A short review about sensitivity and reproduction

1. The functions of
sensitivity and
reproduction
CEIP Almirante Laulhe

2. What is sensitivity?
Through sensitivity, we respond to
changes in the external environment.
These changes are called stimuli.
For example, if the Sun is too bright, we
respond by shading our eyes. If we see
a large rock fallling towards us, we
respond by moving away.

3. How does
sensitivity
work?
3. Muscles receive
orders from the
brain and work with
bones to make the
body move.
1. Sense organs
capture information
from the
environment and
send it to the brain
through the nerves.
2. The nerves carry
information to the
brain. It decides
how we should
respond. The
nerves carry
responses to the
muscles.

4. THE NERVOUS SYSTEM
The nervous system carries out the function of sensitivity. It is in
charge of three important tasks:
It receives and interprets information from external and
internal environments.
It gives orders for our body to respond.
It controls and coordinates all organs and systems in our
body.

5. The central nervous
system
The
nervous
system is
made up of
two parts
The peripheral
nervous system
The peripheral nervous
systemis formed by only
one type of tissue,the
nervous tissue.

6. The central
nervous
system has
two parts.
Cerebrum
It controls
voluntary actions,
like running or
talking
Cerebellum
It controls
movement,
coordination and
balance.
Brainstem
It controls
internal organ
activities that we
don’t need to
think about, for
example, heart
rate and
breathing.
The brain is protected by the cranium and
has three parts:
The spinal cord is a long, thin bundle of nervous tissue. It
extends from the base of the brain to the bottom of the
spine, and connects the brain and the peripheral nervous
system. It produces involuntary responses, such as
moving our hand away from very hot objects.
balance: equilibrio
Heart rate: latido del corazón
breathing: respirar
bundle: haz, cordón
spine: espina dorsal
To move away: apartar

7. The
peripheral
nervous
sytems
connects...
the central nervous
system
sense
organs
the peripheral
nervous system
musclesinternal
organs

8. There are
two types
of nerves

9. Voluntary movements
Voluntary movements are actions
that we perform consciously (we
can start and stop them as we
wish).
Reflex movements
Reflex movements are automatic
movements that we make without thinking
about them. In many cases, they are
movements to protect us from being hurt
in dangerous situations.

10. Now it’s
your turn!
Choose only the words related to the
nervous system and write sentences
cerebrum eyes sensory nerves
brainstem bones muscles
spinal cord
Write two examples of each type of
movement.
Reflex movement
Voluntary movement

11. Reproduction

12. Primary sexual
characteristics
These are the
reproductive organs.
We are born with
these characteristics.
Sexual
characteristics
Secondary sexual
characteristics
These are other
physical differences
between men and
women.
Sexualcharacteristics
are the physical
differencesthat exist
betweenmen and women.
Sexual characteristics are classified into:

13. Puberty
▫ Puberty is the stage of life when
reproductive organs become functional.
▫ Sexual characteristics develop.
▫ Both boys and girls go through periods
of rapid growth.
▫ Boys develop a deeper voice.
▫ Girls develop breasts.
▫ Puberty may take place between the
ages of 10 and 14 in girls, and 12 and 16
in boys. These ages differ from person
to person.
▫ Puberty also causes emotional changes.
Our mood can change quickly, and we
become more sensitive and self-
conscious.
to develop: desarrollar
deeper: más grave
breasts: mamas
mood: humor, estado de ánimo
sensitive: sensible
self-conscious: cohibido, retraído

14. The female reproductive system
It consists of several organs.
The ovaries contain the female sex cells, known
as egg cells or ova.
The Fallopian tubes connect the ovaries to the
uterus.
The uterus is a hollow organ. The baby develops
there during pregnancy.
The vagina is a muscular tube between the
uterus and the outside of the body.
The vulva is the external part of the female
reproductive system. The vulva protect the
opening of the vagina.
ovariesFallopian tubes
uterus
vagina
vulva

15. The male reproductive system
It consists of the following organs:
The testes produce sperm, which contains the
male sex cells, known as sperm cells or
spermatozoa.
The sperm ducts are fine tubes thart connect the
testes to the urethra.
The prostate gland produces liquids which help to
transport espermatozoa and provide them
with nutrients. The mixture of these liquids and
sperm is called semen.
The urethra is a tube that transports semen to
the outside of the body. It also expels urine.
The penis is the organ that contains the urethra. urethra
sperm ducts prostate gland
penis testes

16. Female sex cells
♀ They are called ova.
♀ They are found in the ovaries
from birth.
♀ They are large, round cells
that can be seen with the
naked eye.
♀ They contain all the nutrients
required for the development
of an embryo.
♀ They mature during puberty.
Sex cells
Male sex cells
♂ They are called spermatozoa.
♂ They are produced in the
testes, starting at puberty.
♂ They are very small and
can only be seen under a
microscope.
♂ They have a small head
and a long tail which they
use to move.
● Images sizes are not proportioned.

17. Fertilization
Fertilization occurs when a sperm cell
joins with an egg cell.
During sexual intercourse, semen is
released into the woman’s vagina. The
spermatozoa travel through her uterus
into the Fallopian tubes. If an egg cell is
released from one of the ovaries,
fertilization can occur.
As a result of fertilization, a new cell,
called a zygote, is formed. The zygote
divides and form an embryo. The embryo
attaches itself to the wall of the uterus
and continues to grow.

18. Pregnancy
Pregnancy is the period from the moment of fertilization
until the birth of a baby. It lasts about nine months.
Once the embryo attaches itself to the uterus, two
main changes happen:
1.- The embryo is surrounded by a sac called
the amnion, which is filled with a liquid and protects
the embryo.
2.- A new organ called the placenta, form inside the
uterus. It provides nutrients and oxygen from
the mother to the embryo. The embryo and the
placenta are connected by the umbilical cord.
The initial embryo develops into a foetus. The foetus
continues to develop and grow until it is ready to be
born.
Development at
7-8 weeks from
conception

19. Now it’s
your turn!
Answer the following questions.
1. What are the names of the male and
female sex cells? Name the organs that
produce them.
2. Which organ expands during pregnancy?
3. Which organ produces liquids that mix with
sperm?
Classify the reproductive organs as male or
female.
prostate gland uterus
urethra ovaries
Fallopian tubes sperm ducts