Describe How The Endocrine System Responds When Under Stress

Describe how the endocrine system responds when it is under stress

The primary function of the endocrine system in response to stress involves the activation of the hypothalamic-pituitary-adrenal (HPA) axis. When the body perceives a stressful stimulus—whether physical or psychological—the hypothalamus releases corticotropin-releasing hormone (CRH). CRH stimulates the anterior pituitary gland to secrete adrenocorticotropic hormone (ACTH), which circulates to the adrenal cortex and prompts the release of cortisol, often called the "stress hormone." Cortisol plays a vital role in mobilizing energy reserves by increasing gluconeogenesis, stimulating lipolysis, and promoting protein breakdown. It also exerts immunosuppressive effects to prevent overactivation of the immune system during prolonged stress (Tsigos & Chrousos, 2002). Furthermore, the sympathetic nervous system stimulates the adrenal medulla to release catecholamines—epinephrine and norepinephrine—which elicit immediate physiological changes such as increased heart rate, blood pressure, and energy supply. This coordinated response prepares the body to either confront or evade a perceived threat, exemplifying the body's rapid and integrated effort to manage stress (McEwen, 2007).

Describe how the endocrine system responds when it is at rest

During periods of rest, the endocrine system maintains homeostasis by regulating metabolic processes and facilitating recovery from stress. The hypothalamus decreases CRH production, leading to reduced ACTH and cortisol secretion, thereby allowing the immune system to function optimally and energy stores to replenish. The parasympathetic division predominates, promoting processes such as digestion, absorption of nutrients, and tissue repair. The thyroid gland secretes thyroid hormones (T3 and T4), which help regulate basal metabolic rate and energy expenditure during rest. The pancreas secretes insulin to facilitate glucose uptake and storage, supporting anabolic processes that rebuild glycogen, fat, and protein reserves. The gonads produce sex hormones—testosterone and estrogen—that mediate reproductive functions and secondary sexual characteristics. Overall, during rest, the endocrine system supports growth, repair, immune competence, and the maintenance of energy balance, crucial for restoring the body's optimal functioning after stress (Braverman & Utiger, 2005).

References

• Braverman, L. E., & Utiger, R. D. (2005). The thyroid: a fundamental and clinical text. Lippincott Williams & Wilkins.
• McEwen, B. S. (2007). Physiology and neurobiology of stress and adaptation: Central role of the brain. Physiological Reviews, 87(3), 873–904.
• Tsigos, C., & Chrousos, G. P. (2002). Hypothalamic-pituitary-adrenal axis, neuroendocrine factors and stress. Journal of Psychosomatic Research, 53(4), 865–871.