Eyeball DissectionOn Friday Mr Gardiner and I delivered a Medical BTEC unit with a mathematics focus to his Sixth Form group. The objective of the session was to calculate the volume and density of sheep eyeballs through using the formulae V=4/3πr3 and p=v/r, however we decided to take an unusual practical approach.
The session was broken down into three sections. We started by removing as much external tissue from the sheep eyes as possible. We then recorded the mass of the eyes and dropped them into Archimedes displacement cans filled with water. By collecting the water displaced, we were able to work out the volume of each eye and using the formula, density = mass / volume, the density of each eye.
To maximize the opportunity of having the sheep eyes available we carried out a full dissection, identifying every structure and discussing its function. Particularly noticeable was the tapetum lucidum (Latin for ‘bright tapestry’) a beautiful multi-coloured tissue that sits behind the retina. It is extremely reflective and improves night vision. This structure is absent in humans, however it is highly developed in many other mammals and is why cats eyes seem to ‘glow’ in the dark!
We then took measurements of the dissected eyes and used the above formulae to calculate volume and density. When we compared our theoretical results with our practical results they were amazingly similar.
Feedback from the students was very positive. They said they found the session engaging, informative and fun!
Mrs Heard (Senior Technician)
and Mr Gardiner (CL for Science)