‘Endo’ ( within)+ ‘Crinis’ (secrete) Hypothalamus

The endocrine system is composed of General Function: Serves as the link

glands that secrete hormones that travel between the Nervous System and the
through the blood stream to reach its target Endocrine System, it helps maintain
tissues. homeostasis in the body by stimulating or
inhabiting many of the body’s processes.
THERE ARE ATLEAST 50 DIFFERENT
TYPES OF THESE CHEMICAL Hormones
MESSENGERS AT WORK IN YOUR
BODY AT THIS VERY MINUTE.  Growth Hormone-releasing
Hormone ( GHRH )
HORMONES CONTROL AND  Thyrotropin-releasing Hormone
REGULATE: ( TRH )
 Reproduction  Corticotropin-releasing Hormone
 Metabolism and energy balance ( CRH )
 Growth and development  Gonadotropin-releasing Hormone
 Body defense ( GRH )
 General homeostasis including water,  Prolactin
nutrient and electrolyte balance of
the blood
Pineal Gland
Pituitary Gland
Location: below the corpus callosum, in
Location: directly below the
the middle of the brain
Hypothalamus; divided into two: the
Hormone: Melatonin
Anterior and Posterior lobes.
Effect: Helps in the timing of circadian
rhythm’s ( 24-hrs internal clock) and with
Pituitary ( Anterior ) Hormones:
sleep. Being exposed to light at night can
 Growth Hormone ( GH )
block melatonin production.
Over: Too much melatonin can cause  Thyroid-stimulating Hormone
drowsiness and reduced core body ( TSH )
temperature. Very large doses have effects  Adrenocorticotropic Hormone
on the performance of the human ( ACTH )
reproductive system.  Follicle-stimulating Hormone
Under: No known effect on health ( FSH )
 Luteinizing Hormone ( LH )
Pituitary ( Posterior ) Hormones:
Hormones:
- Oxytocin ( OT ) - Calcitonin: decreases blood-calcium
- Antidiuretic Hormone ( ADH ) levels
- Triiodothyronine ( T3 )
Effect: Commonly associated in social - Tetraiodothyronine ( T4 or
behaviors such as sexual arousal, trust, Thyroxine )
attachment, thus, frequently referred to as Effect: Involved in helping to regulate
“Cuddle Hormone”. However, it is also levels of calcium and phosphate in the
responsible stimulates uterine contractions blood, opposing the action of parathyroid
during childbirth and milk ejection. hormone. This means that it acts to reduce
Over: No clear indication as of this calcium levels in the blood m. However,
writing. the importance of this role in humans is
Under: No clear indication as of this unclear, as patients who have very low or
writing, although linked to “ Autism very high levels of calcitonin show no
Spectrum Disorder and depressive adverse effects.
symptoms” Over: No clear indication as of this
writing.
Effect: Its most important role is to Under: No clear indication as of this
conserve the fluid volume of your body by writing.
reducing the amount of water passed out in
the urine. It does this by allowing water in Effect: Regulates the speed with which the
the urine to be taken back into the body in cells/metabolism work. For example, T3
a specific area of the kidney. and T4 regulate your heart rate and how
fast your intestines process food.
Over: Syndrome of Inappropriate Over: Hyperthyroidism: Anxiety,
Antidiuretic Hormone ( SIADH) irritability, nervousness, hyperactivity,
Symptoms include: Nausea or vomiting, hand trembling, hair loss, etc.
Tremors, depressed mood, memory
impairment, etc. Under: Hyperthyroidism: Tiredness, and
fatigue, difficulty concentrating,
Under: Causes the kidneys to excrete too depression, joint and muscle pain, etc.
much water. Urine volume will increase
leading to dehydration and a fall in blood Parathyroid Gland
pressure.
Location: pea-shaped structure at the base
Thyroid Gland of the neck; behind the Thyroid.
Hormones: Parathyroid Hormone
Effect: Increases blood-calcium levels
Location: butterfly-shaped structure at the
through the bones, kidneys, and intestines.
base of the neck; just below the Adam’s
Apple.
Over: Hyperparathyroidism: Depression, pressure, blood glucose, respiration
tiredness, feeling thirsty and frequent and muscle tension in response. It
urination, muscle weakness, etc. also temporarily shuts down the
Under: Hypoparathyroidism: tingling body’s systems that aren’t needed in
sensation in fingertips, toes, and lips; the face of crisis, such as digestion
twitching facial muscles, tiredness, etc. and reproduction.
Parathyroid Glands - Aldosterone
Parathyroid hormone (PTH) Effect: Helps convert fats and proteins
Bones: Release calcium into glucose; Anti inflammatory effect.
Kidneys: Reduce Calcium, clearance, Over: Cushing Syndrome: Red cheeks, fat
Vitamin D activation pads ( buffalo humps), bruise easily,
Intestines: Activated vitamin D helps abdominal stretch marks, pendulous
absorb calcium in gut abdomen, thin arm and leg.
Under: Addison’s Disease: Fatigue,
Thymus dizziness (upon standing), weight loss,
muscle weakness, etc. If left untreated,
Location: upper portion of the chest; could be life threatening.
located behind your sternum, and between
your lungs. Effect: It regulates salt and water in the
Hormone: Thymosin body, thus having an effect on blood
Effect: Stimulates the development of pressure.
disease-fighting T cells, important part of Over: The symptoms include high blood
the immune system. pressure, low blood levels of potassium
Notable Fact: and an abnormal increase in blood volume.
 The thymus is only active until Under: Addison’s Disease: Fatigue,
puberty dizziness (upon standing), weight loss,
 After puberty, the thymus starts to muscle weakness, etc. If left untreated,
slowly shrink and become replaced could be life threatening.
by fat.
Adrenal (Medulla) Hormones:
- Epinephrine
Adrenal Gland - Norepinephrine
Effect: Both epinephrine and
Location: On top of both kidneys; divided norepinephrine can affect your heart,
into two parts: blood sugar levels, and blood vessels.
1. Adrenal ( Cortex): Outer Portion Over : Some people with obesity and
2. Adrenal ( Medulla): Inner Portion untreated obstructive sleep apnea may
Adrenal ( Cortex) Hormones: be e x p o s e d t o h i g h l e v e l s o f
- Cortisol ( Stressed out? This nor adrenaline/adrenaline each night as
hormones is released during times of they struggle to breathe; this might play
stress, increasing heart rate, blood
 a role in the development of high blood  Glucagon
pressure in such people.  Insulin
Under: Suffering from too little 
adrenaline is very unusual, even if you Location: Reproductive organs
have lost both adrenal glands through
disease or surgery. Since 90% of the Hormones
body’s noradrenaline comes from the Ovaries: Estrogen (development and
nervous system, the loss of 10% via the regulation of Female Reproductive Organs
adrenal glands is not really significant. and Secondary Sex Characteristics);
Progesterone (regulates the menstrual
Pancreas cycle and is crucial for pregnancy)

Location: Back of the abdomen, behind Testes: Testosterone (development and

the stomach regulation of Male Reproductive Organs
and Secondary Sex Characteristics).
Hormones:
Hypothalamic-Pituitary Axis (HPA)
HPA directly affects the functions of the thyroid gland, the adrenal gland, and the gonads,
as well as influencing growth, milk production, and others.