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

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

SOME METHODS OF BIRTH CONTROLMETHOD HOW IT WORKS ADVANTAGES AND

DISADVANTAGES

ABSTINENCE (Natural)

Careful record of menstrual cycle over several months, so that the woman can predict roughly when an egg is likely to be present in her oviducts. Sexual intercourse must be avoided around this time.

It is never possible to be 100% certain when ovulation is going to happen.Used by many people who do not want to use another contraceptive method.

CONTRACEPTIVE PILL (chemical)

Contains oestrogen and progesterone, which are made when the woman is pregnant and stop egg production. One pill is taken every day

Very effective method, as long as the pills are taken at the right time. However, unpleasant side-effects may be experienced. Women must have regular check-ups with the doctor.

CONDOM ( mechanical)

It traps semen, as it is released stopping it from entering the vagina.

Safe method if used correctly.Helps to prevent the transfer of infection, such as gonorrhoea and HIV.

DIAPHRAGM (mechanical)

Circular sheet of rubber placed over the cervix, at the top of the vagina. Sperm deposited in the vagina cannot get past the diaphragm into the uterus.

Effective method if used and fitted correctly. Fitting must be done by a doctor, but after that a woman can put her own diaphragm in and take it out as needed.

STERILISATION (surgical)

Man: sperm ducts are cut or tied.Woman: the oviducts are cut or tied.

Extremely sure with no side- effects. However, the tubes cannot be re-openedIt is not a method for young people.

SEXUAL TRANSMISSABLE DISEASES

• GONORRHOEA

• AIDS

GONORRHOEA

Microorganism Symptoms/signs How to prenvent infection

treatment

Bacteria(Neisseria)- Only survives in moist places, such as the tissues lining the tubes in the reproductive systems.

-MAN: It reproduces inside the urethra. Unpleasant discharge and pain when urinating.

- WOMEN: it reproduces mostly in the cervix. Discharge and no pain. They are anaware that they have the infection

-Having only one sexual partner.-- Condom-- tracing, warning and treating all possible sexual contacts of a person who is diagnosed with gonorrhoea to make sure that it does not spread any furthur.

Antibiotics(penicillin)

Always succesful.

AIDS: acquired immune deficiency syndromeMicroorganism Methods of

transmissionHow it affects the immune system

Ways in which can be prevented

HIV: human immunodeficiency virus

-Direct contact of your body fluids with those of someone with the viru:.-Through sexual intercourse: can live in the fluid inside the vagina, rectum and urethra.-- Through blood contact: a) blood transfusionsb) Sharing hypodermic needlesc) People who have to deal with accidents: paramedics, police

-HIV infects lymphocytes, in particular T cells. They are unable to fight against other pathogens effectively.-They become vulnerable to other infections such as pneumonia, they may develop cancer and brain cells are also damaged.- They die of a collection of several illnesses.

-Having one sexual partner.- Using condoms lowers the chances of the virus passing from one person to another.- Blood used in transfusions must be screened for HIV before it is used.- Use of sterile needles.- Paramedics and policemen: use of protective clothes.