Suarez, A. At coitus, human sperm are deposited into the anterior vagina, where, to avoid vaginal acid and immune responses, they quickly contact cervical mucus and enter the cervix. Cervical mucus filters out sperm with poor morphology and motility and as such only a minority of ejaculated sperm actually enter the cervix. In the uterus, muscular contractions may enhance passage of sperm through the uterine cavity. A few thousand sperm swim through the uterotubal junctions to reach the Fallopian tubes uterine tubes, oviducts where sperm are stored in a reservoir, or at least maintained in a fertile state, by interacting with endosalpingeal oviductal epithelium. As the time of ovulation approaches, sperm become capacitated and hyperactivated, which enables them to proceed towards the tubal ampulla. Sperm may be guided to the oocyte by a combination of thermotaxis and chemotaxis.
Sperm Health: How Long Sperm Live & Details of the Journey
Fertility Basics | Complete Fertility
The male and female parts of the human reproductive system can bring together an egg and a sperm so that they join and begin the development of a new human being. The female system also protects and nourishes the developing foetus during the nine months of pregnancy. Sperm are made in the testes and mature in a coiled tube, the epididymis. At the end of sexual intercourse, they travel along the vas deferens and mix with fluids made by the prostate gland and seminal vesicle. The sperm then pass along the urethra to the tip of the penis and into the female vagina.
Achieving a healthy pregnancy is a complicated, multi-stage process involving two people. Every month, the female ovulates one mature egg from one of her ovaries. Here, it will begin to move slowly down the tube towards the womb uterus.
Fig 1. The journey begins with millions of sperm cells that are released into the female reproductive tract during intercourse. The sperm cells gain their full ability to swim when they are ejaculated into the reproductive tract [ 1 ],[ 2 ]. Upon ejaculation, the sperm cells are enclosed in a fluid called seminal plasma or semen, which is a mix of fluids from the testes, seminal vesicles, prostate, and the bulbourethral glands. The fluid contains elements which protect the sperm cells during their journey towards the egg.