Kris Wymen narration

1. Week 5:
Physiological
Responses
to Stressors
Slides # to # in recorded
lecture to view prior to
seminar
NRS 232:
Pathophysiology 1
Dr. Kris Weymann
Source: https://www.theverge.com/2016/5/5/11592622/this-is-fine-meme-comic

2. “For there is nothing either good nor
bad but thinking makes it so”
- W. Shakespeare, Othello, Act 2, Scene 2
http://www.ted.com/talks/kelly_mcgonigal_how_to_make
_stress_your_friend.html
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3. Learning Objectives
1. Summarize the pathophysiology of symptoms of stress, such as if the
symptom arises from SNS activation, HPA axis activation, or reticular
activating system activation (and the associated muscle tension from
gamma motor neuron activation).
2. Describe the physiologic consequences of stress, both short term
and chronic.
3. Compare and contrast the physiological stress responses from SNS
activation in someone who is running from danger to the response in
someone who is struggling to pay essential bills and buy food.
4. Name 3 recommendations you could explain to a client who is
interested in learning how to reduce stress and/or the health impacts
of chronic stress.
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4. Outline
1. Physiologic responses to stressors
• Experiences of responses to stress
• What are stressors?
2. Overview of pathways for physiologic response
3. SNS Response to stressors
• Effects of SNS Activation (epinephrine and fight/flight)
4. Musculoskeletal Response to stressors
• Myotatic (stretch) reflex
• Gamma motor neurons and the reticular activating system
5. HPA axis response to stressors
• secretion of cortisol
• normal actions of cortisol
• patient teaching about corticosteroids
6. Other hormonal responses to stressors
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5. Physiologic response
to stressors
• You just took a midterm.
• What were some of the physiologic
responses you experienced prior to
and/or during the exam?
• Or any physiologic responses to a
stressor other than the exam?
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6. The Escape
Ali is being chased. She is frightened.
Describe the physiologic responses that are helping her
escape this situation.
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7. Effects of SNS Activation
Inc HR, inc BP – Fight or Flight
Inc blood sugar-muscles need fuel
Pupils dilate for far vision
Dec. gut motility (blood not to gut-contract sphincters, relax bladder wall
to hold urine)
Vasoconstriction of cutaneous blood vessels –
blood to muscles, & also decreases blood loss from limb if attacked
Increased contractility of skeletal muscles
(hand shaking with first injections given)
Release of cortisol - increases blood sugar
Increased stomach acid
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8. Patti again struggles to pay the monthly bills.
She will again be late with some, and risks
having the electricity cut off, or worse, lose
their home.
What physiologic responses is she likely
experiencing at this moment.
Explain why her shoulder and neck muscles
are so tight they hurt. What underlies that
contraction?
What is the duration of these responses?
What effect do these responses have on her
body and health?
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9. Neuroendocrine response to stressors
• From where is epinephrine released?
• How is the release of epinephrine stimulated?
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10. Overview of pathways for physiologic
response to stressors
Cerebral cortex appraisal of threat &
communicates to limbic system.
Limbic system attaches fear to the threat.
Limbic system communicates to hypothalamus
& to Reticular Activating System (RAS).
Hypothalamus activates SNS & secretes more
CRF, stimulating anterior pituitary-ACTH.
RAS on alert & communicates to skeletal
muscles via gamma, increasing muscle tension.
Internal stimuli, & external ones, may be
interpreted as stressors.
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11. Increased muscle
Tension through gamma
Neuron signaling from RAS
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12. What if you turn on the stress response-too
often, too long
How does chronic stress make us sick?
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13. Shark attack or heart surgery:
Patient teaching about response to stressors
• Antihyperglycemics often short course after surgery (decreases infection
risk)
• Address stomach acid
• Monitor & intervene for constipation
• Monitor & intervene for inc BP
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14. Overview of
Nervous System
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15. Stretch Reflex (Myotatic Reflex)
• Ever have your knee give
out a bit, and you somehow
stay upright?
• When muscle stretched,
reflex contraction occurs—
keeps us standing.
Maintains body position
against the force of gravity.
Also protects muscle from
being overstretched.
• Also causes muscle tension
in response to stressors
because RAS acts to
increase muscle tension.
• When muscle lengthens
(quad lengthens when knee
bends), muscle spindle
stretched & nerve activity
increases via alpha motor
neurons.
• Gamma motor neurons
provide muscle tone at
baseline and adjust tension
on muscle spindles-
involuntarily.
• RAS increases firing thru
gamma motor neurons!
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16. 16

17. FIG 43.41 Diagram of the stretch reflex in which activation of the muscle spindle stimulates contraction of
the stretched muscle. A, Stretch of the muscle sends action potentials to the cord, which make a
monosynaptic connection to motor neurons from the same muscle fibers. B, Detailed view of the muscle
spindle apparatus showing type I and type II sensory fibers that are large, myelinated, and rapidly
conducting neurons that detect stretch. The γ motor neurons contract the spindle to keep it taut and
sensitive to further stretch, whereas the α motor neurons contract the muscle fibers. 17

18. You had gone to bed late after a
long busy day, and fell asleep
quickly. At 3 am you smell
smoke.
How is it that you are suddenly
wide awake, and getting
everyone out of the house
safely?
Describe the physiologic
responses at the moment.
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19. • Alpha motor neurons - lower motor
neurons (LMNs) from the spinal cord to
skeletal muscle fibers; increased firing of
alpha motor neurons causes muscle
contraction (and therefore, increased
muscle tone).
• Gamma motor neurons - specialized
motor neurons from the spinal cord to
the muscle spindles (3); increased firing
of gamma motor neurons causes muscle
spindles to be more skinny, thus
increasing the firing of muscle skinniness
receptors.
• Stretch reflex - Increased stretch of
muscle skinniness receptors (1) and thus
more firing of sensory nerves causes
reflex firing of alpha motor neurons (2)
and increases muscle tone.
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20. Increases firing
Of gamma neurons
Stress
Massage can
release
tension 20

21. Increased muscle
Tension through gamma
Neuron signaling from RAS
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22. Reflect
• Explain how can stress lead to a stiff neck.
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23. Draw secretion of cortisol
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Hint:

24. HPA Axis
Response to
Stressors –
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25. Normal Chronically High Cortisol
• Immune suppression
• Suppression inflammation
• Renal retention Na+ & water
• Renal excretion of K+
• Gluconeogenesis & Insulin
resistance
• Protein catabolism
• Fat redistribution
• Increased secretion gastric acid
• Calcium release from bones
• Multiple actions in the brain
• Increased infection risk
• Decreased wound healing
• ECV excess, edema
• Hypokalemia
• Increased blood sugar & cells
resistant to insulin
• Weaker muscles, wasting, thinning
skin
• Abdominal obesity, face, back neck
• GI distress
• Osteoporosis risk postmenopausal
women
• Impaired memory, mood swings!!
Actions of Cortisol
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26. Why can severe
childhood trauma
shut down growth?
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27. Capriotti, T., & Frizzell, J. P. (2016). Pathophysiology: Introductory concepts
and clinical perspectives. F.A. Davis Company.
Overview of effects of adrenal & SNS stimulation
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28. Patient/Family teaching with corticosteroids
• Look at the lists and discuss important teaching
• Compare and contrast the patient teaching about stress
management and corticosteroids. What do you notice?
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29. Patient/Family teaching with corticosteroids
Corticosteroids commonly given with brain surgery & other situations
to decrease inflammation; long term when immune suppression
needed (IBD)
• Infection prevention, risk wound infection
• Management of blood glucose
• Management of stomach acid
• Labile emotions common
• Body changes if long-term therapy
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30. Other responses to stressors, including
PAIN
•Increased ADH
•Increased aldosterone
•Increased growth hormone
•Stress response increases blood sugar
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31. Your patient is POD 2 from heart surgery.
Explain why the chart includes the following orders:
1. Giving insulin as indicated-why and why
2. Giving medicines to decrease stomach acid
3. Assessing and intervening to address constipation
4. Assessing and intervening to control elevated BP
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32. What are components of the stress response that we turn on
regardless if running from tiger, recovering from heart surgery,
stress about a new cancer diagnosis, or being unable to pay the
mortgage.
To run from the tiger:
1. Need energy to muscles that can help you escape
2. Deliver it as fast as possible to where needed-cardiovascular
3. Turn off long-term building projects (shut down digestion…)
a. Decrease saliva, shut down growth, don’t ovulate
4. Turn on attention to detail-alertness
Where is fear labeled in your brain?
Answer: amygdala. And remembered by the hippocampus
Neurons that fire together wire together-- these neurologic
connections are strengthened if fear is chronic (increasing risk
and consequences of stress).
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33. Why can persistent feelings
of being treated badly
lead to poor health?
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34. You are at the store shopping with your friend. You end
up in the slow check-out line. Your friend gets upset,
starts wild arm movements, asks the cashier in a loud
voice to speed up---you get the picture.
What is the concern with toxic hostility?
What is the benefit of using this time in the grocery
line to check out the latest issue of your favorite
magazine?
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35. Biological mechanisms
in HPA axis-induced
dysregulation in
response to toxic stress
Jiang et al., 2019, Epigenetic Modifications in Stress Response Genes
Associated with Childhood Trauma Frontiers in Psychiatry
https://doi.org/10.3389/fpsyt.2019.00808
Effect may be dose
dependent
Stress alters
expression of
multiple genes in HPA
axis, and can lead to
epigenetic changes
that are passed onto
offspring
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36. What helps you
decrease stress?
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37. As we move forward examining systems the rest
of this term and next term, this framework for
studying diseases may be helpful.
• What is the normal physiology?
• Causes of the disease (risk factors, etiology)?
• Physical problem (pathophysiology)?
• What general processes involved (inflammatory, immune, fluid
balances…)
• What are the person’s responses-signs/symptoms, emotional,
functional?
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38. Example applying framework with SIADH
• Normal: ADH released appropriately in response to increased serum
osmolality.
• Problem: brain tumor, trauma, infection or ectopic release of ADH-too
much ADH
• Physiology: hypothalamus/posterior pituitary. Problem or other
resulting in too much ADH. Causes kidney H2O retention, followed by
hyponatremia, cell swelling, LOC changes…
• General principle-fluid homeostasis
• Responses: lethargy, confusion. Decreased urine output. Person affected
may be reluctant with water restriction, so need to address emotional
need of a fluid/water restriction.
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39. Related resources
• How stress affects the brain:
• Madhumita Murgia 4:15
https://www.youtube.com/watch?v=WuyPuH9ojCE
• HPA-Cortisol-hippocampus effects
• Epigenetic change
• Exercise and meditation
• Mindfulness and Neural Integration-Ted Siegel 18:26
• TED talk-Hand Model
• https://www.youtube.com/watch?v=LiyaSr5aeho
• brain-mind-relationships
• Reflection; relationships; resilience
• Emotional and social intelligence-understanding feelings
• Compassionate (NVC) communication-Marshall
Rosenberg
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