Physiological Stress Response PDF

Physiological Stress Response Psychophysiological Response to Stress - in response to stress, there is a - - psychological and physiological response Appraisal: if there is an event and we appraise it to be stressful = physiological stress response If not, no stress response Perception of stress con...

Physiological Stress Response Psychophysiological Response to Stress - in response to stress, there is a - - psychological and physiological response Appraisal: if there is an event and we appraise it to be stressful = physiological stress response If not, no stress response Perception of stress contributes to more stress Video: Fight or Flight - When we can’t face a threat, we push our body to flee it - Adrenaline: heightens all senses to increase focus in order to get out of a dangerous situation Increased HR, BP Floods blood stream with glucose - Body stores energy to prepare for emergency situations; when threatened = energy burst ATP: made by burning glucose or fat FIGHT OR FLIGHT RESPONSE Short-term stressors - Response to event perceived as a stressor - Body goes into action when threatened to save - - itself Body changes to promote that response Body designed for physical stressors: problem = not designed to non-physical stressors - Modern society stressors don’t require movements but body still changes Stress tremors: neurological condition that when stress occurs, leads to trembling GENERAL ADAPTATION SYNDROME Long-term stressors 1. ALARM REACTION — fight or flight Body shows changes characteristics of the first exposure to stressor Its resistance is diminished If stressor is strong/long enough 2. STAGE OF RESISTANCE if continued exposure to the stress is compatible with adaptation Bodily signs characteristic of the alarm reaction have disappeared and resistance rise above normal If prolonged, hyperadaptosis occurs, alarm reaction is maladaptive, causing damage 3. STAGE OF EXHAUSTION following long-continued exposure to the same stressor to which the body has become adjusted Adaptation energy is exhausted Signs of the alarm reaction reappear, but become irreversible Individual may experience symptoms of adrenal failure, body cannot sustain it - i.e. burn out, sleep is important until symptoms resemble depression Physiological Systems Involved in the Stress Response 1. THE NERVOUS SYSTEM Speed ANS Response to stress Sympathetic: responsible for the responses associated with the fight-or-flight response - through the release of cathecolamines (epinephrine and norepinephrine) from kidneys - Stimulate glucose release by liver Parasympathetic: responsible for energy conservation and relaxation - homeostasis through the release of acetylcholine (ACh) - Opposite responses to sympathetic changes ANS regulates visceral activities and vital organs, including - Circulation - Digestion - Respiration - Temperature regulation 2. THE ENDOCRINE SYSTEM — + CHRONIC RESPONSE Endurance over time HPA Axis: Hypothalamus (CRF) => Pituitary (ACTH) => Adrenal (Epinephrine/Norepinephrine/Cortisol) Endocrine system: consists of a series of hormonal glands located throughout the body which regulate metabolic functions that require endurance rather than speed - network of four components: 1. glands: pituitary, thyroid, adrenal 2. hormones: cortisol, CRF, ACTH 3. circulation 4. target organs Cortisol Help the body react/adjust to a chronic stressor, when stressor leaves, sends feedback to hypothalamus to stop response: - catalyzes glucose metabolism - stabilizes blood pressure - maintains normal blood sugar levels - involved in the inflammatory response - facilitate energy production - improve memory capability - Boost immune function - reduce pain sensitivity - precipitate homeostasis Three Stages of Effects Associated with the Stress Response 1. Immediate effects of stress — fight or flight (ANS) sympathetic nervous system 2-3s 2. Intermediate effects of stress adrenal response (adrenal gland [cortex]) Continued release of epinephrine and norepinephrine (medulla [inner]) Usually 20-30s 3. Prolonged effects of stress — HPA axis & Cortisol (Endorcrine system) ACTH , vasopressin, and thyroxine affect various metabolic processes Minutes, hours, days, etc 4. THE IMMUNE SYSTEM - effect of cortisol: suppress activity of the immune system - Leads to increased sensitivity to exposure to diseases/virus/bacteria