1. Unit 4 human
reproduction
María Boizas Crespo

2. Human reproduction
 Living things create other
living things in the process of
reproduction.
 Human beings reproduce
through sexual reproduction ,
bringing male and female sex
cells together.

3. Primary sexual
characteristis
 The reproductive systems are
the primary sexual
characteristics.We already
have them when we are born
and they are different for male
and female.

4. Secondary sexual
characteristics
 The external characteristics
wich differentiate men from
women are called secondary
sexual characteristics.
 During puberty,between the
ages of eleven and fifteen,the
reproductive system matures.

5. Changes during puberty
 Some changes are the same
for both sexes like:
 Growing taller.
 Hair growing in the armpit.
 Other changes are specific to
each sex:
 Girlsdevelop breasts and their
hips get wider.
 Boys get deeper voices.

6. The reproductive
cells:sperm
 Sperm are the male
reproductive cells.They have
a head and a long tail called a
flagellum.They are produced
in large numbers from the
time of puberty.

7. The reproductive cells:ova
 Ova are the female reproductive
cells.They do not move.from
puberty,an ovum matures every
month.

8. The female reproductive
system
 The female reproductive
system is made up of these
organs:
 The ovaries produce the ova.
 The uterus is where the baby
develops.
 The fallopian tubes conects the
ovaries to the uterus.
 The vagina conects the uterus
to the outside of the body.
 The vulva is the external part of
the female reproductive system.

10. The male reproductive system
 The male reproductive system is
made up of these organs:
 The testicles are outside the
body.They produce sperm.They are
covered by a bag of skin called
scrotum.
 The vas deferens take the sperm
from the testicles to the urethra.
 The urethra takes the sperm outside
the body.
 The seminal vesicles and prostate
produce seminal fluid and send it to
the urethra.
 The penis is outside the male
reproductive system.

12. Pregnancy (I)
 Pregnancy lasts about 9
months and ends in a birth.
 During the early stage
different structures are
created to protect the
embryo:
 The placenta takes nutrients
from the mothers blood to the
embryo.
 The umbilical cord connects the
placenta to the embryo.
 The amniotic sac protects the

13. Pregnancy (II)
 The baby develops step by
step:
 After 3 months: The embryo has
all its organs.It becomes a
foetus.
 After 5 months: The baby’s
body develops and it starts
moving and the mother feels it.
 After 5 months: The baby is
ready to be born and it weighs
around 3 kilos.

14. Labour
 The process of giving birth is
called labour.
 Labour takes place in three
phases:
 Dilation:rhytmic contractions
make the opening of the vagina
and vulva big enough for the
baby to come out.
 Expulsion:the baby is born and
the doctor cuts the umbilical
cord.
 After birth:the placenta comes
out of the mother’s body.

15. The end