the part of the brain that regulates the production of the hormone melatonin is called
Melatonin Melatonin, also known as N-acetyl-5-methoxy tryptamine,[1] is a hormone that is produced by the pineal gland in animals and regulates sleep and wakefulness.[2] Melatonin is also produced in plants where it functions as a first line of defense against oxidative stress.[3]
Neuroscience of sleep In 1993, a different model called the opponent process model[92] was proposed. This model explained that these two processes opposed each other to produce sleep, as against Borbely's model. According to this model, the SCN, which is involved in the circadian rhythm, enhances wakefulness and opposes the homeostatic rhythm. In opposition is the homeostatic rhythm, regulated via a complex multisynaptic pathway in the hypothalamus that acts like a switch and shuts off the arousal system. Both effects together produce a see-saw like effect of sleep and wakefulness.[74] More recently, it has been proposed that both models have some validity to them, while new theories hold that inhibition of NREM sleep by REM could also play a role.[93] In any case, the two process mechanism adds flexibility to the simple circadian rhythm and could have evolved as an adaptive measure.
Stomach In classical anatomy, the human stomach is divided into four sections, beginning at the gastric cardia,[6] each of which has different cells and functions.
Hypothalamic–pituitary–gonadal axis In males, the production of GnRH, LH, and FSH are similar, but the effects of these hormones are different.[8] FSH stimulates sustentacular cells to release androgen-binding protein, which promotes testosterone binding. LH binds to the interstitial cells, causing them to secrete testosterone. Testosterone is required for normal spermatogenesis and inhibits the hypothalamus. Inhibin is produced by the spermatogenic cells, which, also through inactivating activin, inhibits the hypothalamus. After puberty these hormones levels remain relatively constant.