A nice 2 minute introduction to an eye dissection
via MyScienceAcademy
Category: From snout to tail
Special specimen: what holds a pig up?
What holds a pig up? The internal skeletal system in the Kingdom Animalia, sub-Phylum Vertebrata, which includes mammals (pigs), fish, amphibians, reptiles and birds has many functions.
Cervical vertebra. Includes 7 cervical vertebra (atlas, 2-7), 4 thoracic vertebra and the first 4 sternal ribs. There are always 7 cervical vertebra in pigs (and humans). In Figure 1 you can see the spinal cord and vertebral disks too!
Thoracic vertebra. The specimen shown in Figure 2 includes 9 thoracic vertebra, ribs, vertebral disks and spinal cord. The number of thoracic vertebra varies between pig breeds from 13-17. Where do the ribs attach to the vertebra? Find out this one time only, $6.00.
Figure 3 shows the shoulder joint. It includes the scapula, humerus and fused radius and ulna. One only in stock at the moment, $6.50. If you need more than one Miss Vivi can order these for you.
Loin chop (Figure 4). NOT FOR SALE – it’s for Mr Vivi’s dinner. But you can see the elongated transverse process on the lumbar vertebra (the bone pointing to 8 o’clock) that supports the strong muscle (yummy meaty bit) that in turn supports the viscera in the abdominal cavity.
Pig tail (Figure 5). Tail bones are called caudal bones. The number of caudal bones varies between species of pig between 20 and 23. How many does this one have? Find out for $5.00
See how all the bits fit together on this model in Figure 6. http://www.fallingpixel.com/pig-skeleton-3d-model/39932
If you have the need for bone specimens for a class in science or physical education, get in contact with Miss Vivi as she can source a wide range of specimens as a special order.
Top tip: spinal cord and brain dissection in piglets
Teaching science can be a tough gig. Most of the time teachers feel that they are time poor and content rich. Fitting everything required by the curriculum into a term can feel like herding cats into a bag.
Teachers know that kids want to explore science more than be taught it, but often it’s just not possible to let them take as much time as they need to really get as much learning out of an experiment as they would like.
That’s why I’m over the moon when I hear that a class has had the time to really get more bang for their buck out of one of our specimens. These photos have been sent by a labbie who bought them for a teacher wanting to teach about the brain and spinal cord. We decided that piglets would be the best option to teach this and the kids were enjoying it so much that when they were finished looking at that they flipped them over and got into the abdominal organs as well. Truly a case of learning about everything but the squeal.
The labbie says:
“They are an excellent class. It was great to see how involved they were during the prac. They really enjoyed it!
Because this dissection took place over just one period, I was requested to prepare the piglets prior to the prac, exposing the brain and the spine. … We couldn’t get hold of a Dremmel at the time so, used a hack saw to cut a cross in the skull then, cut the hole out with a pair of kitchen scissors. He also suggested that a Dremmel would be perfect for this job. It’s been put on our list for purchases prior to the budget rollover.
I then prepared the others which made it quicker and easier for the students to then get to where the brain stem and the spinal cord meet since that was their main aim for the prac.
After that the piglets were dissected even further as you saw, to locate and expose all other organs in the stomach cavity etc
All of our Science staff were extremely impressed on the quality the specimens you sent.”
Before we sent the piglets we had a bit of discussion by email about the best course of action for this prac. I still don’t have a Dremel and haven’t had a go at it, but this is what we suggested:
We believe that the best tool for opening the skull will be a small circular saw called a Dremel available at hardware stores. I was speaking to a very experienced biology teacher … that runs an extensive comparative anatomy program in his Yr 12 classes who agrees that they are the tool for the job. I am going to buy one and have a go myself. Do be careful because the skull will be slippery. You will use the Dremel to score the skull and then need a chisel and hammer to ease the skull open. There are some very good videos on YouTube that will show you what to do.
To expose the spinal cord at the back of the neck you will need to cut into the skin on either side of the spine at the base of the skull and lever the section away from the body and towards the tail. You will also be able to view the spinal cord and spinal nerves by opening the abdomen of the piglet and removing the organs to expose the spine. You will be able to see the spinal nerves entering/exiting the spinal cord cavity between the vertebrae – lift them with a probe. The vertebra will be soft enough to slice the top off with a scalpel and you will be able to view the spinal cord in-situ.
This website is an excellent resource for piglet dissections and the skull and spinal cord sections are very clearly described with photos. http://www.whitman.edu/content/virtualpig
Top Tip: How to use small intestines in the classroom
I heard this from a lab tech from northern NSW at ConQEST. She did such a good job with the small intestine in the science classes that now she’s asked to bring it into the hospitality classes as well.
She puts the specimen into an ice cream container and lets a little bit hang over the side. Then she gets the kids to gather around and guess at what it is. They can touch it at this stage but they can’t see what it looks like in the container.
After a while they get to see it all coiled up in the container and everyone gets around to working out that it’s a small intestine. Then they start to wonder how long it is. They’ve heard that these things can be metres long, so they are allowed to start extending it out.
They pull and they pull and they pull. Eventually they are all standing holding this thing and then the labbie gets the tape measure out. It’s around 6m long.
All the while these kids have been hearing about what the purpose of the small intestine is, where it fits in the jigsaw puzzle that is your abdominal cavity and what it connects to and so on. They are fascinated by the thing and asking lots of really good questions. Before they know it these kids can spout off all sorts of fun facts about their digestive system. Teaching by stealth – I love it!
The specimen is tough enough to handle this over and over again. You will store it quite happily in the fridge for years before you need a new one. If you’re willing to you can sacrifice a little bit and make a wet mount to be viewed under the microscope. Look out for the little ‘hairs’ along the edges – those are the remnants of all the circulatory system structures that bring oxygen to the small intestine and carry fluid away from it.
This is definitely a specimen that gives you a lot of bang for your buck.
