1. Reproductive Organs, gametes and Fertilisation
Testes and Ovaries

2. What you should know
The structure and function of reproductive organs and gametes and their role in fertilisation.
Gamete production in the testes. The roles of seminiferous tubules, interstitial cells, testosterone, prostate gland and seminal vesicles.
Gamete production in the ovaries to include maturation of ova and the development of a follicle. Site of fertilisation in the oviduct and zygote formation.

3. Reproductive Organs and Gametes
Prior Knowledge
Reproductive organs produce gametes
Male gamete- sperm
Female gamete- egg/ova
Male reproductive organ- testes
Female reproductive organ-ovary

4. Production of Gametes
A germ line is the sex cells (eggs and sperm) that are used by sexually reproducing organisms to pass on genes from generation to generation.
Gametes are produced by germline cells

5. MALE REPRODUCTIVE SYSTEM
BLADDER
URETER
PUBIC BONE
SEMINAL VESICLE
PROSTATE GLAND
RECTUM
URETHRA
ERECTILE TISSUE
VAS DEFERENS/ sperm duct
PENIS
EPIDIDYMIS
SCROTUM
TESTIS

6. The testes are the site of sperm (spermatozoa) production The testes are also the site of manufacture of the male sex hormone testosterone Sperm are formed from germline cells in tiny tubes called Seminiferous Tubules Seminiferous tubules unite to form coiled tubes that connect to the Sperm Duct – free swimming sperm leave the testes in the sperm duct

7. TESTES
SEMINIFEROUS TUBULE
INTERSTITIAL CELLS

8. Interstitial Cells
Between the seminiferous tubules are cells called the Interstitial Cells These cells produce the hormone Testosterone Testosterone passes directly into the blood stream Fertilisation depends on the motility of the sperm - motility requires a fluid medium and a source of energy

9. TESTES Seminiferous tubules – produce sperm
Interstitial cells– secrete testosterone
Interstitial cells

10. Seminal Vesicles and Prostate

11. The seminal vesicles and the prostate gland are known as accessory glands
Semen consists of 10% sperm and 90% fluid and as sperm pass down the ducts from testis to penis, (accessory) glands add various secretions
The prostate gland and seminal vesicles secrete fluids that maintain the mobility and viability of the sperm. This fluid is called semen

12. Seminal Vesicles
Seminal Vesicles – secrete a liquid rich in fructose to provide energy for sperm motility the liquid contains hormone-like compounds that stimulate contraction of the female reproductive tract these contractions help the sperm to reach the oviduct (where fertilisation takes place) quicker than ‘swimming’ alone

13. Prostate Gland
The prostate gland secretes lubricating liquid containing enzymes
These enzymes maintain the fluid at optimum viscosity for sperm motility
Just before ovulation the cells lining the female cervix secrete a watery mucus
this watery mucus is easily penetrated by sperm

14. FEMALE REPRODUCTIVE SYSTEM
OVIDUCT
ENDOMETRIUM
OVARY
UTERUS
CERVIX
VAGINA

15. Ovaries
Eggs or Ova are formed from germline cells in the female ovaries The ovaries contain immature eggs at various stages of development Ovulation is when a mature ovum is released, from the ovary, into the oviduct Fertilisation takes place in the oviduct if sperm are present - fertilised egg or zygote develops into an embryo

16. GRAAFIAN FOLLICLE

17. Human Ovulation

22. Follicle
Each ovum (egg) is surrounded by a structure called a follicle which protects the ovum
The follicle secretes the female sex hormone called oestrogen
After ovulation it secretes the sex hormone progesterone, as well as oestrogen

23. Try these questions . . . . Where in a testis are sperm produced?
Which hormone is produced by interstitial cells?
Which accessory glands secrete a liquid rich in hormone-like chemicals?
Describe the contribution to fertilisation made by these chemicals
Name the structure that surrounds the egg in an ovary

24. Answers . . . . Seminiferous tubules Testosterone Seminal vesicles
They stimulate the female reproductive tract to contract, creating movements that help the sperm reach the oviduct
follicle