Lecture 1.5 Flashcards
Stress and Physical Adaptation
What is Stress?
It is the body’s reaction to harmful forces (Stressors) that are capable of disturbing our homeostasis.
Characteristics include:
Real or perceived
Short or long-term
Isolated or recurrent
3 Manifestations of Stress
Routine Stress: everyday issues like work, school, etc.
Episodic Acute Stress: Transient, out-of-the-ordinary events such as loss of job, death in the family, major illnesses, etc.
Traumatic Stress: Life threatening events such as war, famine, assault, major accidents, etc.
Anxiety
The vague, uneasy feeling of discomfort or dread, which is often accompanied by an autonomic response (fight or flight)
Stressors
Any physical, physiological, or psychological force that is capable of disturbing our homeostasis equilibrium.
Homeostasis
A state of dynamic equilibrium of the internal body. It is maintained by the ever-changing processes of feedback and regulation in response to external or internal stimuli.
Adaptation
Response of an organism to stress to restore homeostasis and equilibrium.
What about an individual can affect their response to stress?
Age, General Health, Social Support, Genetic Influences, and Nurture Influences.
Stressor characteristics
The Type of Stressor: routine, episodic, traumatic
Persistence of Stressor: chronic or short
Perception of Stressor: How we perceive the stressor.
Origin of Stressor: Endogenous or Exogenous
Two types of stressors
Endogenous- from within
Exogenous- from without
Eustress (stressor)
Mild, brief, controllable periods of stress that can be perceived as POSITIVE stimuli to emotional and intellectual growth and development
Distress
Severe, protracted, and/or uncontrolled situations of psychological and physical distress that are disruptive to health
Fight or Flight Response Purpose
Meant to protect the person against acute threats, time limited, useful especially in immediate physical threat, NOT so useful to stressors like work or exams
How does stress affect the two ANS pathways?
Activates sympathetic (fight or flight), deactivates parasympathetic (rest and digest)
Neurological Responses to Stress (5)
Brainstem: Coordinates our body’s response
ANS: Coordinated by locus caeruleus (LC)
Increased: BP, HR, RR, pupil dilation, sweating, skeletal muscle, heart, and lung blood flow
Decreased: gastric function, peripheral blood flow and other viscera.
Cerebral Cortex: Regulates cognitive activities like focus, planning, attention, and persistence.
Limbic System: Regulates emotional activities and the reticular activating system (RAS).
Limbic includes fear, anxiety, anger, and excitement.
RAS includes alertness, muscle tension, and ANS stimulation.
Thalamus: Regulates and intensifies sensory input, such as our vision, hearing, or smell.
Hypothalamus: Regulates stress hormones and acts on the ANS.
Endocrine Response to Stress (4)
Release of 4 hormones: Cortisol, Dopamine, Epinephrine, and Norepinephrine.