Year 12 Biology

Yesterday, our Year 12 Biology class conducted a dissection of a Rattus norvegicus (Rat). We had seven rats, bred at the universities of Otago and Canterbury , to dissect in groups of about three. We had to make a shallow incision down the abdomen of the specimen from the front legs to the back legs, from there we had to cut through the fat and muscle layers taking extra care not to cut the organs underneath. This created flaps of skin. Once opened we pinned the legs of the specimen to the mat so we could get a better view of its internal anatomy. 

The first thing we saw was its intestines, small and large. We had to take extra care to not damage these as they would create an awful smell. After this we cut and removed the rib cage, which was surprisingly easy because it was a small animal and it had very little and thin bones. After the removal of the rib cage we gained access to the animals heart and lungs. We removed these along with the liver, stomach and intestines and placed this to the side. 

This was an interesting task as it showed us how similar we are to this animal. Something interesting we found out was that our rat was a female, this was rare as most of the rats dissected are male. We got to look at the internal reproductive organs of a female rat, which are different to humans. The rat had uterine horns, which angle towards the animal's kidneys. These uterine horns are similar to ovaries in females. The reason we did this dissection is because in class we are doing an assessment on mammals digestive systems. 

Overall we found this dissection incredibly fascinating and the smell wasn’t that bad (but Mrs Wilson would disagree!). We would like to thank Mrs Wilson, Mrs Rangi, Mrs White (who was jumping up and down with excitement) and Cat.