NBEO General Physiology Practice Exam

Cortisol, a steroid hormone produced by the adrenal glands, plays a significant role in various physiological processes, especially in response to stress. It influences glucose metabolism, immune response, and bone health, among other functions.

One of the characteristics of cortisol is its ability to increase blood sugar levels. This happens through gluconeogenesis in the liver, where the body produces glucose from non-carbohydrate sources. This increase in blood sugar is a key feature of cortisol’s function, especially during stress when energy availability is crucial.

Cortisol also has immunosuppressive effects. It inhibits various aspects of the immune system, reducing inflammation and altering the activity of immune cells. This is why synthetic cortisol or corticosteroids are often used to treat inflammatory and autoimmune conditions.

Another effect of cortisol is the slowing of bone formation. Chronic high levels of cortisol can lead to decreased bone density, as it inhibits the activity of osteoblasts, the cells responsible for bone formation, and promotes the activity of osteoclasts, which break down bone tissue. This imbalance can ultimately lead to osteoporosis.

The key distinction lies in the effect on peripheral insulin resistance. Cortisol actually increases peripheral insulin resistance rather than decreasing it. This means that while it raises blood sugar levels,