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Blood is made up of plasma, red blood cells, platelets and white blood cells.Wellcome Images

Let’s Talk Science and the Royal Society of Canada have partnered to provide Globe and Mail readers with relevant coverage about issues that affect us all – from education to the impact of leading-edge scientific discoveries. Let’s Talk Science offers a number of fun activities to get youth engaged in STEM.

Make a model of blood and learn about the function of each of the parts that makes up blood.

What You Need

· Clear cup or container

· Water (enough to fill half of the container)

· Yellow food colouring (you may also want to use an apron to avoid staining your clothes)

· Kidney beans (dry, enough to fill the container)

· Rice (dry)

· 1 White lima bean (Dry)

What to Do

1. Create plasma: Fill a clear cup/container half-full of water. Add a few drops of yellow food colouring to make it look more like plasma.

2. Add red blood cells: Add red kidney beans until the cup/container is almost full. Leave a bit of room at the top.

3. Add platelets: Add a dash of rice to the cup/container.

4. Add the white blood cell: Add 1 white lima bean to the cup/container.

This is what your blood looks like!

What’s happening?

The average human adult has 5L of blood in their body. Blood is made up of plasma, red blood cells, platelets and white blood cells. Blood is carried in several different types of blood vessels: capillaries, venules, veins, arterioles and arteries. Blood vessels carrying blood out of the heart are called arteries; blood vessels carrying blood to the heart are called veins.

Plasma makes up 54% of blood. It is a yellow liquid that carries nutrients, hormones, proteins, and waste, as well as blood cells. Plasma is about 90% water.

Red blood cells make up 45% of blood. They are doughnut-shaped disks the size of a pinhead. They contain hemoglobin, which picks up and transports oxygen and carbon dioxide. Hemoglobin is what gives red blood cells their red colour.

Platelets are small cells that help blood coagulate (clump together, like when a cut turns to a scab). They are smaller than red blood cells and make up less than 1% of blood.

White blood cells help the body fight infection. There are two major types of white blood cells: lymphocytes and monocytes. Lymphocytes are made in lymph tissue and they make antibodies to attack foreign substances (the lymph system is an independent network that hooks into the circulatory system - it has its own capillaries). Monocytes are made in the bone marrow and they swallow up (engulf) foreign bodies.

Why does it matter?

The Canadian Blood Services collects approximately 810,000 units of blood every year. Blood donation depends on a thorough knowledge of blood components and blood typing.

Blood donations can be saved and used as whole blood products or each unit of blood can be separated into different components in order to help as many different people as possible. Whole blood can be processed and separated into plasma, red blood cells, platelets and a variety of special factors.

Investigate further

· Some blood diseases are directly the result of /or result in changes to the composition of blood. Investigate some of these diseases (anemia, lymphocytopenia, thrombocytopenia, Sickle cell anemia, etc.) and recreate the “blood” of someone with any of these conditions. Compare to the normal “blood.”

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