Overview
This lecture covers the physiology of the acute stress (fight or flight) response and its two hormonal pathways, the harms of chronic stress on the musculoskeletal, cardiovascular and metabolic systems, the physical and mental conditions associated with stress, and how problem-focused and emotion-focused coping strategies work to manage it.
Pressure, Acute Stress and the Fight-or-Flight Response
- The lecture treats acute stress and chronic stress as two contrasting categories.
- A stressor/pressure is illustrated as a physical threat requiring physical action over a short term, producing an acute stress response.
- The fight or flight response produces body-wide changes:
- Eyes: pupils dilate
- Lungs: quick, deep breathing
- Bowel: food movement slows
- Blood vessels: blood pressure increases as major vessels dilate
- Saliva: flow decreases
- Skin: blood vessels constrict; chills and sweating
- Heart: beats faster and harder
- Stomach: digestive enzyme output decreases
- Muscles: become more tense; trembling can occur
Slide 10 embeds a video titled "The Stress Response"; only the static preview frame and title were captured, so its content is not represented here.
Nervous System Organisation
- Central Nervous System (CNS): brain and spinal cord; responsible for sensory activities and storing memories and emotions.
- Peripheral Nervous System (PNS): cranial and spinal nerves; carries messages to and from the CNS and the rest of the body.
- PNS divides into:
- Somatic Nervous System: voluntary movement (muscle movement)
- Autonomic Nervous System: involuntary actions (heartbeat, pupil dilation, etc.)
- The Autonomic Nervous System divides into:
- Sympathetic Nervous System: responsible for the fight or flight response
- Parasympathetic Nervous System: responsible for rest and relax actions (e.g. digestion)
The Two Pathways of the Acute Stress Response
- SNS pathway: the perception of stress activates the sympathetic branch of the autonomic nervous system, causing release of the catecholamine hormones noradrenaline and adrenaline (also called norepinephrine and epinephrine) from the adrenal glands and elsewhere.
- HPA axis (hypothalamic-pituitary-adrenocortical) pathway: the hypothalamus initiates a cascade of hormones ending in secretion of the corticosteroid hormone cortisol from the adrenal glands.
- The integrated action of both pathways together is termed the fight or flight response.
Effects of Chronic Stress
Chronic stress produces sustained physiological harm:
- Constantly mobilising energy at the expense of energy storage, causing more rapid fatigue
- Musculoskeletal problems
- Compromised immune system
- Compromised libido and reproductive system
- Increased/high blood pressure
- Extra sodium retention, affecting the cardiovascular system
- Gastrointestinal problems
Slide 16 ("Effect of chronic stress on musculoskeletal system") is an anatomical illustration with no labels or descriptive text beyond the title; no further detail was given for this system.
Cardiovascular mechanism: plaque builds up inside the artery wall; if the plaque ruptures it forms a blood clot or blocks blood flow completely; heart tissue that does not receive enough blood dies and leaves a scar, i.e. a heart attack.
Metabolic effect - metabolic syndrome (Syndrome X):
- Central obesity
- High blood pressure
- High triglycerides
- Low HDL cholesterol
- Insulin resistance
Physical Conditions Associated with Stress
- Cardiovascular disease
- Diabetes and metabolic syndrome
- Gastrointestinal disorders (inflammatory bowel disease and irritable bowel syndrome)
- Musculoskeletal problems and chronic pain
- Autoimmune diseases, e.g. lupus, multiple sclerosis, Type 1 diabetes
- Asthma, some common viruses (cold virus), ulcers
- Evidence for a link with cancer is, so far, not clear
Example of stress influencing disease susceptibility: ulcers, shown via a diagram of the esophagus and stomach with the ulcer site located in the stomach lining. [slide does not elaborate the mechanism beyond this labelled diagram]
Stress and Mental Health
- Stress is strongly associated with the risk of developing mental disorders.
- Multiple simultaneous sources of stress are highlighted for students: school, work, family, college, friends.
Slide 26 links to an embedded BBC animated video on stress via a YouTube URL; only the static preview frame was captured, so its content is not represented here.
Coping Strategies
Two main types of coping:
- Problem-focused coping: focuses on the stressor itself, reducing its demands or expanding resources to deal with it. Includes information seeking and problem solving, seeking support, and learning new skills.
- Emotion-focused coping: focuses on the response to the stressor, controlling one’s psychological and/or physiological response to it. Includes changing one’s thinking about the stressor, talking with others, and behaviours/activities that help reduce or distract from the stress response.
Healthy coping mechanisms (verywellmind.com):
- Emotion-focused: exercise, listening to music, journaling
- Problem-focused: work on time management, establish healthy boundaries, ask for support
Conclusion for Practice
For patients:
- Stress is common and affects most people
- It affects physical and mental health
- Routine inquiry and treatment is key
- Refer for professional support
For yourself:
- Observe what stresses you
- Observe how it manifests psychologically or physically
- Cultivate healthy coping strategies
- Seek professional support if necessary
Self-test
- Distinguish acute stress from chronic stress as presented in the lecture.
- Describe the fight-or-flight response’s effects on the eyes, lungs, heart and digestive system.
- Outline the hierarchy of nervous system divisions from the CNS down to the sympathetic and parasympathetic branches.
- Describe the SNS pathway of the acute stress response, including the hormones released and their source.
- Describe the HPA axis pathway of the acute stress response, including the hormone released and its source.
- List the physiological effects of chronic stress described in the lecture.
- Explain the mechanism by which chronic stress can lead to a heart attack.
- List the five components of metabolic syndrome (Syndrome X).
- List the physical conditions the lecture associates with stress.
- According to the lecture, how clear is the evidence linking stress to cancer?
- What role does stress play in ulcers, as illustrated in the lecture?
- Distinguish problem-focused coping from emotion-focused coping, giving two examples of each.
- List the healthy coping mechanisms given in the lecture, grouped by whether they are emotion-focused or problem-focused.
- According to the conclusion, what should you routinely do for patients regarding stress, and what should you observe in yourself?
Answers
Reveal answers
- Acute stress and chronic stress are presented as two contrasting categories. Acute stress is triggered by a short-term physical threat/pressure requiring physical action and produces the fight-or-flight response. Chronic stress is sustained and produces harms such as rapid fatigue, musculoskeletal problems, immune compromise, reduced libido/reproductive function, raised blood pressure, sodium retention and GI problems.
- Eyes: pupils dilate. Lungs: quick, deep breathing. Heart: beats faster and harder. Digestive system: bowel food movement slows, saliva flow decreases, and stomach digestive enzyme output decreases.
- CNS (brain and spinal cord) leads to the PNS (cranial and spinal nerves); the PNS divides into the Somatic Nervous System (voluntary movement) and the Autonomic Nervous System (involuntary actions); the Autonomic Nervous System divides into the Sympathetic Nervous System (fight or flight) and the Parasympathetic Nervous System (rest and relax).
- The perception of stress activates the sympathetic branch of the autonomic nervous system, causing release of the catecholamine hormones noradrenaline and adrenaline (norepinephrine and epinephrine) from the adrenal glands and elsewhere.
- The hypothalamus initiates a cascade of hormones ending in secretion of the corticosteroid hormone cortisol from the adrenal glands.
- Constant energy mobilisation causing more rapid fatigue; musculoskeletal problems; compromised immune system; compromised libido and reproductive system; increased/high blood pressure; extra sodium retention affecting the cardiovascular system; gastrointestinal problems.
- Plaque builds up inside the artery wall; if the plaque ruptures it forms a blood clot or blocks blood flow completely; heart tissue that does not get enough blood dies, leaving a scar, i.e. a heart attack.
- Central obesity, high blood pressure, high triglycerides, low HDL cholesterol, insulin resistance.
- Cardiovascular disease, diabetes and metabolic syndrome, GI disorders (IBD and IBS), musculoskeletal problems and chronic pain, autoimmune diseases (e.g. lupus, MS, Type 1 diabetes), asthma, some common viruses (cold virus), ulcers.
- Evidence is not clear for a link between stress and cancer.
- Stress is given as an example of a factor influencing disease susceptibility, illustrated with ulcers forming in the stomach lining; the slide does not elaborate the mechanism beyond this labelled diagram.
- Problem-focused coping targets the stressor itself, reducing its demands or expanding resources to deal with it, e.g. information seeking/problem solving and seeking support. Emotion-focused coping targets the response to the stressor, controlling one’s psychological/physiological reaction, e.g. changing one’s thinking about the stressor and talking with others.
- Emotion-focused: exercise, listening to music, journaling. Problem-focused: work on time management, establish healthy boundaries, ask for support.
- For patients, routinely ask about stress since it is common and affects both physical and mental health, treat it, and refer for professional support. For yourself, observe what stresses you and how it manifests psychologically or physically, cultivate healthy coping strategies, and seek professional support if necessary.