type of white blood cell) which destroy microbes and toxins and may also have a role in the aging process.

So now that you are a little more familiar with your glands, it might be a little easier to understand your symptoms.  For instance if you have low blood pressure, you might want to look at the adrenal glands, but with high blood pressure, the kidneys would be most likely culprits.  Low sex drive may have nothing to do with the gonads, but might be the result of low DHEA from the adrenal glands.  If you suspect your glands, then start focusing on what makes the most sense and get more information.

You may know more than you think!