Pig Heart Dissection

Before

We had the opportunity to dissect an actual pig heart in class recently! I had a lot of fun doing it but i forgot to take pictures because I had dirty hands from the dissection, so I used some pictures from Bethany's dissection. Thanks! I enjoyed the heart dissection because it was a great experience to see what it all looks like, I sort of felt like a surgeon when I was doing it. It helped me to learn about it more in depth and finding all the parts helped me memorize it a little bit even though I didn't do well on the test. That was just a brief description of the heart dissection that we did in class. Hope you enjoyed!

After

Virtual Leech Lab

Have you ever been to the lake or the mountains with your family and they always tell you to watch out for leeches? These gross worm looking things give me the chills and just ruin the fun when they're on your mind. We were able to do a virtual leech lab on our computers and basically see what kind of cell structure the leeches have. Leeches are 'worms' with suckers on each end. Leeches can range in size from from a half of inch to ten inches long. They are brown or black in color. Some feed on decaying plant material. Others are parasites, feeding on blood and tissue of other animals. Blood-sucking leeches suck your blood using two ways: they use a proboscis to puncture your skin, or they use their three jaws and millions of little teeth. They live just about anywhere where is water. Leeches find you by detecting skin oils, blood, heat, or even the carbon dioxide you breathe out. Leeches do not feed often. This is because they take in a big amount of blood when they feed.

 Step 1: Catch and anesthetized the leech in 20% Ethanol solution

 Step 2: Pin the dorsal side up through the anterior and posterior suckers onto the dissection tray stretching the leech in the process

 Step 3: With the scissors make a cut through the skin along the mid line on the dorsal surface don't go too deep. Next using the forceps carefully pull the skin apart along the cut and than pin down the left & right side.(inside of skin facing up). This will open the leech so you can see the digestive,excretory, and reproductive organs. The nervous system amount show yet because it's located ventrally.

 Step 4: Carefully remove the gut and other internal structures to expose the centrally located nerve cord.The nervous system will be located within the ventral sinus (dark green).

Step 5: Place the leech under the dissection microscope. You will see swellings up and down the sinus. These swellings contain the segmental ganglia of the nervous system. To make them accessible first cut the body wall underneath a ganglion. Make sure you don't damage the nerve cord or any other nerve attached

 Step 6: You will want to isolate a section of the leech. Do this by making two parallel cuts. (perpendicular to the anterior-posterior axis)be sure the side you remove has at least one ganglion. Then,with the forceps flip the piece of skin over so the outer skin is facing up. Pin this down.

Step7: Place this piece of the leech again under the dissection microscope. Cut the sinus with an ultra fine scalpel. ( if this was done in "real" life we would use fine forceps to be sure the ganglion don't get damaged).

Step 8: This is the point we been all waiting for the nervous system.This is when we simulate the process penetrating the cell. To do the penetrating we will use feather, probe or forceps. Weak (feather), medium (probe), strong (forceps) or any stimulus

Step 9: look at the morphology of the neuron from which you have just recorded, by using the Dye Injection and UV on the amplifier system

Step 10:  Try to identify the cell based on published data. There are many cells in different locations of this ganglion. Repeat the whole procedure for as many cells as you would like.

Thank you Sierra Romero for the steps to the dissection!