Neuroendocrine cells of the hypothalamus release into the bloodstream.

Neuroendocrine cells of the hypothalamus release releasing hormones into the bloodstream.
Releasing or hypothalamic hormones have a stimulatory or inhibitory effect on the release of the pituary hormones. The main hormones are:
·     Gonadotropin-releasing hormone (GnRH) stimulates the pituitary to release gonadotropin.
·     Thyrotropin-releasing hormone (TRH) stimulates the pituitary to release thyrotropin.
·     Growth hormone–releasing hormone (GHRH) stimulates the pituitary to release somatotropin.
·     Corticotropin-releasing hormone (CRH) stimulates the pituitary to release corticotropin.
·     Somatostatin which inhibit the release of somatotropin from pituitary and inhibits the release of some gastrointestinal hormones.

Humans can affect weathering and erosion in several ways.  humans cause  increases in acid rain and pollution, which increase the amount of  weathering  agents in the air and water, and then on land.for an easy answer: 1) acid rain2) pollution