Reproductive System

A sex cell is known as a gamete

• The male sex cell (or gamete) is called sperm; the female sex cell (or gamete) is called the egg

Fertilisation occurs when a sperm fuses with an egg

Fertilisation occurs in the fallopian tube

Part Function

Ovary To produce eggs

Fallopian tube To carry the egg towards the womb. Fertilisation occurs here.

Womb (uterus) To hold the baby during pregnancy

Cervix The entrance to the womb

Vagina To hold the penis during sexual intercourse.To allow childbirth

bladder

seminal vesicle

prostrate gland

testis

scrotum

penis

erectile tissue

sperm duct

urethra

Part Function

Testes To produce sperm

Scrotum To hold the testes outside body, which favours sperm production (temp = 2oC lower)

Sperm duct To carry sperm from the testes to the penis

Prostate gland To produce fluids which nourish the sperm(fluid + sperm = semen)

Penis To deliver sperm into the woman’s body

The menstrual cycle

• Menstruation is the shedding of the lining of the uterus

• The menstrual cycle lasts about 28 days and menstruation occurs at the start of the cycle

•

In Each Menstrual Cycle:Day 1 –5: The lining of the uterus breaks down and passes out of the body (a period occurs)

Day 6 – 13: A new lining forms in the uertus and a new egg develops in the ovary

Day 14:An egg is released from the ovary (ovulation)

Day 15 – 28:The lining of the uterus remains in place until the next menstrual cylce

Fertile Period

• These are the days on which pregnancy is most likely to occur.

• Typically this is from days 11 –16.

Ovulation

• The release of the egg from the ovary

Sexual intercourse occurs when the erect penis of the male is placed in the vagina of the female

• Fertilisation is the fusion between male and female gametes (sperm and egg) resulting in a zygote

• A zygote undergoes cell division and develops within the womb into a foetus

Implantation occurs when the dividing zygote attaches itself to the lining of the uterus.

Pregnancy: the foetus inside the womb

Implantation occurs when the dividing zygote (ball of cells) attaches itself to the lining of the uterus.

Human pregnancy usually lasts about 40 weeks After 8 weeks the embryo is recognisable as a

human and is the called a foetus. Placenta acts as a link between the mother’s

bloodstream and that of the developing embryo (it brings in nutrients and takes away waste).

Nutrients Waste

Oxygen Carbon Dioxide

Food Urea

Alcohol/Drugs Salts

Pregnancy

• This is the length of time the baby spends developing in the uterus.

During Pregnancy:

• The baby is surrounded by a membrane called amnion

• Amniotic fluid surrounds and protects the baby

• The umbilical cord connects the baby and placenta

• The placenta allows substances to be exchanged between the mother and the baby

The birth itself

1.Contractions begin (muscles in the uterus contract).

2.‘breaking of the waters’ (liquid, or amniotic fluid or fluid escapes).

3.Cervix dilates(widens).

4.The baby is pushed through the cervix (into the vagina)

Contraception

TWO TYPES

• CHEMICAL• PHYSICAL

Chemical Contraception

• Some pills prevents the embryo implanting in the uterus

Physical contraception• Avoiding intercourse at certain times• Using a condom, a cap or chemicals to kill sperm

Surgical Contraception

• • Surgery to close off the sperm ducts (Vasectomy) or fallopian tubes.