Human Reproductive Systems

Section 1 of 6The male reproductive system

Part	Function
Testis	Makes sperm (the male gametes) and the hormone testosterone
Scrotum	A sac of skin holding the testes outside the body so they stay slightly cooler than body temperature, which suits sperm production
Sperm duct	Carries sperm from the testis towards the urethra, where glands add fluids to make semen
Urethra	Tube through the penis that carries semen, or urine at other times; a ring of muscle prevents the two mixing
Penis	Passes urine out of the body and places semen inside the vagina during intercourse

Section 2 of 6The female reproductive system

Part	Function
Ovary	Holds egg cells (ova) and releases a mature egg each cycle; also makes oestrogen and progesterone
Oviduct	Carries the egg towards the uterus; lined with cilia that sweep it along; the site of fertilisation
Uterus	Muscular organ with a soft lining in which a fertilised egg implants and the foetus develops
Cervix	Ring of muscle at the base of the uterus that holds the foetus in place during pregnancy
Vagina	Muscular tube that receives the penis and sperm and forms part of the birth canal

Section 3 of 6Path taken by sperm and egg

1Sperm production

• Sperm production Sperm form in the testes and move into the sperm ducts.

2Semen

• Semen Glands add fluids that nourish and carry the sperm. The mixture, semen, leaves through the urethra.

3Entry to the female

• Entry to the female Semen is released in the vagina.
  • Sperm swim through the cervix and uterus into the oviducts.

4Meeting the egg

• Meeting the egg If an egg released from the ovary is in the oviduct, fertilisation can occur there.

Section 4 of 6Adaptations worth remembering

Cooler testes

• Cooler testes Sperm production works best a little below body temperature, which is why the scrotum hangs outside the body.

Ciliated oviduct

• Ciliated oviduct Cilia and muscle movements push the egg slowly along the tube.

Muscular uterus wall

• Muscular uterus wall The thick muscle can stretch as the foetus grows and contract strongly during birth.

Section 5 of 6Key terms

Term	Meaning
Testis	Male organ that makes sperm and testosterone.
Ovary	Female organ that stores and releases eggs and makes hormones.
Oviduct	The tube between ovary and uterus where fertilisation takes place.
Uterus	The womb, where the foetus develops.
Semen	Sperm mixed with fluid from glands.
Implantation	Attachment of the embryo to the uterus lining.

Section 6 of 6Exam technique

1

Saying fertilisation takes place in the uterus. It happens in the oviduct.

2

Mixing up the sperm duct and the urethra. The sperm duct carries only sperm; the urethra carries semen or urine.

3

Writing that the ovary makes eggs every month from nothing; the ovary holds immature eggs that mature and are released one at a time.

4

Forgetting that the testes also make the hormone testosterone, not only sperm.