Chapter 2 - Homeostasis & Allostasis

Question 1

Differentiate between homeostasis & allostasis

Answer 1

• Homeostasis: A state in which all systems are in balance (equilibrium or ideal set point) and is established by negative-feedback loops
• Allostasis: A regulatory process/mechanism controlled by the brain that has the ability to successfully adapt to challenges (re-establishes homeostasis)

Question 2

Define Stress

Answer 2

• Stress: A physical, chemical, and/or emotional factor resulting in tension of the body or mind and a real or perceived threat to homeostasis
• May be direct consciously or indirect unconsciously sensed
• The brain cannot differentiate between a real or perceived threat (ex. being chased or worrying too much)

Question 3

Define Eustress

• What occurs with low-stress levels?

- What occurs with high-stress levels?

Answer 3

• Eustress: The optimal amount of stress linked to best performance (motivation to accomplish)
• Low-stress results in rust-out (boredom)
• High-stress results in burn-out (distress) and the body begins to reacts negatively (detrimental)

Question 4

Define GAS

Answer 4

General Adaptation Syndrome by Selye

Question 5

What is the first stage of GAS; explain

- Men vs. Women

Answer 5

Alarm: burst of energy and short lived

• Fight or flight response
• HPA Axis
• Sympathetic-Pituitary-Medullary System –> Catecholamines (Norepinephrine/Epinephrine) … Cardiac (increased rate), respiratory (increased rate), skin (decreased temperature), hormonal (increased stimulation of adrenal genes = adrenaline rush)
• Women are different than men = seek support when stressed (endorphins/oxytocin produced by body to create sense of protection and calmness)

Question 6

What is the second stage of GAS; explain

Answer 6

Resistance/Adaptation:

• Activity of nervous & endocrine system returning body to homeostasis
• Allostatic activity of various system attempts to restore homeostasis
• If the threat is gone, responses gradually go back to normal

Question 7

What is the third stage of GAS; explain

- Note: Allostatic Overload

Answer 7

Exhaustion: the body shuts down
- Point of no return to homeostasis for the body

• Allostatic Overload: “cost” of body’s organs/tissues for excessive or ineffectively regulated allostatic response; effect of “wear and tear” on the body
• May generate diseases or disorders
• As duration of time increases, stress increases

Question 8

Define Stressor

Answer 8

Stressor: Agents or conditions that produce stress; endanger homeostasis

• External or Internal
• Physical, chemical, biological, social, cultural, psychological
• Vary in scope, intensity, and duration

Question 9

What are the 4 responses to stress (name examples)?

Answer 9

1) Physiological - Increased heart rate & tense muscles
2) Cognitive - Worrying, lack of concentration, forgetfulness
3) Emotional - Anger, sense of dread
4) Behavioural - Less patient, hurrying

Question 10

Define Risk Factor

Answer 10

Not a stressor but a condition or situation that increases the likelihood of encountering a stressor
- Ex. Texting and driving

Question 11

How does one adapt and cope from stress?

Answer 11

• Individuals respond to stress differently; changes with time and circumstances

Question 12

What are the effects of stress response influences by?

Answer 12

• Genetics
• Socio-economic status
• Prior susceptibilities
• Pre-existing health status
• Allostatic state
• Ability to manage stress

Question 13

Coping with stress:

- Within vs. Without of your control

Answer 13

• Within = active coping strategies

- Without = passive coping strategies

Question 14

Define Adaptation

Answer 14

Biopsychosocial process of change in response to new or altered circumstances (internal or external in origin)

Question 15

Define Coping

Answer 15

Behavioural adaptive response to a stressor using culturally based coping mechanisms

Question 16

Define Adaptation and Coping

Answer 16

Terms used interchangeably

Question 17

Define Distress

Answer 17

Perceived inability to cope with a stressor

Question 18

Name and define the two adaptation methods for stress ***

Answer 18

1) Habituation: Learning
2) Desensitization: Learn the ability to control stress response after repeated exposure
- Biofeedback - initially developed for individuals suffering pain = learned to control stress response thus no damage to the body
- Visualisation or mediation

Question 19

Define Allostatic Overload

- What does it lead to?

Answer 19

Inadequate adaptation mechanisms or excessive allstatic load; results in inability to maintain homeostasis

• Leads to various illnesses and disorders (physical/emotional)
• Chemical mediators from stress response contribute to various illnesses (cortisol, catecholamines, cytokines)

Question 20

Effects of allostatic overload

Answer 20

See Table

• Nervous System
• Cardiovascular System
• Gastrointestinal System
• Gentiourinary System
• Integumentary System
• Respiratory System
• Immune System
• Endocrine System
• Musculoskeletal System

Question 21

What are the “I’m in control distress relief strategies”?

Answer 21

• Feeling good about yourself
• Eliminate unnecessary worry

1) Get physical
2) Get mental
3) Get spiritual
4) Body and mind tactic
5) Develop new skills

Question 22

Describe the HPA Axis

Answer 22

Hypothalamic-Pituitary-Adrenal Axis

• Receptors become excited by stressful stimuli and relay information to the hypothalamus
• The hypothalamus then signals the adrenal cortex (via anterior pituitary and release of adrenocorticotropic hormone) and the sympathetic pathways (via autonomic nervous system)
• The stress response of the sympathetic pathways is mediated by catecholamines (epinephrine and norepinephrine)
• The stress response of the anterior pituitary is mediated by corticosteroids (glucocorticoids and cortisol)