BODY SYSTEMS

PRIMARY 5 & 6

MUSCULAR SYSTEM• We have more than 600 muscles. • Many of them are attached to our bones by

tendons. • When we tense a muscle, it gets shorter and

thicker.• Muscles need a good supply of blood and

oxygen to work well.• Before exercising dancers  warm up to

increase the blood flow to their muscles.• We use 17 muscles to smile.

DIGESTIVE SYSTEM• Food gives us energy.• The digestive system starts in the mouth. • When we swallow the food, it goes to the

stomach.• The stomach squahes the food and breaks it

down with strong juices.• Nutrients are absorbed into your blood.• The solid wastes are expelled by the anus.• There are 10.000 taste buds in our tongue.

CIRCULATORY SYSTEM

• The heart pumps blood around your body.• The arteries carry blood away from the heart and the

veins carry blood back to the heart .• The blood is made of a pale liquid called plasma.

White cells, red cells and platelets are elements floating in the plasma liquid.

• Red blood cells transport oxygen from your lungs to the rest of your body.

• White blood cells seek out and kill germs.• Platelets help our blood to clot and form a scab if we

bleed. • An adults heart pumps 15.000 litres of blood every

day.

SKELETAL SYSTEM• There are more than 206 bones in our body.• The skeleton supports our body.• The largest bone in our body is the femur.• The head bone is called skull and it protects

the brain.• The rib cage protects the lungs and heart.• Most of our bones are linked by joints.• When we break a bone new cells form at

each end of the broken bones, closing the gap between them.

RESPIRATORY SYSTEM

• We breathe because our body needs a gas called oxigen.

• Our lungs are like sponges full of tiny air tubes.

• The gas we inhale is called oxigen.

• The waste gas we expell out is called carbon dioxide.

• We take 23.000 breathes every day.

• Our nose can detect 10.000 different  smells.