Final answer:
The cervix is the passage between the vagina and the uterus, allowing for menstrual blood to exit and semen to enter. The vagina alternatively serves as a receptacle for the during intercourse, the pathway for childbirth, and the channel for menstrual flow.
Step-by-step explanation:
The structure described between the vagina and the uterus, providing pathways for menstrual blood to leave the body and for semen to enter it, is called the cervix. This part of the female reproductive system gradually dilates and thins during childbirth to allow the baby to pass from the uterus into the vaginal canal. The vagina is an elastic, muscular canal that serves various functions including being a receptacle for the during intercourse, the route for menstrual blood flow, and the vessel for the delivery of offspring.
During sexual intercourse, sperm are released into the vagina and travel through it to reach the uterus. The vagina's inner walls are lined with mucous membranes which contain transverse folds known as rugae, aiding its expansion during intercourse and childbirth. The vagina's muscular walls are lined with stratified squamous epithelial cells, which protect the underlying tissue and contribute to the vagina's elasticity and strength. Moreover, it is part of the female reproductive organ system that includes the uterus, an organ where a fetus develops, and the cervix, which connects the uterus and vagina.