Breast tissue changes primarily with pregnancy, as the body gears up to feed a newborn baby. (myorganicformula.com)
Because the microscope also acts as an incubator, the samples can survive for several days, allowing scientists to track how live cells or tissues change in real time. (gladstone.org)
Rising levels of hormones cause breast growth and other tissue changes, all in preparation for lactation. (babycenter.com)