Process of Growth
Growth in stature, determined by its various factors, results from the lengthening of bones via cellular divisions chiefly regulated by somatotropin (human growth hormone (hGH)) secreted by the anterior pituitary gland. Somatotropin also stimulates the release of another growth inducing hormone Insulin-like growth factor 1 (IGF-1) mainly by the liver. Both hormones operate on most tissues of the body, have many other functions, and continue to be secreted throughout life; with peak levels coinciding with peak growth velocity, and gradually subsiding with age after adolescence. The bulk of secretion occurs in bursts (especially for adolescents) with the largest during sleep.
The majority of linear growth occurs as growth of cartilage at the epiphysis (ends) of the long bones which gradually ossify to form hard bone. The legs compose approximately half of adult human height, and leg length is a somewhat sexually dimorphic trait. Some of this growth occurs after the growth spurt of the long bones has ceased or slowed. The majority of growth during growth spurts is of the long bones. Additionally, the variation in height between populations and across time is largely due to changes in leg length. The remainder of height consists of the cranium. Height is sexually dimorphic and statistically it is more or less normally distributed, but with heavy tails.
Read more about this topic: Human Height
Famous quotes containing the words process of, process and/or growth:
“A process of genocide is being carried out before the eyes of the world.”
—Pope John Paul II (b. 1920)
“The process of education in the oldest profession in the world is like any other educational process, in that it requires time and effort and patience; it can only be acquired by taking one step at a time, though the steps become accelerated after the first few.”
—Madeleine [Blair], U.S. prostitute and “madam.” Madeleine, ch. 4 (1919)
“Unlimited economic growth has the marvelous quality of stilling discontent while maintaining privilege, a fact that has not gone unnoticed among liberal economists.”
—Noam Chomsky (b. 1928)