Ch. 11 - Stress Response Flashcards
Define Stress. Identify the systems of the body that respond to stress and the types of stress these systems respond to.
Stress is when a demand or demands exceed the body’s ability to cope
–> Leads to compromised cognition, emotion, behavioral, and physical disturbances
Systems of the body that respond to stress:
1. Sympathetic - fight or flight
2 CRH hormonal axis (HPA Axis) of control from the hypothalamus, pituitary, and adrenal gland
Types of stressors:
a) Emotional - school exams, death of a loved one, divorce, financial, legal
b) Anticipatory response - fear, anxiety
c) Conditioned response - through experience, anticipated danger (fear, anxiety, depression)
d) PTSD - traumatic events cause sleeplessness, depression, and flashbacks
e) Physical - injury, surgery, physical exercise, infections, excessive sunlight, obesity
f) Environmental - heat, cold, infections, noise, pain, malnutrition, prolonged exertion, radiation, anxiety, depression, anger, drugs, surgery
REGARDLESS TO THE KINDS OF STRESS, THE BODY RESPONDS TO ALL STRESSORS IN THE SAME PHYSIOLOGICAL WAY
*** Stressors are accumulative, many small stressors may trigger a major physiological response
Name and define the Three stages of stress adaptation identified by Selye et.al. In the General Adaptation Syndrome, (GAS) Be prepared to list the neurological, hormonal, and physiological steps that lead to each of these stages.
- Alarm Stage - CNS is aroused and bodies defenses are aroused (fight or flight) Primarily a sympathetic response
–> Epinephrine and Norepinephrine
- Resistance and Adaptation Stage - Longer term physiological changes. Sympathetic and Cortisol
–> Adaptive is especially a cortisol response
- Exhaustion Stage - leads to breakdown of compensatory mechanisms –> can lead to failure of immune response, heart failure, renal failure, and death
Identify all of the effects and side effects of the sympathetic nervous system’s response to short term and long term stress listed on the table on page 340. Be prepared to discuss the physiological and medical implications of each for short term and long term exposure to stress.
SNS takes over and Parasympathetic backs up off during stress response
CNS effects: increased arousal, vigilance, and anxiety, protective emotions
- Up/Down regulation of the immune system
- Increased Blood Pressure due to
a) stimulation of alpha receptors in vascular smooth mm
b) Increased CO through stimulation of B1 receptors –> increased HR, increased strength of contraction - Decreased Gastric Secretion –> decreased stimulation of muscarinic receptor
- Increased glycogenolysis –> epinephrine inhibiting insulin secretion and direct epinephrine stimulation of glycolysis
- Increased blood glucose
a) epinephrine stimulation of B2 receptors on liver to increase gluconeogenesis
b) decrease glucose uptake by skeletal mm. result of decreased insulin from epinephrine as well as epinephrine effect on skeletal mm. - Increased circulating FFA –> increased lipolysis through beta 3 receptors (epinephrine on adipose cells)
- decrease glucose uptake –> decreased insulin release through epinephrine stimulating a2 receptors on Pancreatic B cells causes peripheral tissues to decrease glucose uptake
Identify all of the effects and side effects of the Hypothalamus, Pituitary, Adrenal axis (CRH, ACTH, cortisol) in response to short term and long term stress listed on the table on page 341. Be prepared to discuss the physiological and medical implications of each for short term and long term exposure to stress.
Stimulated through the CRH (HPA Axis) of control or ATCH axis of control
- Liver
- -> Increased protein synthesis and RNA synthesis
- -> Increased gluconeogenesis, increased glucose secretion into the blood
- -> increased blood glucose, increased clotting factors/complement - Protein catabolism: in mm., lymphoid tissue, bone, and skin
- -> increased blood AA levels - Anti-inflammatory:
- -> decreased circulating monocytes and macrophages
- -> decreased lymphocytes and eosinophils
- -> decreased kinins, prostaglandins, histamines released from leukocytes - Immunosuppression:
- -> atrophy of lymphoid tissues due to protein synthesis
- -> lower levels of cortisol stimulate humoral immunity but block cell mediated immunity
- -> Th1 suppression causes Th2 shift
- -> high doses decreases production of antibodies due to protein catabolism of lymphoid tissues. SUPPRESSES BOTH HUMORAL AND CELL MEDIATED IMMUNE SYSTEM - Lipolysis in extremities
- Lipogenesis in neck and trunk (Cushing’s Syndrome)
- Inhibits fibroblast proliferation –> decreased wound healing
- Results in polycythemia –> increased RBC synthesis
- Decreased secretion of testosterone, decreased libido
- -> thought to be related to increased cortisol levels inhibiting LH in males - Inhibition of GnRH, LH, and FSH
- Promotes gastric secretion, pepsin and HCl
- Simulates osteoclasts = osteoporosis
Identify when these two systems have complimentary effects and antagonistic effects and their short and long term implications
Complimentary Effects:
–> Increased Gluconeogenesis (both simulate liver to produce glucose)
–> up and down regulation of immune system (slight difference in that cortisol can completely shut it off)
–> lipolysis occuring
–> NE and Cortisol shut down Th1 cells but enhance Th2
Antagonistic Effects:
- -> SNS have decreased Gastric Secretion
- -> Cortisol promotes Gastric Secretion
- -> SNS causes you to lose weight everywhere
- -> Cortisol causes you to only lose weight in extremities but not in trunk
- -> Epi enhances Th1 but doesn’t do anything to Th2
Briefly discuss the role of each of the following in the stress response. Prepare to discuss the stimulus for release of each and their effects: Be able to discuss their short term benefits and long term detriments in terms of body metabolism and immune response.
B endorphins
B endorphins are released by the pituitary and some immune cells to act as an endogenous pain killer.
Gives sense of well-being and euphoria.
–> Binds to opiate receptors
Briefly discuss the role of each of the following in the stress response. Prepare to discuss the stimulus for release of each and their effects: Be able to discuss their short term benefits and long term detriments in terms of body metabolism and immune response.
Aldosterone
Aldosterone is stimulated by ACTH axis of control to some degree.
Causes reabsorption of Na+ and Water. Increases blood fluid volume and increases blood pressure.
Released from adrenal cortex on top of kidneys.
Briefly discuss the role of each of the following in the stress response. Prepare to discuss the stimulus for release of each and their effects: Be able to discuss their short term benefits and long term detriments in terms of body metabolism and immune response.
Prolactin
Prolactin acts as a second messenger for IL-2 and has a positive effect on B lymphocytes activation and proliferation.
Briefly discuss the role of each of the following in the stress response. Prepare to discuss the stimulus for release of each and their effects: Be able to discuss their short term benefits and long term detriments in terms of body metabolism and immune response.
Growth Hormone
Prolonged stress response will inhibit secretion of Somatotropin (GH receptors are present on lymphocytes)
Somatotropin = GH
–> promotes growth, cell proliferation, and cell reproduction/ regeneration
Briefly discuss the role of each of the following in the stress response. Prepare to discuss the stimulus for release of each and their effects: Be able to discuss their short term benefits and long term detriments in terms of body metabolism and immune response.
ADH (Vasopressin)
Posterior pituitary response
–> increased secretion of ADH causes increased reabsorption of pure water thus increasing BP
Briefly discuss the role of each of the following in the stress response. Prepare to discuss the stimulus for release of each and their effects: Be able to discuss their short term benefits and long term detriments in terms of body metabolism and immune response.
Estrogen
Estrogen is inhibited during cortisol release because it blocks FSH and LH
Person will have amenorrhea
–> supposed to have calming affect during stress response
Briefly discuss the role of each of the following in the stress response. Prepare to discuss the stimulus for release of each and their effects: Be able to discuss their short term benefits and long term detriments in terms of body metabolism and immune response.
Testosterone
Testosterone is decreased in its secretion due to the belief that cortisol inhibits LH
–> person will have decreased libido
Describe the direct effects of norepinephrine, epinephrine and cortisol on Th1 and Th2lymphocytes and explain the implications of these effects on the immune response as a whole.
NE and Cortisol –> inhibit Th1 but enhance Th2
HOWEVER if cortisol levels increase, then Th2 is also suppressed
Epinephrine on the other hand stimulated Th1 but has no effect on Th2
*Scary that if cortisol gets high enough your immune system is completely shut down!!!
