Chapter 39 Notes The Endocrine System The endocrine system is made of glands that release their products into the bloodstream. There products broadcast messaged throughout the body. Hormones are chemicals that travel through the bloodstream and affect the activities of other cells. They bind to specific chemical receptors on those cells. Cells that have receptors for a particular hormone are called target cells. If a cell doesn't have a particular receptor or receptors that don't respond …showed first 75 words of 1975 total…

…showed last 75 words of 1975 total…of ovulation, the egg will pass through the uterus without implantation. The corpus luteum will begin to disintegrate. Old follicle breaks down, it releases less estrogen and progesterone. When the levels of estrogen fall below a certain point, the lining of the uterus begins to detach from the uterine wall. This tissue with blood and unfertilized egg discharge through vagina. Afterwards, the estrogen is low again and stimulated the hypothalamus to increase LH and FSH.