Endocrine system

Figure 1. Glands of the Endocrine system

The endocrine system is the system of specialized organs called glands, each of which secretes a type of chemical called a hormone directly into the bloodstream to regulate the body. Hormones have many different functions and modes of action; one hormone may have several effects on different target organs, and, conversely, one target organ may be affected by more than one hormone.

Hormones regulate and influence:

• Weight Regulation
• Your Immune Function
• Body Fat Composition
• Energy Levels
• Anti-aging
• Regulating Mood
• Sexual Function
• Reproductive Processes
• Growth rate
• Tissue Function
• Metabolism

The hormones secreted by the endocrine system are classified into three categories based on their chemical structure:

1. Steroids – these hormones are lipids made from cholesterol, such as sex hormones. They come from the testis (male), ovaries (female), adrenal glands and placenta.
2. Peptides –  are short chains of amino acids that are secreted by the pituitary gland, parathyroid gland, heart, stomach, liver, and kidneys.  Most hormones are peptides.
3. Amines – these are made from an amino acid secreted from the thyroid gland and adrenal glands.

glands	HORMONES	GLAND/HORMONE FUNCTION	SOME DISORDERS
Hypothalamus (Lower middle of the brain)	Growth hormone-releasing hormone (GHRH) Thyrotropin-releasing hormone (TRH) Corticotropin-releasing hormone (CRH) Gonadotropin-releasing hormone (GnRH) Prolactin-(PRL) Antidiuretic Hormones- (ADH)	Communicates with both nervous and endocrine systems. Stimulates (GHRH, TRH, CRH, GnRH) or inhibits (PIF) hormone production in the pituitary Water balance	Precocious puberty (early GnRH production) Kallman syndrome (inadequate GnRH production)
Pituitary (below hypothalamus, behind sinus cavity)	Prolactin Growth Hormone ACTH TSH LH, FSH	Milk production Bone growth Stimulates cortisol Stimulates thyroid Regulation of testosterone and estrogen, fertility	Hypopituitarism    Empty Sella Syndrome    Galactorrhea Acromegaly or Gigantism (excess GH) Growth Hormone Deficiency (GHD) Cushing disease (excess ACTH) Hyper/Hypothyroidism (TSH) Loss of menstrual period Loss of sex drive Infertility
Thyroid (butterfly shaped, Lies flat against windpipe in the throat)	T4 (thyroxine) T3 (triiodothyronine) calcitonin	Metabolism Regulate blood in calcium	Thyroid diseases (including hypo and hyperthyroidism)
Parathyroid (located above or next to thyroid)	Parathyroid Hormone (PTH)  or Parathormone		Hyperparathyroidism Hypoparathyroidism
Adrenal    (2 organs on top of kidneys)	Epinephrine Norepinephrine Aldosterone  Cortisol	Blood pressure regulation stress reaction Salt, water balance Stress reaction	Pheochromocytopenia(MEN2) Conn syndrome Cushing syndrome Addisons disease
Ovaries (located on the pelvis)	Estrogen Progesterone	Female sexual characteristics	Polycystic ovary syndrome (PCOS)
Testes (located in the groin)	Testosterone	Male sexual characteristics	Hypogonadism
Pancreas (located behind the stomach)	Insulin Glucagon Somatostatin	Glucose regulation	Diabetes mellitus MENI Zollinger-Ellison syndrome
Pineal (lower side of the brain)	Melatonin	Helps control sleep patterns

References:
http://en.wikipedia.org/wiki/Endocrine_system
http://kidshealth.org/teen/your_body/body_basics/endocrine.html#
http://www.buzzle.com/articles/endocrine-system-function.html