Bits of Blood!

Curriculum links:

• Biology – Living things and human life

Learning objectives:

1. Understand what blood is, and what jobs it does
2. Become familiar with the different parts of blood and make models of them.

Materials:

• Bowl
• Red and blue food colouring
• Cornflour
• Syrup
• Whisk
• Measuring spoons
• Evil Laugh and Spoons!

Safety:

• Be careful with the mixture as the food colouring can stain hands and also skin. It’s not dangerous but can take a while to wash off!
• Wear an apron or old clothes.

Instructions:

This recipe should make enough to use on your face (about 8ml).

• Get one teaspoon of cornflour (other flour should work too) and drop it into the bowl.
• Then add half a teaspoon of red food colouring
• Next add one full tablespoon of syrup. I use maple syrup and that worked fine. Often you’ll see recipes with corn syrup but that is not readily available in Irish shops.
• Next add a couple of drops of blue food colouring to darken your blood
• Finally grab the whisk and stir like crazy making sure to add a maniacal laugh or two. Play around with the mixture until you are happy with the colour and consistency of the fake blood. Great thing about this is that you can eat it! Bad thing is that it will stain. Great thing – it’ll scare anyone who sees it!

How it works:

So what is blood?

Blood is like your internal delivery system. Its primary role is to take oxygen that you’ve inhaled through your lungs and with the help of the heart, bring it all over your body.

Adults have about 5 litres of blood whereas children have about 3 litres. Blood has 4 main parts that we want to talk about: Red blood cells, white blood cells, platelets and plasma.

Red Blood Cells.

In a single drop of blood there are about 5,000,000 red blood cells. So the same amount of people in Ireland roughly! Red blood cells carry oxygen around the body. They are the reason that blood is red because there are more red cells than any of the other types of blood cell. Blood is always red but it is a different shade of red depending on whether it is carrying oxygen or not. Red blood cells are shaped like bowls with a really thick rim.

White Blood Cells.

There are about 12,000 white blood cells in a single drop of blood. Their job is to be part of our immune system and help fight off infections. They are the biggest blood cell but also the fewest. There are a few different types of white cell but they all help fight infection. They come in different shapes and some look like furry golf balls.

Platelets.

Platelets are not actually cells but parts of cells. There are about 200,000 in a drop of blood and their job is to stick together against one another when there is a break in a blood vessel like a cut. They help the blood clotting process and help form scabs so that your skin can heal after its been hurt. They have long stretchy almost limbs and are small.

Plasma

Plasma is the yellowy clear liquid that all of the blood cells float in and makes up about half of the volume of the blood that you have! (You can make a model of the blood using mala!)