Final answer:
Sperm that move through the female reproductive tract are nourished by 'tubular fluid' which helps in their survival and capacitation process for successful fertilization of the oocyte.
Step-by-step explanation:
Sperm that move through the female reproductive tract are nourished by tubular fluid which contains nutrients that keep them viable during their passage towards the oocyte (egg).
Sperm transition through various environments after they are deposited in the female reproductive system. Upon ejaculation, sperm mixed with seminal fluid from the male reproductive glands creates semen, which enters the female reproductive tract. The environment within the female reproductive system poses several challenges for sperm. For instance, they must survive the acidity of the vagina and navigate through the mucus in the cervix. However, once in the fallopian tubes, sperm are assisted by the tubular fluid which nourishes and enables them for the process of capacitation.
Capacitation is essential as it increases the motility of sperm and prepares them for successful fertilization by altering their membrane properties. Without the vital nutrients in the tubular fluid and the capacitation process, sperm would not be able to reach or penetrate the oocyte. Thus, the journey of sperm is a meticulously coordinated event that requires both internal changes induced by the female reproductive system fluids and the inherent resilience of the sperm itself.