An excisional biopsy is the same procedure. The nodes act as filters, collecting bacteria or cancer cells that may travel through the lymph system. Measurements of the reaction are converted by a computer to cross-sectional images in which the internal body structure is clearly shown. Frequently, mammograms can show lesions in the breast too small or too deep to be felt in a manual examination. This hormone is needed to mature the egg and prepare the uterus for a possible pregnancy.
Menstruation occurs after the secretion of progesterone stops.