Question
Trace the path of a sperm cell from where it is produced in the testes to the point of fertilisation. Name all the ducts and glands it passes through or receives secretions from, and state the contribution of each accessory gland.
Solution — Step by Step
Sperm are produced by spermatogenesis inside the seminiferous tubules of the testes. The testes sit outside the body cavity in the scrotum because sperm production needs a temperature 2–3°C below core body temperature.
From the seminiferous tubules, immature sperm move into the epididymis — a coiled tube sitting on top of each testis. This is where sperm mature and gain motility. They are stored here until ejaculation.
During ejaculation, muscular contractions push sperm through the vas deferens (also called ductus deferens). This duct loops up and over the urinary bladder before descending toward the urethra. It is the vas deferens that is cut in a vasectomy.
As sperm travel through the vas deferens toward the urethra, three glands add secretions to form semen:
- Seminal vesicles — contribute ~60% of semen volume. Their secretion is rich in fructose (energy source for sperm), prostaglandins, and proteins. The vas deferens joins the duct of the seminal vesicle to form the ejaculatory duct.
- Prostate gland — adds a milky, slightly alkaline fluid that neutralises the acidity of vaginal secretions, protecting sperm.
- Bulbourethral glands (Cowper’s glands) — produce a clear, lubricating fluid that also neutralises any residual urine acidity in the urethra before ejaculation.
The urethra is the final common pathway for both urine and semen (though not simultaneously). Sperm exit the body through the penis during ejaculation. After deposition in the vagina, sperm travel through the cervix → uterus → fallopian tube (uterine tube), where fertilisation occurs — specifically in the ampullary region of the fallopian tube.
Seminiferous tubules → Epididymis → Vas deferens → Ejaculatory duct → Urethra → Outside
Accessory glands add secretions: Seminal vesicles + Prostate + Bulbourethral glands = Semen
Fertilisation site: Ampullary region of the fallopian tube (oviduct)
Why This Works
The male reproductive tract is designed to solve two problems: keep sperm alive and get them to the egg. Sperm are produced at low temperature (hence the scrotum), stored in the epididymis where they complete maturation, and then launched through a muscular ductal system.
The accessory glands are not decoration — they are functional necessities. Without the fructose from seminal vesicles, sperm starve. Without the alkaline secretions of the prostate and bulbourethral glands, vaginal acidity would destroy sperm before they reach the cervix. Semen is therefore a precisely buffered, nutrient-rich transport medium.
The path from testes to egg is surprisingly long — sperm travel through the male and female tracts together covering nearly 20 cm or more. Only a few hundred sperm out of millions actually reach the fallopian tube, and only one fertilises the egg.
Alternative Method: Remembering the Path With a Mnemonic
For NEET, you need the path memorised cold. Use this:
“Some Every Vaughan Uses Foul Perfume”
| Letter | Structure |
|---|---|
| Some | Seminiferous tubules |
| Every | Epididymis |
| Vaughan | Vas deferens |
| Uses | Urethra |
| Foul | Fallopian tube |
| Perfume | (site of fertilisation) |
Add the three glands separately: “SBP” — Seminal vesicles, Bulbourethral, Prostate.
Common Mistake
Many students write that the urethra is part of the reproductive tract only. The urethra is shared between the urinary and reproductive systems in males — it carries both urine and semen (at different times, controlled by the internal urethral sphincter). In NEET 2023, a question specifically tested whether students knew this dual function. Writing “urethra carries only semen” will cost you marks.
The sequence of accessory gland secretions matters for CBSE long-answer questions: seminal vesicles first (at the ejaculatory duct level), then prostate (at the base of the bladder), then bulbourethral glands (just before the urethra). If a question asks “name the glands in order,” go distal to proximal — seminal vesicles → prostate → bulbourethral.