The Journey of the Winning Sperm

Step 1

Puberty starts in a male between the ages of 12 and 13 sperm starts being produced. 1,000 sperm roll off the production line with every heartbeat. 

Step 2

Sperm spends two weeks passing through a long winding tube called the epididymis.

Step 3

Leaves the epididymis and remain alive, healthy and motionless for several weeks in the man’s body. If ejaculation does not happen often, then older degenerating sperm can damage newer sperm leaving the epididymis.

Step 4

Ejaculation – sperm being stored at the end of the epididymis are propelled by muscular contractions through a tube called the vas deferens and then into the tube passing down the penis (the urethra)

Step 5

Sperm must escape quickly from the vagina to the cervix to survive. 1 in 100 of the sperm ejaculated into the vagina will ever make it into the relative safety of the cervix

Step 6

Sperm will turn left or right, only one of her ovaries will release an egg in any given month, sperm must swim in the right direction.

Step 7

Travel through the Fallopian tube which acts as a valve only letting certain sperm inside. The selection process is based on two things, if sperm swim too erratically then they are unable to get inside, two sperm with certain molecules on their surface can’t get into the Fallopian tube.

Step 8

Once inside the Fallopian tubes, sperm stick to the inner walls.

Step 9

Sperm get the signal the egg is ready. Sperm detached themselves from the walls.

Step 10

Sperm swim down the Fallopian tube in the direction of the ovary in order to find an egg.

Step 11

Sperm must swim through a cloud of cells called the cumulus to make contact with the egg surface.

Step 12

Sperm must now get inside the egg once it reaches the egg surface using its hyperactivated tail beat.

Step 13

Once reaching the surface of the egg a bag of enzymes on top of the sperm head bursts. This enzyme dissolves the outer membrane of the egg and in combination with powerful tail thrusts the sperm penetrates the egg.

Step 14

Once the sperm is inside an immediate chemical reaction occurs hardening the egg membrane to stop any other sperm from entering.

Step 15

For the next few hours the sperm tail is detached and the chromosomes inside the sperm head separate to line up with the egg chromosomes. This starts the process of forming a new individual.