Reproductive System
The only organs built for someone elseSystema genitale
Gonads that make gametes and hormones, ducts that carry them, and the glands and outlets that serve the journey — one plan, expressed two ways.
- Primary role
- Makes gametes and the sex hormones
- Scale
- Two gonads, roughly 30 cm of duct on each side
- Every day
- About 100 million sperm made daily, against one egg a month
Organs in this atlas 2
How it works as a whole
Every other system keeps its owner alive; this one is the only one a person can live an entire healthy life without using, and the only one that exists for a body that does not yet exist. It is built from a single embryonic plan. The same ridge of tissue becomes an ovary or a testis, the same tubercle becomes a clitoris or a glans, and the two duct systems that run beside the early kidney — one paramesonephric, one mesonephric — are both present in every embryo before one is kept and the other regresses. What follows from that shared origin is the whole logic of the system: a gonad that does two jobs at once, making gametes and making the hormones that run the rest of the body's cycle; a duct that both transports and matures; and accessory glands that add most of the volume of what is finally delivered.
Other key structures
- GonadsOvary and testis — the only organs that make gametes, and endocrine glands in the same breath
- Genital ductsUterine tube, uterus and vagina on one plan; epididymis, ductus deferens and urethra on the other
- Accessory glandsProstate, seminal vesicles and bulbourethral glands — most of the ejaculate is theirs, not the testis's
- External genitaliaVulva and penis, both grown from the same embryonic tubercle, folds and swellings
Connected systems
- Endocrine SystemThe gonads are endocrine organs taking orders from the pituitary — and the feedback they send back is what closes the loop
- Urinary SystemThe two systems share an origin and, in the male, an outlet: the urethra carries both, and the prostate wraps the point where they meet
- Cardiovascular SystemThe testicular and ovarian arteries come straight off the aorta, because the gonads began high on the posterior wall and dragged their blood supply down with them
Common conditions
- Infertility
- Endometriosis
- Polycystic ovary syndrome
- Benign prostatic hyperplasia
- Sexually transmitted infection
- Testicular torsion
The through-lineNothing here runs itself. The hypothalamus pulses GnRH, the pituitary answers with FSH and LH, and the gonad replies with oestradiol, progesterone or testosterone — a loop that sets puberty, the menstrual cycle, sperm production and, by feedback, its own restraint.
Did you knowThe ovary is fullest before birth: about seven million eggs at mid-gestation, one to two million at birth, and a few hundred ever ovulated.
The path through this system
0 of 19 steps done — read it, walk it in 3D, then be asked about it.
Start: Female genital tract: the lesson
ReadFemale genital tract: the lessonStructure and story of the female genital tract, layer by layer.
3 min
ReadMale genital tract: the lessonStructure and story of the male genital tract, layer by layer.
3 min
Guided walk-throughGuided dissection: female genital tractWalk the female genital tract structure by structure, then cut inward layer by layer.
6 min
Guided walk-throughGuided dissection: male genital tractWalk the male genital tract structure by structure, then cut inward layer by layer.
6 min
Memo cardsFemale genital tract memo cardsTurn the cards on the female genital tract — structures, layers, key facts — and grade yourself.
4 min
Multiple choiceFemale genital tract quizA multiple-choice round on the female genital tract, reshuffled every time.
4 min
Memo cardsMale genital tract memo cardsTurn the cards on the male genital tract — structures, layers, key facts — and grade yourself.
4 min
Multiple choiceMale genital tract quizA multiple-choice round on the male genital tract, reshuffled every time.
4 min
Click on the 3D modelFind the female genital tract structuresClick the named structures directly on the live 3D female genital tract.
5 minClick on the 3D modelFind the male genital tract structuresClick the named structures directly on the live 3D male genital tract.
5 minLabel the diagramLabelled diagram: Female genital tractThe female genital tract plate with its labels taken off: put each one back on its number, or draw it yourself first.
5 minLabel the diagramLabelled diagram: Male genital tractThe male genital tract plate with its labels taken off: put each one back on its number, or draw it yourself first.
5 min
Match layersMatch female genital tract layersPair each layer of the female genital tract, outside in, with what it does.
4 min
Match pairsMatch female genital tract structuresPair each structure in the female genital tract with its role.
4 minMatch layersMatch male genital tract layersPair each layer of the male genital tract, outside in, with what it does.
4 minMatch pairsMatch male genital tract structuresPair each structure in the male genital tract with its role.
4 min
Multiple choiceReproductive System quizA quiz pulling from every organ in the reproductive system.
4 minReadFemale genital tract in the clinicWhere the female genital tract shows up in the clinic, and what goes wrong.
3 min
ReadMale genital tract in the clinicWhere the male genital tract shows up in the clinic, and what goes wrong.
3 min