Hormones

Endocrine glands are the glands which synthesize and release the classical hormones into the blood. The endocrine glands are also called ductless glands because the hormones secreted by them are released directly into blood without any duct.

Major endocrine glands are :

HORMONES SECRETED BY MAJOR ENDOCRINE GLANDS
ANTERIOR PITUTARY	Growth hormone Thyroid stimulating hormone Adrenocorticotropic hormone Follicle stimulating hormone Luteinizing hormone Prolactin
POSTERIOR PITUTARY	Antidiuretic hormone Oxytocin
THYROID GLAND	Thyroxine Tri iodothyronine Calcitonin
PARATHYROID GLAND	Parathormone
PANCREAS-ISLETS OF LANGERHANS	Insulin Glucagon Somatostatin Pancreatic polypeptide
ADRENAL CORTEX	Mineralocorticoids- 1. Aldosterone, 2.11deoxycorticosterone Glucocorticoids- Cortisol Corticosterone Sex hormones - Androgens Estrogen Progesterone
ADRENAL MEDULLA	Catecholamines Adrenaline Noradrenaline Dopamine

HORMONES SECRETED BY GONADS
TESTIS	1. Testosterone 2. Dihydrotestosterone 3. Androstenedion
OVARY	1. Estrogen 2. Progesterone

HORMONES SECRETED BY OTHER ORGANS
PINEAL GLAND	1. Melatonin
HEART	1. Arial natriuretic peptide 2. Brain natriuretic peptide 3. C type natriuretic peptide
THYMUS	1. Thymosin 2. Thymin
PLACENTA	1. Human chorionic gonadotropin 2. Human chorionic somatomammotropin 3. Estrogen 4. Progesterone
KIDNEY	1. Erythropoietin 2. Renin 3. 1,25 dihydroxycholecalciferol

HORMONAL RECEPTORS

The hormone receptors are the large proteins present in the target cells. Each receptor is specific for one single hormone. That is each receptor can combine with only one hormone.