Key area 1 : Gamete production and fertilisation

How and where are gametes produced in males ?

Gametes are produced from germline cells. The testes is site of production for the male sex cells.

Site of sperm production

The testes are the site of sperm production

Site of manufacturing of the male sex hormone (testosterone)

Testes, specifically in the interstitial cells between the seminiferous tubules.

The hormone passes directly into the blood stream

Trajectory of sperm

• Sperm is produced in the testes, more specifically the seminiferous tubules

• The seminiferous tubules unite to form coiled tubules connecting to the sperm duct

• Sperm leaves the testes in the sperm duct

Prostate gland

• Fertilization depends on the mobility of sperm

• Mobility requires a fluid medium and a source of energy

• The prostate gland secretes this needed lubricant in liquid that contains the enzyme that maintains the optimum viscosity for sperm mobility

Conditions for fertilization in female genitalia

• Just before ovulation the cells lining the female cervix secretes a watery liquid

• This watery mucus is easily penetrable by sperm

Seminal Vesicles

• They secrete a liquid rich in fructose to provide energy for sperm mobility

• This liquid contains hormone like compounds that simulate contraction of the female reproductive track

• These contractions help the sperm to reach the oviduct

Semen

• Semen is the collective name given to the milky liquid release by males

• Sperm from seminal vesicles + fluid from the prostate gland

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

• After ovulation it secretes the sex hormone progesterone, as well as oestrogen

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

Fertilisation

• Mature ova are realised into the oviduct

• If sperm are present fertilisation may take place in the oviduct

• The fertilised egg is known as a zygote and develops into an embryo