General Information

Lab 7 is the only dissection in the lab manual. Although students really look forward to it, there is some trepidation. Because of this, Lab 7 has some safety considerations.

Talk to students about being prepared and healthy, including:

• Reading over the lab.
• Watching the dissection video (link below).
• Getting a good night’s rest.
• Eating breakfast before coming to the lab.

Also, talk to your students about what to do if they feel ill (e.g., nauseous, dizzy, or lightheaded), such as sitting down immediately and/or telling a friend. These incidents are uncommon, but it is always better to be proactive than reactive.

Caution students that they should treat the hearts in the same way they treat any raw meat in their kitchens. Ensure that they are washing their hands thoroughly and sanitizing their workspace.

The following video shows a full heart dissection, which follows the instructions in the lab manual. You can share the link with your students before the lab.

• Heart Dissection (26:32 min) by Learn Basic Biology (2020)

Purchasing Information

Thompson Rivers University is lucky to have a Retail Meat Processing program, and I buy fresh or frozen pig hearts directly from them. This option is less expensive than buying preserved hearts from a lab supply company and has the added benefit of the hearts not smelling bad from the preservatives.

If you do not have a source at your institution, you can buy pig hearts from a local butcher. Furthermore, if you have friends who hunt, deer hearts also work well too, although they are bigger than pig hearts.

The hearts keep fairly well in the freezer (if properly bagged) and last about a year before becoming too freezer-burnt.

Required materials for Lab 7 include:

• A class set of dissection trays (glass or plastic foodware dishes also work fine)
• A class set of dissection scissors (scalpels do not work as well for this type of dissection)
• A class set of probes
• Latex or vinyl gloves — For students who wish to use them
  • Buy medium to extra large sizes (smalls seem to only fit children)
• Fresh or preserved pig hearts (see discussion above) — 1 heart for every 2 students
  • Keep a couple of spare hearts in case any are damaged.

Lab Setup

Preparations

Tasks:

• Preorder and prep the pig hearts.

Lab Activity Setup

Time: Approx. 30 minutes

• You can spend some time rinsing the hearts out for the students so they do not find huge blood clots.

Board Notes

Welcome to Lab 7: Heart Dissection

• Please hand in:
  • Post Lab 6
  • Pre Lab 7
• Work with a partner
• Be safe:
  • Be careful with scissors
  • Sit down if you feel lightheaded
  • Ask for help if you need it
• Dispose of hearts in the waste bag provided
• Clean your dishes well with warm, soapy water
• Wipe your lab bench down with disinfectant

Setup Photos

No photos are needed!  Each student pair gets a dissection tray, a probe, a pair of scissors and their heart.

References

Learn Basic Biology. (2020, October 30). Heart dissection [Video]. YouTube. https://www.youtube.com/watch?v=tCNQlpETaOc.