Name the functions of the following:
$(a)$ Corpus luteum
$(b)$ Endometrium
$(c)$ Acrosome
$(d)$ Sperm tail
$(e)$ Fimbriae

(N/A) Corpus luteum: It is formed from the ruptured Graafian follicle. It secretes progesterone hormone during the luteal phase of the menstrual cycle. High levels of progesterone inhibit the secretion of $FSH$ and $LH$,thereby preventing further ovulation. It also maintains the endometrium for embryo implantation.
$(b)$ Endometrium: It is the innermost glandular lining of the uterus. It undergoes cyclic changes during the menstrual cycle to prepare itself for the implantation of the embryo.
$(c)$ Acrosome: It is a cap-like structure present in the anterior part of the sperm head. It contains hydrolytic enzymes (like hyaluronidase) that help the sperm penetrate the egg membrane during fertilization.
$(d)$ Sperm tail: It is the longest part of the sperm that facilitates motility,allowing the sperm to move through the female reproductive tract.
$(e)$ Fimbriae: These are finger-like projections at the ovarian end of the fallopian tube. They help in the collection of the ovum released from the ovary after ovulation.