Skin Removal

  1. RESPECT First off, respect the specimen. Remember it was a living thing and that the purpose of dissection is learning - not destruction. Also, respect your peers. Everyone reacts to dissection in a different way; some people are fine with it the moment they enter the room, others need a few days or even weeks to become ok with it. Show your peers that you respect them by being patient and giving them the time they need to get accustomed to it. In other words, don't tease or taunt! Inappropriate behavior will not be tolerated.

  2. Work carefully! We will be methodically exposing various structures to be studied. Follow directions carefully (ask if you don't understand) and don't do anything that you are not instructed to do. You don't want to damage or destroy any structures that you will be studying later in the dissection (including blood vessels and nerves). Use the photos & diagrams in your lab manual and handouts for guidance.

  3. Dissection Instruments Scalpels are primarily used for making incisions, so use them sparingly. Don't use them too much - you can easily cut into structures by accident. However, using the back of the scalpel can be useful for separating the skin from muscle. Just be careful not to twist the blade - if it breaks, see your teacher for a replacement. Dissecting needles will be your best friends - they are good for separating muscle and tracing delicate structures. Scissors, like scalpels, should be used sparingly. Be sure you know exactly what you are cutting into before you do it! Blunt probes are handy for holding back organs or exploring an area without damaging delicate structures. Forceps are also handy tools for holding structures out of the way. Experiment using the different types for different purposes. Pins are also available if you need them to hold structures out of the way. Finally, your hands are some of the best tools you can use - don't be afraid to get in there!

  4. Safety Concerns Report any accidents to your teacher immediately! Scalpels are sharp, so be careful - never cut towards your (or your partner's) hand. Always wear gloves and goggles to limit skin exposure to the preservative. We will keep the room as well-ventilated as possible. If you need a break for some fresh air, let your teacher know and then step out until you feel better.

  5. Beginning the Day Line your dissection tray with paper towels to absorb fluids and to hold any materials to be discarded. You will need to keep both bags that the cat comes in, so you can double-bag it for storage. Label the outer bag with your names, then cut open the bags as close to the top as you can. Pour any fluids into the sink and rinse off the cat as best you can to wash off the smelly preservatives. Lay your cat on the dissection tray and begin following your checklist. Copy the definitions of any new terminology for your A&P notes.

  6. Skin Removal Read and follow the instructions in the lab manual (p. 18-20) carefully. Keep the skin intact in one piece. Again, use the scalpel blade only to make incisions. The back of the scalpel, a blunt probe, and your fingers are the best tools for separating the skin from muscle. Areas to be especially careful are the armpit area where the latissimus dorsi insert on the abdominal muscles. Once the skin is completely removed, begin removing excess connective tissue and fat until the muscle fibers are clearly visible.

  7. Clean-Up Procedures Wrap the cat in its skin and then in moist paper towels to keep it from drying out. Place the cat back in the inner bag. Twist the top, then fold it over and secure with a rubber band to minimize leakage. Do the same with the outer bag. Place the cat in your class's bin for storage. Discard the paper towels, wash and dry the dissection tray, and return the tray to the supply area. Wash and dry any instruments used, then return them to the supply area. Wipe down your lab bench with the bleach solution and make sure your sink is clean. Finally, wash your hands.

  8. Materials:

2 fans

Lab manuals

Dissecting trays

Paper towels

Gloves - latex, nitrile, vinyl

Goggles

Scalpels & replacement blades

Dissecting needles

Scissors

Blunt probes

Forceps

Dissecting pins

Bleach solution in spray bottles

Preservative spray

Rubber bands

Rubbermaid bins - 1 per class