A reaction that classically occurs in this tissue to produce “monstrous cells” was historically misclassified as cancer until Peruvian histologist Javier Arias Stella identified it as benign. Cells from this tissue can seed mesothelial infoldings called Allen-Masters windows. Damage to this tissue’s decidua basalis (15[1])can generate scar tissue that forms adhesions in Asherman syndrome. A condition named for (15[1])this tissue produces (*) “chocolate (10[1])cysts,” as well as nodules (10[1])whose implantation in the pouch of Douglas and posterior fornix can cause (-5[1])dyspareunia. (-5[1])This tissue layer is supported by arteries that elongate during the proliferative phase and spiralize during the secretory phase. (10[1])Cancer of this tissue layer may manifest as a thickened “stripe” on ultrasound and cause abnormal bleeding in menopausal women. For 10 points, the withdrawal of progesterone causes what (-5[1])layer of tissue (10[1])lining the uterus to shed during menstruation? ■END■ (10[1]0[2])