CAS PS 332 Lecture Notes - Lecture 5: Allostatic Load, Stress (Biology), Peripheral Nervous System
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Published on 22 May 2019
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Lecture 5: 2/5/19
• Health Disparities Within the US
o Health disparities = differences in health outcomes or experiences of
disease that are observed between populations
▪ Slides
• What is stress?
o Environmental event (“stressor”)
▪ Disrupts homeostasis
▪ Situation (acute or chronic) or event
o Psychological state
▪ Anticipation of disrupted homeostasis
▪ Cognitive / emotional
o Physiological response
▪ Attempt to regain homeostasis
• Biopsychosocial model breakdown
• APA stress poll
• Why is stress important?
o Allows us to stay safe
o Mobilizes energy- Fight or Flight
o Allostatic load: constancy in the state of change; what’s adaptive in any
given time is different, allows for change. Load = cumulative long term
effects on body from stress. Higher load = higher likelihood of developing
chronic stress related illnesses.
• Nervous system
o Basic functions: integrate and control body systems, and interface
between body and environment
o Basic neuron structure
o Central vs Peripheral nervous system
▪ Peripheral - somatic and autonomic
▪ Autonomic- sympathetic and parasympathetic
o Neuroendocrine
▪ Subset of endocrine system; glands that interact with nervous
system
▪ Hormones = chemicals that travel through the bloodstream
▪ Act on specialized receptors, directly change target organ,
indirectly secrete other hormones
▪ HPA Axis: Hypothalamus, Pituitary, Adrenal Cortex (long term)
• Negative feedback loop, impaired with chronic stress
▪ SAM Axis: releases norepinepherine and epinepherine, stimulates
nerves in the adrenal medulla; impacts fight or flight (short term)
▪ There are two pathways for short term and long term adaptation
and survival
• Theories of stress
o Selye: General adaptation syndrome
▪ Injected hormones into rats
▪ In both rats, he saw ulcers, enlarged adrenal glands, shrunken
immune tissue
▪ This suggests that there are varied type of stressors, including the
psychological impact of getting a repeated injection
▪ With different types of stressors, same physiological response
▪ Stress can make you sick