Final answer:
Increased plasma cortisol primarily stimulates gluconeogenesis and glycogenolysis in the liver, proteolysis in skeletal muscle, and lipolysis in adipose tissue. These effects work together to increase the availability of glucose and fatty acids in the blood, which supports energy production during stress or fasting.
Step-by-step explanation:
The major effects of increased plasma cortisol concentrations on energy storage are noticeable across the liver, skeletal muscle, and adipose tissue. In the liver, cortisol stimulates gluconeogenesis and glycogenolysis, processes that lead to the synthesis of glucose from non-carbohydrate sources and the breakdown of glycogen into glucose respectively. Cortisol and other glucocorticoids like corticosterone and cortisone, released in response to ACTH, increase the breakdown of proteins in skeletal muscle, producing amino acids that are then converted into glucose in the liver. In adipose tissue, cortisol promotes lipolysis, the breakdown of stored triglycerides into fatty acids and glycerol which can be used as fuel. Hormones like glucagon and epinephrine also stimulate these processes, while insulin is the main hormone that inhibits glucose uptake into cells.