Final answer:
Estrogen is the hormone responsible for regenerating the uterine lining that is shed during menstruation. It stimulates the growth of the endometrial lining during the follicular phase of the menstrual cycle.
Step-by-step explanation:
The hormone that helps regenerate the uterine lining that was shed during menstruation is estrogen. During the follicular phase of the menstrual cycle, estrogen is secreted by the maturing ovarian follicles, which leads to the growth or proliferation of the endometrial lining of the uterus. This prepares the endometrium for a potential implantation. Estrogen is significant for its role in endometrial regrowth as well as ovulation and calcium absorption, in addition to contributing to secondary sexual characteristics in females. While progesterone is essential during the luteal phase for maintaining a thick endometrium, should fertilization not occur, its levels drop, leading to the shedding of the endometrial lining. However, it is estrogen that primarily drives the regrowth of the endometrium following menstruation.