Choose the correct answer from the options given below:

Trace the sequence of events followed by the exposure to prolonged stress
A. Glucocorticoids are released by adrenal cortex
B. Lymphocytes are activated
C. Hippocampal cells get degenerated
D. Anterior pituitary releases ACTH
E. T-cells and B-cells get activated

Correct option is C

The correct answer is D → A → B → E → C.
1. The stress response begins with the hypothalamic–pituitary–adrenal (HPA) axis activation. Initially, the hypothalamus signals the anterior pituitary to release ACTH (Adrenocorticotropic hormone). Hence, D is first.
2. ACTH stimulates the adrenal cortex, which in turn releases glucocorticoids (mainly cortisol) into the bloodstream. Hence, A follows.
3. As a physiological response to stress, immune cells like lymphocytes are activated, including T-cells and B-cells, to prepare the body to defend against possible threats. Hence, B and E follow.
4. In chronic stress, elevated cortisol levels lead to hippocampal cell degeneration, affecting memory and learning. Hence, C comes at the end.

Information Booster
Physiological Response to Prolonged Stress

1. HPA Axis Activation:
The hypothalamus, upon detecting a stressor, activates the pituitary gland, initiating the release of ACTH, which stimulates adrenal gland activity.

2. Adrenal Cortex and Glucocorticoids:
ACTH prompts the adrenal cortex to release cortisol (a glucocorticoid), which helps regulate metabolism, immune responses, and stress adaptation.

3. Immunological Response:
Initially, stress can cause temporary activation of the immune system (lymphocytes, T-cells, and B-cells). However, prolonged cortisol elevation eventually suppresses immune function.

4. Role of Cortisol:
While short-term cortisol helps mobilize energy and resources, long-term exposure is neurotoxic, particularly to the hippocampus, impairing memory and learning.

5. Hippocampal Damage:
Chronic cortisol exposure causes atrophy of hippocampal neurons, a phenomenon observed in stress-related disorders like depression and PTSD.

6. Immune Suppression with Chronic Stress:
Over time, prolonged cortisol exposure reduces immune efficiency, increasing vulnerability to illness.