Final answer:
Cortisol levels rise after waking up to maintain blood glucose levels and help the body respond to stress by mobilizing energy reserves and ensuring homeostasis.
Step-by-step explanation:
Cortisol levels peak in the first few hours after waking in order to help maintain blood glucose levels, stimulate appetite, and prepare us for potential stressful situations. Glucocorticoids such as cortisol, corticosterone, and cortisone are fundamental in regulating the body's response to stress. Cortisol works by stimulating the synthesis of glucose and gluconeogenesis (converting a non-carbohydrate to glucose) by liver cells, promoting the release of fatty acids from adipose tissue, and increasing blood glucose to maintain normal levels between meals. This process helps to ensure that long-term energy requirements can be met and prepares the body for stressful events by mobilizing lipid and protein reserves, conserving glucose for neural tissue, and maintaining homeostasis.