1. Human Sexual Reproduction
Let’s Talk about Sex
Human Sexual Reproduction

2. What’s Happening?

3. What will I look like when I grow up?
That depends mostly on your heredity, the genes you got when an egg cell and a sperm cell from your birth parents came together to make the cells that developed into you.
Genes mostly determine how tall you will grow, the colour of your hair, the size and shape of your penis or breasts and your overall body shape.
Other things that affect our body are the foods we eat, how active we are and how much sleep we get.

4. What is Puberty?
It is the time when our bodies change toward an adult body.
Start to develop new feelings and interests
Start to make sperm cells
Or start to make egg cells

5. What is Puberty? The cells necessary to make a new human
egg + sperm = baby

6. What changes happen to boys?
Grow taller and heavier
Bones grow bigger and heavier
Nose and jaw get bigger and face gets longer
Get more muscles
Hair and skin can become oily and you may get pimples
Body sweats more
Hair grows on the face, under the armpits, around the genitals (pubic hair).

7. What changes happen to boys?
May get more hair on arms, legs and chest.
Voice gets deeper
Penis and testicles grow
Scrotum changes
May have mood swings, sexual thoughts and feelings
Breasts may grow

8. What changes happen to girls?
Get taller and heavier
Bones grow bigger and heavier
Hips get wider and more curvy
Face changes shape
Voice gets a little deeper

9. What changes happen to girls?
Hair grows under the armpits, around the genitals (pubic hair)
Hair on arms and legs grows darker
Breasts and nipples get larger
Body sweats more
Internal and external sex organs grow
May have mood swings, sexual thoughts and feelings

10. What causes these changes?
It is the sex hormones that make the changes that cause children’s bodies grow into adult bodies.
Both boys and girls make the same sex hormones. The main ones are testosterone and estrogen
Boys make lots of testosterone, not so much estrogen
Girls make lots of estrogen, not so much testosterone

11. What Is The Function Of The Pituitary Gland?
The pituitary gland secretes (creates and releases) hormones.
For males, these hormones are testosterone.
For females, these hormones
are progesterone & estrogen.

12. The hormones produced by the pituitary gland travel in the bloodstream until they reach the testicles or ovaries to send the signals to produce spermatozoa or ova.

13. Watch this…

14. Sexual Reproductive Organs

15. What are the male sex organs?
These parts are also called the reproductive organs and genitals
The parts are:
 Urethra
Penis
Testicles or Testes
Scrotum

16. What are the sex organs? Urethra Penis Testicles or testes Scrotum
the tube through which urine and semen leaves the boy’s body
Penis
tube-like organ that hangs outside the body
come in all sizes and shapes, determined by our genes
Testicles or testes
usually two, one hangs lower
Sometimes called balls or nuts
Where sperm are made
Scrotum
bag of skin that holds testicles
keeps them at right temperature to make sperm, slightly cooler than body’s temperature
gets bigger and baggier and turns a darker colour

17. What happens on the inside?
Hormones from the pituitary make the testicles grow and they start making more testosterone and producing sperm 
After puberty you make 200, ,000 sperm cells a day for the rest of your life
Sperm build up in tubes around the testicles
They travel along some tubes and mix with fluids from glands

18. What are the female sex organs?
These parts are also called the reproductive organs and genitals.
The parts on the outside are:
Vulva
The area of soft skin between a female’s legs.
Clitoris
Small organ made of nerves and tissue.
At the top where the lips join.
Only the tip is on the outside, the rest is hidden inside.
Sensitive to touch. Can feel tingly and pleasurable.  
Labia
Soft folds of skin that cover the inner parts
Grow darker and bigger at puberty.

19. What are the sex organs? Urethra Not a sex organ.
Tiny opening that urine comes out from the bladder.
Vaginal opening
Entrance to the vagina.
Hymen
Thin piece of skin that may cover part of the opening to the vagina.
Often small or missing.
Anus
Between the two cheeks of the buttocks.
It is where bowel movements come out.

20. The parts on the inside are:
Uterus
Sometimes called the womb.
Muscular organ about the size of a pear.
Where developing baby, called a fetus, grows and is fed.
Where the period comes from.
Vagina
Warm, soft, moist passageway joining outside and uterus.

21. The parts on the inside are:
Fallopian tubes
Narrow tubes between the uterus and the ovary.
Ovaries
Glands that make egg cells and female sex hormones.
Cervix
The lower part of the uterus.
Makes mucus to keep sperm alive.
Has opening where sperm enter uterus and where the baby comes out of the uterus.

22. So what are periods and why do they happen?
Girls are born with hundreds of thousands of tiny eggs, called ova – one is called an ovum.
These egg cells are only half formed.
At puberty, hormones tell the ovaries it is time to start releasing ova.
Usually one egg at a time matures (develops) and is released from an ovary.

23. So what are periods and why do they happen?
At the same time, the uterus starts to grow a thick lining on the inside wall.
The lining has lots of tiny blood vessels.
The lining is there to protect and feed an egg that has combined with a sperm to form a fertilized egg.

24. So what are periods and why do they happen?
If an egg does not meet a sperm, the lining is not needed.
It breaks up.
Mixed with some blood it comes out the uterus into the vagina and then out the vaginal opening.
This is called menstruation but lots of females just call it their period.
If a woman is not pregnant then her ovary will release another egg, the lining build up and, if the egg is not fertilized, she has another period.
This is called the menstrual cycle.

25. Possibility of fertilization; Estrogen#1
One ovum matures;
Possibility of fertilization; Estrogen

26. Uterus lining begins to thicken;#2
Uterus lining begins to thicken;
Ovulation

27. #3
Possibility of fertilization;Uterus lining continues to thicken; Progesterone

28. Unfertilized ovum dies#4

29. Shedding of endometrium & unfertilized ovum (PERIOD)#5
Shedding of endometrium
& unfertilized ovum (PERIOD)

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