What causes secondary dilution during the embalming operation?

The correct answer is the movement of blood and lymph during the embalming process, which leads to secondary dilution. This phenomenon occurs when embalming fluids introduced into the body mingle with the existing fluids present, primarily blood and lymph. When embalming fluid is injected into the vascular system, it displaces and interacts with these bodily fluids, creating a diluted mixture around the tissues.

This dilution process is significant because it impacts how effectively the embalming chemicals can permeate and preserve the body tissues. As blood and lymph provide a medium through which the embalming fluid travels, understanding this dynamic is crucial for proper embalming procedure, ensuring that the body is adequately treated and preserved.

Other options, while relevant to the processes during embalming, do not directly cause secondary dilution in the same way. Tissue reaction refers to the body's response to the embalming chemicals; gas formation results from decomposition processes or chemical reactions; and water absorption concerns how body tissues interact with fluids but does not specifically relate to the dilution caused by blood and lymph during the embalming operation.