the story so far…….. the first stage in reproduction.. sexual intercourse: copulation
TRANSCRIPT
The story so far……..
The first stage in reproduction..
• Sexual Intercourse:
• Copulation
Humans have specially designed reproductive organs for copulation.Male Reproductive System
Prostate Gland
Produces the fluid which nourishes the sperm and allows them to swim
Testes
Produces and stores the sperm
Sperm Duct
Carries the sperm from the testes to the penis
Penis
Is placed inside the vagina where it deposits sperm
Female Reproductive System
Vagina
Entry point of the penis during copulation.
Cervix
Connects the uterus to the vagina
Uterus
Develops a spongy lining for the embryo to implant
Ovary
Stores and releases egg cells
Oviduct
Where fertilisation takes place. Embryo moves down towards uterus.
Route to Fertilisation
Ovary
Oviduct Uterus
11.
1. Egg is released from the ovary and picked up by the oviduct.
2
2.Egg is moved along oviduct by hair like cilia.
4.
3.
3. Sperm is deposited in the vagina and swims towards the egg up the oviduct.
4. Sperm and egg meet and FERTILISATION takes place.
After Fertilisation
Ovary
Oviduct Uterus1. 1. Fertilisation produces a Zygote.
2. The zygote divides in half to form an embryo.
2
3, The embryo continues to divide until it forms a ball of identical cells.
3
4
4. The embryo implants itself in the wall of the uterus where it continues to develop.
Once the embryo has implanted itself within the uterus the ball of cells begins to specialise into different
types of cells.• The embryo must not only develop into a
baby but it must also provide a way of catering for the developing babys needs.
What are these needs?
Food ProtectionExcrete Waste Products
Oxygen
Food, Oxygen and Excretion of waste
Supplying food and oxygen and the excretion of waste is the responsibility of
the placenta.
The placenta is a link between the mother and the developing embryo
The placenta is formed from part of the embryonic ball of cells
Placenta
Placenta
Foetus
Umbilical Cord
The Placenta is formed around two weeks after the embryo has implanted in the uterus.
A closer look
• Although very close together the maternal and foetal bloodstream do not mix.
Mother
Foetus
Foetal blood supplyMaternal Blood
Supply
FoodOxygen CO2 Waste
The required substances are able to pass from the mothers blood supply to the foetus and vice versa by DIFFUSION
Umbilical chord
PROTECTION• The developing foetus is vulnerable and needs
protection• This is provided by a fluid called amnion which is
enclosed in the amniotic sac.• Amniocentesis is a test performed on the amnion
which can detect chromosomal defects.
Embryonic Development 1st Month
SIZE: 0.5 cm
Features Formed: spine, nervous system kidneys, intestines,
Additional Notes: Day 21 heart starts beating , legs,arms eyes and ears are noticeable
Foetal Development 2nd Month
Size:1 cm.
Features Formed: Arms legs, fingers and toes.
Additional Notes: Recognisable as a human so it is a foetus Responds to touch and can feel pain. Can hear the amniotic fluid rushing by.
Foetal Development 3rd Month
Size: 5cm
Features Formed: vocal chords and brain fully formed
Additional Notes:Foetus can squint swallow frown and make a fist. The mother may a kick as it moves around
Foetal Development 5th Month
Size:30 cm
Features Formed: completely developed. Eyebrows and eyelashes. Sex organs formedAdditional notes: recognise voices, can jump in surprise.
Foetal Development 7th Month
Size:40 cm
Features Formed: fully developed
Additional notes: Foetus spends most of its time sleeping. Over the next two months it will grow to 3x its length and develop fat.
Gestation Period
The gestation period is the time from the implantation of the egg to the birth of the baby.
In humans it is approximately 9 months
Have a guess how long the gestation period is for a cat??
• 6o days gestation
Guess how long the gestation period is for this mouse?
• 12 days!!!!
Guess how long the gestation period is for an elephant?
• An elephant has the longest gestation period of 18- 22 months
The final stage of reproduction is the birth of the new individual
The baby decides when it is time to arrive and sends a message to the
mother.The placenta detaches from the mother and the baby begins its journey down the cervix.
The mother will feel contractions as the baby moves, this is the first sign of labour.
The amniotic sac will then burst releasing the fluid this is known as your waters breaking.
The baby will continue to move down through the cervix and out of the vagina
You are about to see the most amazing video clip
Look away if your squeemish
Congratulations you have survived the journey of
reproduction from start to end.
Wasn’t it AMAZING