Growth

Growth Together with the nervous system, the endocrine system regulates and integrates the body’s metabolic activities. The endocrine system meets the nervous system at the hypothalamus. The hypothalamus controls the function of the endocrine organs by neural and hormonal pathways. In response to the hypothalamus, the anterior pituitary secretes prolactin, stimulating milk production and human Growth Hormone (hGH) which affects most body tissues. hGH stimulates growth by increasing protein synthesis, fat mobilization and by decreasing carbohydrate utilization. Hyposecretion of hGH results in dwarfism; hypersecretion causes gigantism and acromegaly in adults. IGF-1 or Sometomedin-C is a peptide highly dependent on growth hormone and has a potent growth promoting activity. The IGF-1 is transported in serum by several IGF-binding proteins. Measurements of IGF-1 are a useful adjunct to assessment of growth hormone secretion. A normal plasma or serum IGF-1 concentration is strong evidence against Growth Hormone (GH) deficiency, with the exception of GH deficient children with craniopharyngiomas and adults who have prolactin secreting tumors accompanied by GH deficiency and prolactin excess.