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Stress. Stress affects even most seemingly Tranquil lives. What is stress and why do we need it? * Reflecting Difficulties of Interacting with others as we work towards academic success * Stresses are physical such as an acute illness or broken leg in a car accident
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Stress • Stress affects even most seemingly Tranquil lives
What is stress and why do we need it? * Reflecting Difficulties of Interacting with others as we work towards academic success * Stresses are physical such as an acute illness or broken leg in a car accident * Molecules have evolved which provide a series of emergency systems that protect key cellular functions from unexpected external challenges * Special molecules called heat-shock proteins * Cellular protection mechanisms as building blocks in a larger network of stress protection • Stress and the brain * Cognitive appraisal of Situation in Brain Interacts with bodily Signals in Blood Stream such as Hormones, Nutrients and Inflammatory Molecules * Circulating Hormones in Blood are Monitored by Brainto enable Body to cope with Stress
Hypothalamic-pituitary adrenal(HPA) axis * MajorNeuroendocrine response to Stress is Activation of Circult Linking Body and Brain called the HPA Axis * Hypothalamic is strong Inputs from Areas of Brain Processing emotional Information * Cortisol is a steroid Hormone that is Key to Underst anding the next Phase of Stress Response * Last Step of Circuit is Cortisol Feedback to Brain
Tale of two Cortisol Receptors and Shrinking Hippocampus * Two Receptors for Cortisol- let's call low MR, high GR * Low MR Receptor is activated by normally Circulating Levels of Cortisol in Blood Stream Highway of HPA Axis - this keep general Metabolism and Brain Processing Ticking over nicely * High GR Receptor becomes progressively more occupied * We become Stress, Cortisol Levels become very higt indeed, activation of Receptor is sustained
Stress and Ageing * Ageing of Brain is accompanied by general Decline in Function * Cortisol Levels are Higher in unsuccessful than in Successful Ageing * Experiments in Rats have shown that keeping Stress Gormone Levels low from Birth * Exploiting Antidepressant Drugs that keep HPA Stress System under Control → Major Feature of Modern Life