That red liquid that flows through all the intricate veins in our bodies.
What is blood? Very young children know that blood is the red liquid that flows out from beneath their skin, if they get cut or scraped. However, the details of blood can be hard to explain to preschool-aged children. During the week of lessons on our hearts, I take the time to discuss the details of blood: what it is, why we have it, what it does, and what its made of.
Another reason to keep our bones strong and healthy.
In the previous lessons on our bodies, I taught all about our bones and bone marrow - the blood maker. When introducing the lesson on blood, I review the previous portion on bone marrow. Bone marrow makes our red blood cells, white blood cells and blood platelets. If we aren't keeping our bones healthy, they won't be able to make healthy blood to carry the oxygen, food and water to the rest of our body.
Each of the four components of blood have a picture card.
During the lesson on what makes up our blood, I place out a picture card for each component, as we talk about them individually. Cells and platelets have an additional character picture that I place next to the card, to help my students remember the job of the component. After the lesson, I attach the lesson cards and character pictures up on the whiteboard above the sensory table. At the end of the lesson, I also show a picture card with a copy of an actual microscopic image of a red blood cell, white blood cell and a blood platelet.
Red blood cells make up the largest part of blood and give our blood the red color. A red blood cell looks like a squished or flattened ball. Red blood cells carry oxygen from the lungs to every part of our body, from head to toe. Without oxygen, our body wouldn't be able to keep working or survive. The character picture is a red blood cell with scuba diving gear (carrying an oxygen tank through our bodies).
White blood cells are larger than red, and the amount that flows around in our bodies can change. I make sure to tell my students that white blood cells have two roles: a few serve and protect, keeping us safe from everyday germs; but if we get sick, our body makes a lot of white blood cell soldiers. Those white blood cell soldiers join those that fight off the everyday germs and storm through our body to fight off the enemy (a.k.a. sickness). There are two character pictures for white blood cells. The first cell has a sheriff badge and the second cell has an army helmet.
Blood platelets are much smaller than cells and have an irregular shape. Microscopic images of platelets show tentacle like arms, protruding from random locations around the cell. Platelets help the healing process of cuts and scrapes by sticking together, forming a clot (natures bandaid). The character picture for the platelet has a medical bag and stethoscope.
I have attached the PDF files for the cards and characters, as a freebie download, at the bottom of this blog post.
This is a hands-on sensory experience that solidifies the lesson to memory.
As followup to our mini lesson on what our blood is made of, I have a sensory table set up to continue with a hands-on experience that helps to solidify the lesson to memory. Since its one that involves waterbeads, I only keep this sensory table out for one week. Waterbeads can be kept relatively clean and germ free by having your scholars wash their hands thoroughly before discovering. I teach a specific routine at the beginning of the year, that my scholars follow no matter the sensory table set-up:
1. wash hands
2. put on a smock
4. clean up spills
5. wash hands
Before expanding the waterbeads, I add a tablespoon or more of white distilled vinegar (depending on the amount of waterbeads I choose to expand). Then, I add the directed amount of water. When the waterbeads have expanded to size, I immediately drain and rinse them. Distilled vinegar helps to ward off germs and mold.
As an extra preventative, I rinse the waterbeads at the end of each day. I've had waterbeads last several weeks using these prevention steps. However, I do notice that my students tend to be less careful or routine conscious, after a certain period of time, so I typically keep this type of sensory table out for only a week.
Hands-on visuals that resemble what has been taught,
can make a big impact on comprehension of the lesson.
The red blood cells are the waterbeads, the white blood cells are pingpong balls, the platelets are cut pieces of tan colored craft foam and the plasma is water. For fine motor tools I add bubble tongs and small rectangular plastic collection pails. The collection pails are labeled for collecting the three different cells.
The cards and character PDF files
can be downloaded by clicking the link below:
My Amazon Picks to complete the 'What Is Blood Made Of?' sensory table are: