menstrual cycle phase http://purl.obolibrary.org/obo/GO_0022601 https://www.wikidata.org/wiki/Q14908045 The progression of physiological phases, occurring in the endometrium during the menstrual cycle that recur at regular intervals during the reproductive years. The menstrual cycle is an ovulation cycle where the endometrium is shed if pregnancy does not occur. menstrual cycle phases biological phase menstrual cycle