1. Human Reproduction

2. The Male Reproductive System

3. 1. Penis - tube-like organ that hangs outside the body
- come in all sizes and shapes, determined by our genes
- during sexual intercourse, the spongy cells that surround the urethra fill with blood, and the penis becomes firm and erect

4. 2. Testicles - also known as testes - usually two, one hangs lower
- where sperm are made
- also produces testosterone (male sex hormone that regulates sperm production)

5. 3. Scrotum - bag of skin that holds testicles
- keeps them at right temperature to make sperm, slightly cooler than body’s temperature
- with age, gets bigger and baggier and turns a darker colour

6. 4. Epididymis - attached to testicles, inside scrotum
- stores the large numbers of sperm until they are
ejaculated out through the penis during sexual
intercourse.

7. 5. Urethra
- the tube through which urine and semen leaves the boy’s body (only 1 is released at a time)
the prostate gland enlarges to block off any urine from the bladder during sexual intercourse

8. 6. Vas Deferens
- transports sperm from the testes to urethra

9. Sperm flow out of the body through this pathway: Testicles Epididymis Vas Deferens Urethra

10. Spermatozoa Spermatozoa, also known as sperm, is the male
gamete (sex cell).
Sperm look like tadpoles
They are very small (the head is 5 µm by 3 µm, and the tail is 50 µm long)
Very fragile… needs to be kept at a good temperature, must stay hydrated and cannot be exposed to a very acidic environment
After puberty you make 200, ,000 sperm cells a day for the rest of your life
For reproduction to happen, the sperm needs reach
an egg and fertilize it.

11. Semen When sperm is released from the body, it is mixed with semen.
Semen is a fluid. It has 2 major functions:
- to protect the sperm from dehydration and the acidic environment of the female vagina
- allows the sperm to swim more easily
Semen is produced by 3 glands found in the male reproductive system:
Seminal Vesicles
Prostate Gland
Cowper’s Gland

12. The Female Reproductive System

14. Internal Anatomy: 1. Vagina - passageway joining outside and uterus
- an elastic & muscular organ that expands during birth to allow for the passage of the baby
- place where the penis is inserted during sexual intercourse

15. 2. Cervix - the opening between the vagina and the uterus
- sperm enters this opening during sex
- makes mucus to keep sperm alive
- during pregnancy, a mucous plug forms across the cervix separating the uterus from the outside to prevent infection of the unborn baby
- when giving birth, the cervix dilates (expands) to allow the baby to pass through

16. 3. Uterus - also known as the womb
- strong muscular and elastic organ where an unborn baby develops
normally the size of a pear, grows to the size of a watermelon when pregnant
- after an egg is released from the ovary, a blood-filled lining develops on the walls of the uterus in preparation for the unborn baby
if no fertilization of the egg occurs, then this lining passes out through the vagina over several days as ‘periods’ or menstruation
if there is fertilization, it is where the developing baby, called a fetus, grows and is fed

17. 4. Fallopian Tubes - narrow tubes between the uterus and the ovary
- place where conception or fertilization of an egg by a sperm occurs

18. 5. Ovaries - there are 2 ovaries (1 at the end of each Fallopian Tube)
- it is the gland that makes egg cells (ova) and female sex hormones (estrogen & progesterone)

19. Eggs exit the body through this pathway: Ovary Fallopian Tube Uterus Cervix Vagina

20. Ovum Ovum, also known as egg, is the female gamete (sex cell).
Girls are born with hundreds of thousands of tiny ova.
These egg cells are only half formed (immature)
at puberty, hormones tell the ovaries it is time to start releasing eggs
usually only one egg at a time matures (develops) and is released from an ovary
eggs stop being released once menopause hits (at approx. 45 to 55 years old)

21. Fertilization
For the ovum to be fertilized, a sperm must enter it while in the fallopian tubes.
During sexual intercourse,
millions of sperm are released
and all compete to get to the
potential ova first.