Week Three – Urinary System
Arrival craft: Paper urinary system from Scholastic model book.
Introduction: Last week we looked at the digestive system. Closely connected to that is the urinary system. Does anyone know what it does?
Our urinary system gets rid of extra water and various wastes that our bodies don’t need.
Our kidneys play a very important role in the urinary system. They filter waste out of our blood.
Do you know how filtration works?
Filtration is a way of separating mixtures.
Show the mixtures we made earlier (lego and sand, sand and rice, rice and pasta, sand and water), ask the children how they would separate them and get a volunteer to try: there are colanders, sieves and filter paper to use.
When we look at real kidneys, do you think they will have big holes like the colander in them?
The substances – like salts – which kidneys filter out of blood are much smaller than pasta, rice, or even sand. So the holes need to be small too.
Individual task: Make paper kidneys.
Break for drink and snack.
Gather Together: Does anyone know whereabouts on the body our kidneys are?
If nobody knows, encourage the children to look at the paper anatomy models we’re building.
I have an anatomy model that we can look at, can we name the digestive organs, and find the kidneys.
Ask volunteers to come up, name the digestive organs and remove them from the model, until we find the kidneys.
Before you cut into your kidney, try to find the tubes coming out of it. There should be three, what do you think they are for?
The renal artery (thicker than vein) carries blood to the kidneys; the renal vein carries blood back to the heart; the ureter carries urine to the bladder.
Kidneys are a distinctive shape, they look like kidney beans.
They have a very distinctive shape inside too, the middle is made of triangle shaped tissues – these are called ‘renal pyramids’.
After you cut your kidney in half.
Demonstrate with one of the kidneys.
You can try to find the renal pyramids.
How many pyramids does your kidney have? Can you see the stripes on your pyramids? Are they vertical – going towards the centre of the kidney – or horizontal? You could add these features to your paper kidneys,
Individual task: Dissect Kidneys. kidneydissection