Endocrine glands are organs that secrete hormones.
The term endocrine was coined by Starling to contrast the actions of hormones secreted internally i.e directly into blood (endocrine) with those substances secreted externally (exocrine) or into a lumen, such as the gastrointestinal tract.
The term hormone is derived from the Greek verb hormao, which means “to set in motion.” This phrase captures the dynamic properties of hormones and their ability to elicit a cascade of physiologic responses by acting on specific target tissues.
The general peopleare more familiar with the term hormone and with particular disorders of the endocrine system like diabetes, thyroid disorders, PCOS, osteoporosis, growth disorders, etc. However they are often not aware of the term endocrinology and what role an endocrinologist serves.
Endocrinology is a branch of medicine that concerns the study of hormones and its disorders.
Endocrinologists are doctors who specialize in study of hormonal diseases like diabetes, thyroid disorders, growth disorders, etc.
The principal endocrine glands
1. Pituitary Gland
2. Thyroid gland
4. Adrenal Gland
5. Parathyroid gland
6. Gonads – ovary and testis
7. Besides hormones are secreted by various other organs like brain (hypothalamus), heart, kidney, gut, placenta, breasts, etc.
The pituitary is considered as a master gland and governs the function of other endocrine glands in the body.
Types of endocrine disease
Broadly speaking, endocrine disorders may be subdivided into three groups:
1. Endocrine gland hyposecretion (leading to hormone deficiency e.g. hypothyroidism)
2. Endocrine gland hypersecretion (leading to hormone excess e.g. hyperthyroidism)
3. End organ resistance to action of hormone (insulin resistance contributing to type 2 diabetes mellitus)
4. Tumours (benign or malignant) of endocrine glands
5. Inflammation of endocrine glands (e.g. thyroiditis, hypophysitis, etc.)