What is the main function of the endometrium?

The primary role of the endometrium, which is the inner lining of the uterus, is to provide a suitable site for the implantation of the embryo. After fertilization, the embryo travels down the fallopian tube and into the uterus, where it must attach itself to the endometrial lining to establish a pregnancy.

The endometrium undergoes significant changes throughout the menstrual cycle, thickening in preparation for a potential implantation following ovulation. If implantation occurs, the endometrium continues to develop, providing the necessary support and nourishment to the growing embryo in its early stages. If implantation does not happen, the endometrial lining will shed during menstruation.

In other contexts, functions like the production of reproductive hormones or providing protective barriers during development are carried out by different tissues and structures in the reproductive system. For example, while the endometrium can respond to hormones, it does not primarily produce them; that function is more characteristic of the ovaries.