Adolescence begins in biology and ends in society. The definitions we accept to describe the onset of adolescence revolve around puberty, biological changes of the body. Therefore I consider adolescence to begin in biology. Adolescence ends in society. Entrance into adulthood marks the end of adolescence. The definitions of who is considered an adult are defined by society and therefore I contest that adolescence ends in society. The onset of adolescence is marked by a sudden increase in the production of many hormones in the body. The hypothalamus, the part of the brain that controls the pituitary, sends signals the increase hormone production. Growth hormone produced in the anterior pituitary is increased in production, targeting the soft tissue and bones making them grow rapidly. Gonadotropic or follicle stimulating hormone, also produced in the anterior pituitary, is increased and is responsible for the growth of hair on the body and face. The gonads, ovaries and testes, increase production of estrogen and testosterone respectively, which are responsible for the growth of secondary sex characteristics, such as breasts in females and masculine features in males. The production of these hormones causes many of the changes we characterize as the start of adolescence, to occur. The question remains, what causes the hypothalamus to signal these increases in the hormonal production? Much research has been done on this subject, however it has been inconclusive to an accepted reason. This is largely due to the fact that so far we cannot experiment physically on the brain to see what causes the signals to be sent from the hypothalamus to the pituitary. Most of the research is studies of different individuals and groups of similar individuals as to when they began adolescence and the genetic and environmental factors of the groups. Some research has shown the factors that control the onset, to be genetic. They argue that ti...
