HUMAN REPRODUCTION

Sexual reproduction is the processinvolving the fusion of haploid nuclei to form adiploid zygote and the production of genetically

dissimilar offspring

MALE REPRODUCTIVE SYSTEM

HORMONES: male

• Testosterone (testes)• Development of male sexual secondary

characteristics: - Penis and testes grow: produce sperm and

testosterone - Facial hair develops - Changes to larynx: deeper voice - Hair grows on chest and in armpits - Pubic hair develops

FEMALE REPRODUCTIVE SYSTEM

FEMALE REPRODUCTIVE SYSTEM

HORMONES: female

• Oestrogen and progesterone• Development of male sexual secondary characteristics: - Ovaries grow- eggs develop and female hormones are

released - Hair grows in armpits - Brests develop/increase in size - Hips broaden - Pubic hair grows - Vagina enlargens

Female hormones

OVARIES

MENSTRUAL CYCLE

Fertilisation: the joining of the nuclei of the male gamete (sperm) and the female gamete (egg)

Ovulation and implantation

PLACENTA

BIRTH

• It begins when the strong muscles in the wall of the uterus start to contract. This is called labour.

• The wall of the cervix, gradually becomes wide enough for the baby to be pushed through.

• The wall of the vagina can stretch to allow the baby to be pushed through.

Birth

Afterbirth The placenta falls away from the wall of the uterus, and passes out through the vagina.

ANTE-NATAL CARE• Diet plenty of calcium: why?• Diet plenty of extra iron: why?• Diet with extra carbohydrates: why?• Diet with extra protein: why?• Continue to take exercise• No smoking: why?• Not too much alcohol or drugs.• Avoid illnesses: rubella (deaf or other

disabilities)• AIDS: the virus HIV can cross the placenta

Breast feeding vs. Milk formula

Advantage of breast milk vs. Formula milk

• Free!• No need to use an equipment, which, unless clean it

´s easier for bacteria to get into the milk and make the baby ill.

• Contains antibodies from the mother, which helps the baby ti fight off infectious diseases.

• Close relationship to develop between mother and baby.

The composition changes as it grows so that´s exactly right for the different stages of development.

BIRTH CONTROL:methods

• NATURAL →abstinence

• CHEMICAL →contraceptive pill →spermicide• MECHANICAL →condom →diaphragm →IUD• SURGICAL → vasectomy → female sterilisation

References

• http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/S/Sexual_Reproduction.html

• http://www.biotopics.co.uk/human2/reprsy.html