ATI Pathophysiology Practice Exam

Type 1 diabetes mellitus is characterized as an autoimmune disorder wherein the body's immune system mistakenly attacks and destroys the pancreatic beta cells responsible for producing insulin. This destruction leads to an absolute deficiency of insulin, which is essential for the regulation of glucose in the bloodstream.

On the other hand, type 2 diabetes mellitus primarily involves insulin resistance, where the body's cells become less responsive to insulin, requiring more of the hormone to achieve the same regulatory effect on blood glucose levels. Type 2 diabetes is frequently associated with obesity and lifestyle factors, making it more common in overweight individuals, but it can also occur in those of normal weight.

This differentiation is critical in understanding the distinct pathophysiological mechanisms behind each type of diabetes. While type 1 involves minimal or no insulin production due to autoimmune destruction, type 2 revolves around the body's inability to effectively use insulin, typically occurring over time due to factors such as excessive weight and sedentary lifestyle. Thus, the correct choice provides a clear distinction between the two types, highlighting their underlying causes and mechanisms.