The secretion of human growth hormones (HGH) is regulated at the genome level by genetic and epigenetic factors (environment and diet among others). And the expression of the gene of this hormone differs from one individual to another, so the quantity produced differs between individuals, which explains why we observe individuals of different sizes in a population.
Growth hormone acts by interaction with cellular receptors, it affects carbohydrate, lipid and protein metabolism.
A key component of growth is the growth hormone releasing factor or the growth regulating factor (GH-RF or GRF). This chemical messenger is produced in a part of the brain called the hypothalamus. GH-RF allows the pituitary gland (the "master gland" involved in the growth process) to secrete growth hormone, the main hormone responsible for a person's growth.
GH is not only involved in growth phenomena, it also plays a role in the fine regulation of reproductive phenomena in both male and female mammals.
