Life Events Model of Stress

Study Notes

Research indicates that daily hassles (e.g., traffic, noise) contribute more to illness than major life changes.
Shares methodological flaws with the Life Events Model, such as the influence of neuroticism on self-reports.
Hassles scales are utilized in health research related to conditions like asthma and fibromyalgia.
Sometimes combines significant life events (SLE) with hassle measures for health problem studies.

Psychoneuroimmunology (PNI) is the study of psychological, neurological, and immunological interactions, first published by Solomon and Moos in 1964.
PNI explores how stress influences 50-80% of illnesses, establishing itself as a validated field backed by numerous studies.

Protects against harmful exogenous (external) and endogenous (internal) threats, collectively known as antigens.
Comprised of multiple defense layers, including skin and mucous membranes that hinder bacteria.
Innate immune system offers immediate, non-specific responses without memory of prior invaders.
Adaptive immune system develops memory for specific pathogens, providing a focused response after initial exposure.
Activation of the adaptive immune system takes approximately 4-5 days following a new invader.

Inflammation is marked by heat, redness, pain, and swelling, reacting to tissue damage or infection.
Neutrophils, the most common white blood cells, are first responders in the inflammatory process.
Phagocytes, including neutrophils and monocytes, engulf and digest invading antigens.

Granulocytes (neutrophils, eosinophils, basophils) participate in allergic and inflammatory responses.
Monocytes migrate into tissues, enlarging to become macrophages, effectively attacking pathogens.
Natural killer (NK) cells target and destroy "non-self" cells like tumor and virus-infected cells.
Lymphocytes include T cells (thymus-derived) and B cells, crucial for adaptive immunity.

A balanced Th1/Th2 immune response is essential for preventing chronic inflammation and autoimmune disorders.
Th1 and Th2 cells regulate each other’s functions, maintaining homeostasis in the immune response.

In acute stress, the sympathetic-adrenal medulla (SAM) and hypothalamic-pituitary-adrenal (HPA) axes activate, releasing catecholamines and glucocorticoids.
Norepinephrine temporarily boosts immunological activity, enhancing leukocyte mobilization and NK cell proliferation, preparing the immune system for potential threats.