Download ACP Level 2 Lesson Six

ACP-2 Lesson Six
Endocrine System
The endocrine system
plays a vital part in every
aspect of our health. It is
made up of a series of
glands
which
secret
hormones to influence
every one of the bodily
systems.
The glands which are
involved in system are:

Adrenal glands

Pituitary

Hypothalamus

Thyroid

Thymus

Parathyroid

Pineal

Ovaries and testes

Islet of Langerhans
An initial danger signal is
processed in the brain by
the hippocampus, which is
then passed onto to
theamygdala. There, the
signals are changed to
pictures and sounds and is
then sent to thehypothalamus which triggers the HPA axis. The HPA axix stands for:
hypothalamus, Pituitary and Adrenals.
The Adrenals
These small glands sit on top of each of your
kidneys and are in charge of the body’s responses to danger signals or excitement. We
call this the “Fight and Flight” Syndrome. It works extremely quickly and can result in
reactions like a person jumping out of the way of the car without even realizing they
even saw it coming.
The adrenals then secrete epinephrine or what you may be more familiar with
as adrenaline. This causes the heart rate to increase, flushing the muscles with blood,
while breathing gets shallower filling the blood with oxygen. Tiny muscles in the hair
follicles called erector pili are activated causing the hairs on your skin to stand on end.
Once the initial stress response has passed, the parasympathetic nervous system then
applies the brakes and the hormones return to normal.
The reason for this chain of responses enables to rise to a fight very quickly if we need
to protect ourselves and/or supercharge us to give our best performance.
In fact, the adrenals are responsible for activating over a 100 different hormones.
Another hormone, you as an aromatherapist should be concerned with is called cortisol.
This particular hormone controls:
• Blood sugar (glucose) levels
• Fat, protein and
(gluconeogenesis)
carbohydrate
• Immune responses
• Anti-inflammatory actions
• Blood pressure
metabolism
to
maintain
blood
glucose
• Heart and blood vessel tone and contraction
• Central nervous system activation
The problem a person face’s is that long term, the parasympathetic system is no longer
able to apply the brakes and the body is flooded with cortisol needlessly which affects
all of the above. You can see why stress-related illnesses can become not only
problematic, but also diverse.
Pituitary
Scientists originally thought the pituitary was
responsible for the control of the endocrine system. We now know that, in fact, the
hypothalamus is the big boss. The pituitary is about the size of a pea and is located
close to the base of the brain.
The pituitary secretes many hormones, but
they do not all exclusively pertain to
sexuality and fertility.
ACTH - Stimulates the adrenal gland to
produce a hormone called cortisol.

TSH
– (thyrotrophin) Stimulates the
thyroid gland to secrete its own hormone,
which is called thyroxine.

FSH Follicle
stimulating
hormone- stimulates the ripening of ova to
be released in ovulation. Encourages
maturation of testosterone in men.


LH Luteinising hormone –triggers ovulation in women and in men helps with the
production of testosterone

Testosterone- Controls reproductive functioning and sexual characteristics. While this
is in higher concentration in men, it is also found in women.

Prolactin – Stimulates the breasts to produce milk. This hormone is secreted in large
amounts during pregnancy and breast feeding, but is present at all times in both men
and women.

Growth hormone or Somatotropin – Stimulates growth and repair in every cell of the
body.

MSH

Vasopressin- Controls the blood fluid and mineral levels in the body by affecting water
retention by the kidneys. This hormone is also known as argenine vasopressin (AVP).

Oxytocin
Affects uterine contractions in pregnancy and birth and subsequent
release of breast milk.
These hormones will be covered in more detail in the lesson about reproduction.
Melanocyte-stimulating hormones – stimulates the growth of nails and hair
Hypothalamus
As you know, this is the CEO
of the endocrine system
which not only controls
everything, but it also
communicates the messages
from the brain into the
physical body. It is located
right at the very base of the
brain and merges with the top
of the spinal cord. It joins
with the pituitary gland by a
thin stalk of neurons and
works like a valve to regulate
the pituitary hormones. Every
message coming from the
brain
passes
through
the hypothalamus.
It governs the process we
call homeostasis, which means it monitors the body to make sure it is ticking along as
it should. It regulates:

body temperature

thirst

hunger

sleep

circadian rhythm

moods

sex drive

water levels
Working from a benchmark set point, the hypothalamus is always checking levels of the
above and then releasing other hormones to try to balance out to ensure everything is
working properly.
Thyroid
The thyroid is a butterfly-shaped organ found in your neck just above the windpipe.
Normally, it is not visible from outside of the throat but certain conditions such
as goitre will cause it to enlarge.
The functions of the thyroid are:

Regulation of appetite

Regulation of temperature

Metabolism

Growth and development
The main hormones secreted by the thyroid are:

thyroxine (T4)

triiodothyronine (T3)
In the blood, T4 is a precursor to T3 and is found in quantities which outstrip T3 by
around 20 to one. This is mainly because T4 has a far longer half-life (the time it takes
for the chemical to break down) than T3.
T4 and T3 are mainly, but not exclusively concerned with metabolism and so if there is
a deficiency you are likely to see weight gain and conversely if there is an excess, you
may struggle to gain weight. A deficiency also will case the patient to feel cold.
For the thyroid to function effectively, it must have enough iodine in the blood. If it
doesn’t, it becomes enlarged and goitre presents itself. Nowadays this is a condition
rarely seen, but it used to be referred to as Derbyshire Neck because it was so prevalent
in this region of England. It was only when the authorities discovered their water was
iodine deficient that a correlation was drawn. Should a person have an over-enthusiastic
thyroid, it is possible they could develop Graves’ Disease.
Thyroid problems cause an especial threat to newborns and most children are now
routinely checked. Problems with this gland can lead to problems with growth, in
particular dwarfism or with mental retardation with the extremely unkind name of
cretinism. A child with an inactive thyroid is unusually quiet, has very little appetite
and will sleep for very long periods.
Thymus
The thymus is found posterior to the sternum in the middle of the chest just in front of
the heart. The role of this gland sits squarely in the immune system. It is here the
important T-Cells mature.
Parathyroid
Parathyroid is found just behind the thyroid gland and is responsible for looking after
the bone density in your body through regulation of calcium and phosphorous. In fact,
there are four of these glands, typically about the size of a grain of rice, and sometimes
as big as a pea. They are mustard yellow in color.
Calcium, in fact, is the only mineral in the body which has its own built-in regulator.
This is because it provides the electrical impulses which transmit along nerves, as well
as contributes to bone density and a person’s mood.
Phosphorous helps keep our teeth strong, but also helps with how the body processes
glucose and with how it metabolizes calcium and protein.
Pineal
Many of you will have seen pictures of the third eye in the center of the brow. This is
the location of the pineal. In fact, it is hidden deep inside the brain where the two
hemispheres meet.
Its function is to produce melotonin which regulates the body’s circadian rhythms. One
particular problem with this might be SAD or seasonal affective disorder, producing too
little, leading to anxiety, too little sleep and depression.
Ovaries and Testes
The male and female hormones will be covered in more detail in the reproduction
lesson, but at this point it is enough to know they are endocrine glands.
Islets of Langerhans
Like the thymus, this is mainly immunity related. The islets (pronounced eye-lets) are
actually lots of clusters of cells, around 4000 clusters in total. Their job
predominately, is to recognize and regulate sugar in the blood stream. They are -2%
of mass of the pancreas.
There are 5 component cells.

Alpha cells producing glucagon (15–20% of total islet cells)

Beta cells producing insulin and amylin (65–80%)

Delta cells producing somatostatin (3–10%)

PP cells (gamma cells) producing pancreatic polypeptide (3–5%)

Epsilon cells producing ghrelin (<1%)
Glucagon
Glucagon is a hormone in the blood stream which increases blood sugar concentration.
It does the opposite to insulin.
Insulin
Insulin, which many are familiar with, regulates carbohydrates and fats in the body. It
absorbs blood sugar into the skeletal muscles and into the blood.
Amylin
This works in tandem with insulin, slowly reducing gastric sugars.
Somatostatin
Somatostatin regulates glucogen and insulin.
Pancreatic polypeptides
Pancreatic polypeptides regulate the secretions from the pancreas and also influences
how the liver processes glycogen as well as the secretions in the gastric processes.
Ghrelin
Ghrelin is known as the hunger hormone and directly communicates with nerves in the
system. It also plays an important role in how efficiently our body uses the energy we
give it.
In summary, the cell clusters also influence each other through hormonal feedback in
a continuous loop.

Glucose/Insulin: activates beta cells and inhibits alpha cells

Glycogen/Glucagon: activates alpha cells which activates beta cells and delta cells

Somatostatin: inhibits alpha cells and beta cells