Final answer:
Regular or crystalline insulin is administered via subcutaneous injections to manage blood glucose levels in people with diabetes, particularly after a high-glucose meal. This method is suitable for home administration, unlike intravenous or intramuscular routes which are used in healthcare settings.
Step-by-step explanation:
In the context of insulin therapy, the appropriate administration method for regular or crystalline insulin is a subcutaneous injection. This method is typically used to manage blood glucose levels in people with diabetes, especially after consuming a large or high-glucose meal. Insulin injections work by facilitating the transport and storage of glucose, thereby helping to decrease blood glucose levels to prevent hyperglycemia. It's important to know that insulin also allows transport of glucose into cells to be used as energy. Subcutaneous injections are convenient for home administration and are less invasive compared to other methods like intravenous or intramuscular injections, which are usually given in healthcare settings when higher plasma levels of medication are required.