Chapter 6 introduced an essential part of the cell: the. plasma membrane. Thanks to the selective permeability of. phospholipid bilayers and the activity of membrane trans-. port proteins, this structure creates an internal environment. that is different from conditions outside the cell. Our task.
When calcium levels decrease, this stimulates the parathyroid gland to release parathyroid hormone. Parathyroid hormone encourages the normal process of bone breakdown (essential for maintenance and growth of the bone). This process of bone breakdown releases calcium into the bloodstream.
1 Adrenocorticotropic hormone, which stimulates the adrenal glands to secrete steroid hormones, principally cortisol. 2  Growth hormone, which regulates growth, metabolism and body composition. 3  Luteinising hormone and follicle stimulating hormone, also known as gonadotrophins.rolactin, which stimulates milk production Thyroid stimulating hormone, which stimulates the thyroid gland to secrete thyroid hormones. There are also some hormones that are produced by the hypothalamus and then stored in the posterior pituitary gland prior to being released into the bloodstream.