Overview of Some Important Hormones of the Endocrine System

The endocrine system consists of several hormonal functions and activity, but an overview would be concentrated on the growth hormone, adrenorcoticotropic hormone, thyrotropin or thyroid-stimulating hormone and the Gonadotropic hormones. What are their functions and what peculiarities can we see from a person suffering from their respective disorders?

Growth hormone promotes growth of bone and soft tissues without affecting sexual development. Its direct effect on protein anabolism promotes cellular growth. It accelerates fat catabolism and utilization for energy, although it's exact effect on carbohydrate metabolism is not known, it tends to increase the blood glucose concentration a hyperglycemic response. The secretion of growth hormone is under the influence of somatotrpin-releasing factor (SRF) from the hypothalamus. Hyposecretion of growth hormone during the years of skeletal growth results in a condition called dwarfism. If it occurs after apiphyseal closure (during late adolescence) it cuases a rare condition known as simmonds' disease (pituitary cachexia). Hypersecretion during the years of active bone growth produces gigantism, whereas excess growth hormone during adult life results in acromgaly.

Criteria for diagnosis of GHD
• Height below 3rd percentile
• Prepubertal growth velocity less than 4cm per year
• Bone age below the chronological age
• Abnormal 24 hour GH secretory pattern
• Peak GH levels less than 10ng/ml during provocative stimulation tests
• Low IGF-1 and IGFBP-3 levels for age
• Resumption of growth following GH administration

Acromelagy main symptoms
• Weakness
• Enlargement of the distal parts of the body
• Thickening of facial features
• Widening of the fingers
• Hypogonadism
• Narrower field of vision
• Increase of the level of somatotropin hormone in the plasma
• Excessive hairiness

Adrenocorticotropic hormone
The main function of adrenocorticotrpic hormone is to control the adrenal gland's secretion of glucorcorticoids and, to a lesser extent, of androgen. The control of adrenocorticotropic hormone secretion is under the influence of the hypothalamic chemical conticortropin-releasing factor. Hyposecretion of hypersecretion of adrenorcorticortropic hormone results in clinical manifestations directly attributable to a lack of excess of hormones from the target gland, the adrenal cortex.

Adison disease
• Brown color of the kin
• Progressive fatigue
• Loss of weight
• Anorexia
• Loss of blood pressure
• Anemia

Thyrotropin or thyroid-stimulating hormone
As its name implies, thyroid-stimulating hormone promotes and maintains growth of the thyroid gland and stimulates its secretion of thyroid hormone (thyroxine and triiodothyroxine). The secretion of thyroid-stimulating hormone is controlled by thyrotropin-releasing factor (TRF) from the hypothalamus. Hyposecretion of hypersecreation of thyroid-stimulating hormone produces symptoms directly attributable to a lack or excess of thyroid hormone.

Gonadotropic hormones
The gonadotropic hormones follicle-stimualting hormone, luteinizing hormone, interstitial cell-stimualting hormone, and prolactin are responsible for the growth and maturation of the gonads at puberty and for the ongoing stimulation of germ cell production during adulthood.