Stress (7 & 8) Flashcards
(10 cards)
What is stress in biological terms?
Stress is a real or perceived threat that disrupts homeostasis, activating biological responses to restore balance and ensure survival.
What biological and behavioral mechanisms are triggered by acute stress?
Acute stress activates the sympathetic nervous system and HPA axis, releasing adrenaline and cortisol, which increase heart rate, energy availability, and alertness for a fight-or-flight response.
How do stress mechanisms adjust body activity to optimize survival?
They enhance cardiovascular output, energy mobilization, and sensory awareness, while suppressing non-essential functions like digestion and reproduction.
What brain structures are involved in processing stress?
The cerebral cortex, limbic system, hypothalamus (especially PVN), and brainstem integrate sensory input and orchestrate stress responses via the HPA axis and autonomic outputs.
How are different types of stress interpreted in the brain?
Physical stress activates direct hypothalamic pathways, while emotional stress involves the limbic system. Both converge at the hypothalamus to trigger a unified hormonal response.
How does the brain coordinate endocrine, autonomic, and behavioral responses?
Through CRH release from the hypothalamus, activating the HPA axis and sympathetic system, synchronizing hormonal (cortisol, adrenaline), autonomic, and behavioral outputs.
How can stress responses be measured?
Via cortisol levels in saliva, blood, or hair; autonomic measures like heart rate variability; and psychological interviews assessing perceived stress levels.
What role does the brain’s biological clock play in stress response?
The suprachiasmatic nucleus aligns cortisol rhythms with daily activity cycles, optimizing readiness in the morning and reducing stress responses at night.
What are the adverse effects of long-term stress hormone exposure?
Chronic high cortisol can lead to immune suppression, obesity, hypertension, type 2 diabetes, anxiety, depression, and even cognitive decline.
How are stress hormones linked to mental illnesses like depression?
Chronic cortisol elevation disrupts neurotransmitter balance (e.g., serotonin, noradrenaline) and impairs HPA feedback, contributing to depression and anxiety.
