- The hormone cortisol is primarily secreted by the adrenal cortex, which is the outer layer of the adrenal glands located on top of the kidneys.

- Cortisol plays a crucial role in the body’s response to stress by helping to regulate metabolism, reduce inflammation, and assist in controlling blood sugar levels.

- The anterior pituitary gland secretes hormones like ACTH (adrenocorticotropic hormone), which stimulates the adrenal cortex to produce cortisol, but it does not secrete cortisol itself.

- The thyroid gland is responsible for producing hormones that regulate metabolism but is not involved in cortisol production. The pineal gland secretes melatonin, which regulates sleep cycles, not cortisol.

Therefore, the adrenal cortex is the correct and essential component of the endocrine system that secretes cortisol in response to stress.

Reference: Endocrinology, 7th Edition, Chapter 12 / Page 345