Doctors use an important blood test called a complete blood count, or CBC for short, to measure the number of each blood cell in your blood sample. If the CBC shows a low number of red blood cells, white blood cells, or platelets, your doctor may look at the cells under a microscope.
In a typical menstrual cycle, estrogen made by the maturing ovarian follicle causes the glands to grow and the endometrium to thicken (partly through an increased blood supply).This thickening of the uterine lining is called the proliferative phase of the menstrual cycle.n a typical menstrual cycle, estrogen made by the maturing ovarian follicle causes the glands to grow and the endometrium to thicken (partly through an increased blood supply).
During the menstrual CYCLE (not the menstrual period), the lining of the uterus, the endometrium, grows blood vessels and blood flows though the vessels.The endometrium and the associated blood vessels and blood is what is shed during the menstrual period. The endometrium also acts like a foreign object to the uterus.Should the egg be fertilized and implant, then the endometrium cannot be shed as if it were, the egg would be flushed out, too.est Answer: Interestingly, it is not the presence of a hormone that causes the endometrium (uterine lining that grows the blood vessels) to be shed, but it is the LACK of a hormone, progesterone, that causes the event.