Blood and the circulatory
system
Be careful with your health
Observing human blood and blood
vessels
Human blood
appears to be a red liquid to the naked eye, but under a microscope we can see
that it contains four distinct elements: plasma, red blood cells, white blood
cells and platelets.
We have learning also what are
the differences between arteries and veins based on the observations under the
optical microscope and the main characteristics of the capillaries in
organs like the lungs or kidneys.
