Here are some quick tips on how to distinguish classic crystal from plain glass. 1  Hold up a glass to the light. 2  If the glass acts as a prism and you see a rainbow you are holding crystal. 3  If not, it is just plain glass. 4  When struck, crystal produces a musical ring. 5  Glass does not.
Hormonal control of menstrual cycle. The ovarian hormones circulate in the blood and are excreted in modified forms in the urine. Estimation of the urinary output by chemical methods gives an indication of the blood levels and of the total production of these substances.
These hormones help control the production of estrogen and progesterone. For most women, the average menstrual cycle lasts 28 days and goes through three major phases: the menstrual phase, the proliferate phase, and the secretory phase. What is the proliferative phase? The proliferative, or follicular, phase of the menstrual cycle is the part of the process in which the follicles inside the ovaries begin to develop and mature in order to prepare the body for ovulation.