Final answer:
The birth passage is also known as the birth canal, starting from the uterus and ending with the vagina, through which the baby passes during childbirth followed by the delivery of the placenta.
Step-by-step explanation:
The birth passage is the maternal birth canal which begins in the uterus and ends in the vagina. During the process of childbirth, the baby travels through this passage starting from the thinned and dilated cervix, moving out of the uterus, and eventually being expelled through the vagina. Following the birth of the baby, the placenta and associated fetal membranes are delivered during the final stage of labor, concluding the childbirth process.