Natural Science 3º Grade

Unit 2The vital functions of humans beings

interactionreproduction

Nutrition is the process of taking food.Nutrition turns food into nutrients.

Food contains small substances called nutrients.

When we eat, we take nutrients into our body.

Our body transforms nutrients into materials.These materials give us energy.These materials help us grow.

interactionInteraction describes the relationship that we havewith the world around us.

When we feel cold, we cover ourselves up to get warm.

We receive information from outside our bodies from our senses.

Reproduction

We reproduce to make sure that more humans like us continue to live after we die.

Reproduction is the process of makingand giving birth to a baby.

Nutrition: The digestive system. Digestion is the process of breaking down food into nutrients.Digestion takes place inside the digestive system.

Respiratory systemThere are two important processes involved in respiration.

The process of inhaling and exhaling.The process of exchanging two gases: oxygen and carbon dioxide.

Inhalation exhalation

We breathe in air.

Our lungs get bigger.

We take oxygen.

We breathe air out.

Our lungs get smaller.

We push out the carbon dioxide

Nasal passage.Air passes through it.

Vocal cords produce the soundwe use when we speak.

Alveoli are air sacks wheregas exchange takes place.

Lungs are two spongy organsthat are protected by the rib cage.

The pharynx allows the airto flow from the mouth andnose into the lungs.

The windpipe is a wide tube whereair flow to and from the lungs.It leads to the bronchi.

Bronchi are two major air tubesin the lungs. They connect themto the windpipe and lead to thealveoli.

Respiratory system

The circulatory system

The circulatory system includes the heart and the blood vessels.

heart

The heart is responsible forpumping blood around the body.

veinsarteries

Blood vessels Blood vessels carry blood cells around the body.

There are three types of vessels

Capillaries arteries veins

Artery capillary veins

Vocabulary:Blood vessels : vasossanguíneosCapillaries: CapilaresArteries: arteriasVeins: venas.

Excretory system

KidneysKidneys clean the blood.Kidneys take out harmful waste.

UretersUrine travels fromthe kidneys throughthe ureters to the bladder.

bladder urethraBladder is where urineis stored.

Urine leaves the bodythrough a tube calledurethra.

The excretory system is responsible for removing unwanted substances from the body.

urine

Vocabulary:Ureters: uréteres Bladder: vejiga de la orinaKidneys: riñonesUrethra: uretra

interaction Through interaction,we use our senses to capture information from our environment.

Our sense of taste allows us to identify different flavours.

Our sense of smell allows us to smell odours.

Through the sense of hearing we understand sounds and what they mean.

Through our sense of sightwe understand the colour, shapeand size of an object.

Through the sense of touchwe know the temperatureof an object and what it feelslike.

The information we receive through our sense is called stimulus ans it travels to our brain through our nerves.

Vocabulary:Environment: medio ambiente.Allow: permitirFlavours: saboresOdours:olores Understand: entenderMean: significarStimulus: estímuloBrain: celebro.

WHITE

YELLOW

ORANGE

RED

PINK

PURPLE

GREEN

LIGHT BLUE

BLUE

BROWN

BLACK

GREY

BIG MEDIUM SMALL

circle square triangle

rectangle oval

sweet saltybittersour

flavours

The nervous system.

This is a complex system that sends information through our nerves to different parts of the body.

The brain is the centralpart of the nervous system.• Our brain organices information.• Our brain makes decisions.

The musculoskeletal system

Bones and muscles belong to the musculoskeletal system.

muscle

bonesThe musculoskeletal system receives messagesthat tell our body to move.

There are :

Voluntary movements Involuntary movements.

We move our body without thinking.These are reflex actions.

These are actions we thinkabout and choose to do.

Reproductive systemWe perform the reproduction function through the female and male reproductive system.

Female reproductive system Male reproductive system

The ovaries produce eggs.The are connected to theuterus.

The uterus is where the baby develops until itis born.

The vagina is a tubethat leads from theuterus to the outsideof the body.

The vulva is the external part of the female reproductive system.

Female reproductive system

Male reproductive system.

The penis is an external organ

The testes are two ovalshape external organs.The testes produce sperm.

The urethra is a tube insidethe penis.The urethra carries urine fromthe bladder.The urethra carries semen.Semen is a mixture of fluids and sperm.

Pregnancy and delivery

During pregnancy a babyforms and grows insideits mother.

The stage of reproductionprocess last nine months.

The baby begins lifeinside the uterus asa foetus.

The baby grows inside the amniotic sac.The amniotic sac contains a liquid that protectsthe baby.

The baby is joined to its mother by an umbilical cord.The baby gets food an oxygen throughthe umbilical cord.After birth the umbilical cord is cut.

The phase of the reproduction process when the mother´s body is ready to give birth is called the delivery.

Amniotic sac