Lesson 3 of 6 / Reproduction in humans
Trace the female reproductive system
Where are eggs released, fertilised and supported after implantation?
In this lesson: Identify the named female structures and distinguish their functions.
About 4 min
The key ideaOvaries release eggs; oviducts are the usual site of fertilisation; the uterus supports development after implantation.
Simplified front section. The ovaries lie near the open oviduct ends, not inside sealed tubes. The highlighted early embryo is enlarged.
Explanation
The ovaries contain developing eggs and produce oestrogen and progesterone. Ovulation releases an egg from an ovary. The nearby open end of an oviduct receives it; the ovary is not a sealed continuation of the tube.
The oviduct, also called the Fallopian tube, carries the egg towards the uterus. Fertilisation normally occurs in an oviduct if sperm reaches the egg. It does not normally wait until the egg reaches the uterine lining.
The uterus has a muscular wall and a lining that changes during the menstrual cycle. After fertilisation and early divisions, the developing ball of cells can implant in this lining, where further development is supported.
The cervix is the narrow neck at the lower end of the uterus, opening into the vagina. The vagina receives semen during sexual intercourse and forms part of the passage for birth and menstrual flow. The urinary urethra is a separate opening.
Step by step
- 1
Start at an ovary
Identify where the egg develops and is released.
- 2
Follow the oviduct
This is the usual fertilisation site and the route towards the uterus.
- 3
Separate later locations
Implantation occurs in uterine lining; the cervix connects uterus and vagina.
Worked example
Two different sites
Distinguish the usual site of fertilisation from the site of implantation in humans.
One way to explain it
Fertilisation usually occurs in an oviduct. Implantation occurs later, when the developing ball of cells embeds in the lining of the uterus.
Why this answer works
- The egg and early embryo move along a route.
- Fertilisation is nuclear fusion; implantation is embedding in tissue.
Is this true? "The ovary, oviduct and uterus are three names for the same place."
They have different roles: egg production and release, transport and usual fertilisation, then implantation and development.