Chancellor said the teacher learned the same lesson when she was in college and thought it would be effective in her own classroom.
"The idea of the lesson was to demonstrate the tensile strength of the organ," she said. "However, we understand that best practices change over time, and we believe there is a more appropriate way to demonstrate the concept."
During the lesson earlier this month, some students shot Snapchat video. The clips caught the attention of People for the Ethical Treatment of Animals, which used the footage to highlight PETA's stance on classroom dissections.
"Every year, over 10 million animals are killed for classroom dissection - they don't die from natural causes," the animal-rights group wrote online. "They're stolen from the wild, taken from animal shelters, or killed in slaughterhouses.
"Dissection is bad science: 98 per cent of medical schools don't require it, studies show that students are less interested in science after being forced to dissect, and it's a super-archaic, cruel way to teach biology and anatomy."
PETA added: "Churchill officials have an obligation to ensure that this never happens again - they need to end all animal dissection immediately. Allowing dissection to continue endorses callousness, disrespect, and cruelty to animals."
Chancellor, the district spokeswoman, told KENS that district administrators believe the lesson plan may need to be updated.
"At this point, we don't think that we will be using this same lesson," she told the news station. "Moving forward, we will need to find a more appropriate but equally effective lesson in the future."
PETA said in an email to mySA.com that it has suggested that the district use alternative methods to classroom dissection, such as computer games.
The district told the newspaper that dissections are "common" and will continue to be used as part of the curriculum, adding that it's "too early" to say whether alternative methods may be adopted.