Cortisol is a useful adrenal hormone because it .
a. always is part of a negative feedback loop

b. ensures that adequate glucose is available to the brain when needed

c. causes all cells to take up glucose

d. reduces the size of the hippocampus

e. cannot be subject to overproduction

B) cortisol ensures that the brain has glucose when it’s necessary. Cortisol is a steroid hormone that helps control blood sugar levels, metabolism, and inflammation. Glucose, also known as sugar, is an energy source used in cells in the body. The brain is highly demanding of energy since it is so rich in nerve cells and neurons, so glucose is essential to the brain. Too much can harm the brain though, so it is important for the cortisol to control the sugar levels.