ch. 9 stress and disease

what does adrenocorticotropic hormone (ACTH) do?

ACTH is released into the bloodstream where it travels to the adrenal glands -ACTH binds to specific receptors in the adrenal cortex -This stimulates the adrenal cortex to release cortisol into the blood

what occurs in allostasis?

Adaptive process that maintains homeostasis through production of adrenalin, cortisol and other chemical messengers. Promote adaptation after acute stress But can also contribute to allostatic overload.

Physiologic stress: Selye

Adrenal glands enlarge Lymphocytes decrease Ulcers develop

Define the HPA Axis

Adrenaline is delivered into your neurobiological system by what is known as the hypothalamic-pituitary-adrenal axis, or the HPA axis. -named after three components: the hypothalamus, the pituitary gland, and the adrenal glands. The hypothalamus is the master regulator of the body and brain and is considered the control center for the body's autonomic responses. It is located in the center of the brain. If it becomes excited, it releases corticotropin-releasing hormone (CRH) to activate the pituitary gland.

define allostatic load

Allostatic load is the individualized cumulative amounts of stressors that exist and that influence physiologic responses. Allostatic load includes genetic makeup, lifestyle including damaging health behaviors, daily events, and sometimes dramatic events such as disasters.

Define allostatic overload

Allostatic overload is an exaggerated pathophysiological response to stress.

what does norepi primarily affect?

alpha receptors

adrenal medulla

releases catecholamines (epi and norepi)

Describe the 3 stages of the GAS

1st stage is the alarm stage, which provides a burst of energy. 2nd stage, is the resistance stage, the body attempts to resist or adapt to the stressor. 3rd stage is known as the exhaustion stage because energy is depleted.

Stress Response 1st Stage

1st- your brain has to recognize that there is a problem. The hypothalamus is triggered by the Amygdala - the emotional processing of the brain. The hypothalamus is connected to the ANS ( SNS & PNS). Adrenal glands now stimulated to secrete adrenaline ( Epi and norepi). Increased HR, BP, resps, bronchodilation, O2 to brain, increased vision and senses, blood flow to heart & muscles & organs, triggers release of blood sugar.

HPA Axis of Stress Response

CRH - Corticotropin Releasing Hormone's main function is the stimulation of the pituitary synthesis of ACTH, as part of the HPA Axis. ACTH is an important component of the hypothalamic-pituitary-adrenal axis. Produced in response to biological stress (along with its precursor corticotropin-releasing hormone from the hypothalamus). Its principal effects are increased production and release of cortisol by the cortex of the adrenal gland

what does corticotropic releasing hormone do?

CRH travels in the blood and binds to specific receptors in the pituitary gland -This binding causes increased production of adrenocorticotropic hormone (ACTH)

what does cortisol do?

Cortisol enables the body to cope with stress in a more effective manner -Increased levels of cortisol also have an immunosuppressive effect Increased serum cortisol inhibits production of CRH and ACTH via negative feedback

Glucocorticoids and catecholamines

Decrease innate immunity (inflammatory response) while increasing adaptive immunity (Thelper cells) Increased during acute inflammation Anti-inflammatory effects Immunosuppresses the body

Psychoneuroimmunologic Regulation

Diseases result from relationships among: Consciousness CNS Immune system

Physical Effects of Stress: cardiac

HTN CAD ( remember that the coronary arteries feed the heart). The heart is a working pump. Remember Cardiac Ouput

What interventions or prevention activities reduce stress-related diseases?

Identify effective coping strategies Accept that there are events that you cannot control. Learn and practice relaxation techniques; try meditation, yoga, or tai-chi for stress management. Exercise regularly. Your body can fight stress better when it is fit. Eat healthy, well-balanced meals. Learn to manage your time more effectively. Set limits appropriately and learn to say no to requests that would create excessive stress in your life. Make time for hobbies, interests, and relaxation and social connections. Get enough rest and sleep. Your body needs time to recover from stressful events. Don't rely on alcohol, drugs, or compulsive behaviors to reduce stress. Seek out social support. Spend enough time with those you enjoy. Seek treatment with a psychologist or other mental health professional trained in stress management

what happens chemically in stage 1?

Increased secretion of glucocorticoids ( cortisol) by the adrenal cortex. Increased secretion of epi and norepi from the adrenal medulla.

Define psychoneuroimmunology

Interactions of consciousness, the brain and spinal cord, and the body's defense mechanisms Immune modulation from the psychosocial stressors or interventions leads directly to health outcomes Corticotropin-releasing hormone (CRH) is released from the hypothalamus

allostasis

Key physiologic systems involved Proinflammatory Cytokines Decline in PNS Cortisol Catecholamines of the SNS Epi and Nor Epi

examples of antagonists

Metoptrolol - selective B1 Carvedilol - selective alpha 1 and nonselective beta Prazosin - selective A1

reasons for stress: emotional

Perception of past trauma, work, etc...

Growth hormone (somatotropin)

Produced by the anterior pituitary and by lymphocytes and mononuclear phagocytic cells Metabolic affects - affects protein, lipid, and carbohydrate metabolism and counters the effects of insulin Enhances immune function Chronic stress decreases growth hormone

oxytocin

Produced by the hypothalamus during childbirth and lactation Produced during orgasm in both sexes May promote reduced anxiety

reactive response

Psychological response causing reactive physical (somatic) symptoms

conditional response

Response to specific stimuli/situation

stage 1: alarm phase

SNS Secretion of catecholamines and hormones to support physiological and metabolic activity. Boosts the immune system Increased physical strength and mental activity. Elevated BP Elevated glucose Increased blood supply to muscles. It is an automatic and instantaneous response that increases the body's capability to cope.

ANS equals:

SNS + PSNS

immune

The inflammation causes the body to attack the good things. Body suppresses the immune system - delayed wound healing.

what does epi activate

alpha and beta receptors

Selective beta blockers (metoprolol) versus nonselective beta blockers (carvedilolol) also affects:

alpha receptors

what does the sympathetic nervous system release?

catecholamines also increases proinflammatory cytokine which in turn is an agonist to inflammatory response

somatic nervous system

causes voluntary movements due to a stressor (stimulus)

how does your brain participate in allostasis?

constantly monitoring for parameters to anticipate. Contributions from the neuroendocrine and ANS. Highly individualized Brain is the key player in perceiving stress.

sleep depravation/ OSA

elevated cortisol, decreased concentration, elevated insulin and glucose levels, elevated BP, increased proinflammatory cytokines, increased hormone ghrelin ( by cells of stomach and pancreas) which increases appetite

cortisol for stress:

exogenous - methylprednisolone succinate, prednisone - MOA - controls or prevents inflammation modulates metabolism and homeostasis metabolized by liver eliminated by renal system

What happens when the GH is suppressed?

immunity is decreased which will increase one's chance of becoming ill.

what does somastatin do?

inhibits somatoropin

What are catecholamines?

neurotransmitters when they are produced in the sympathetic nervous system and brain and circulating hormones when synthesized in the adrenal medulla. The endogenous catecholamines include dopamine, epinephrine, and norepinephrine

if you give them alpha/beta adrenergic blockers, what happens?

pressure drops, breathe better, decrease workload on the heart, etc....think of adrenergic antagonists as a down regulator of the catecholamines

what are cytokines?

regulators of host responses to infection, immune responses, inflammation, and trauma. Some cytokines act to make disease worse (proinflammatory), whereas others serve to reduce inflammation and promote healing (anti-inflammatory). Excreted from immune cells like helper T cells and macrophages, and certain other cell types that promote inflammation.

what initiates anxiety and panic attacks?

the amygdala senses environmental stressors that stimulate fight or flight response. The amygdala is directly associated with conditioned fear.

Those with autoimmune dz are more prone to infection because:

the relationship of glucocorticoids and catecholamines

adrenal medulla: catecholamines part 2

β-adrenergic receptors β1 (heart) and β2 (vascular and nonvascular smooth; i.e., lungs) Mimic direct sympathetic stimulation (fight/flight)

stress is directly r/t:

*proinflammatory cytokines* Linkages between stress, immune function, and disease Immune system affected by neuroendocrine factors Stress response decreases T cell cytotoxicity and B cell function Stress releases cortisol which is an antiinflammatory

The Stress Response- Regulation of the Hypothalamic-Pituitary-Adrenal System (HPA)

-Corticotropic releasing hormone (CRH) is secreted from the hypothalamus -This release is influenced by stress levels, time of day and serum cortisol levels -CRH travels in the blood and binds to specific receptors in the pituitary gland -This binding causes increased production of adrenocorticotropic hormone (ACTH) -ACTH is released into the bloodstream where it travels to the adrenal glands -ACTH binds to specific receptors in the adrenal cortex -This stimulates the adrenal cortex to release cortisol into the blood -Cortisol enables the body to cope with stress in a more effective manner -Increased levels of cortisol also have an immunosuppressive effect -Blood glucose is also increased via breakdown of glycogen, protein and fat -Increased serum cortisol inhibits production of CRH and ACTH via negative feedback

How does the immune system participate in stress-related diseases?

-The stress hormone corticosteroid can suppress the effectiveness of the immune system (e.g. lowers the number of lymphocytes) -Stress can also have an indirect effect on the immune system as a person may use unhealthy behavioral coping strategies to reduce their stress, such as drinking and smoking , poor diet due to lack of time, lack of exercise for the same reason, lack of sleep etc. -Stress is linked to: headaches; infectious illness ; cardiovascular disease; diabetes, asthma and gastric ulcers.

physiologic stress

1.) Enlargement of adrenal gland 2.) Decreased lymphocyte levels 3.) Development of bleeding ulcers These physiologic stressors impair the ability of the body to resist future stressors. Represent the hallmark patterns of a nonspecific stress response - GAS

Why do stress related diseases occur?

-raises catecholamine and suppressor T cells levels, which suppress the immune system. This suppression, in turn raises the risk of viral infection. -Stress also leads to the release of histamine, which can trigger severe broncho-constriction in asthmatics. -Stress increases the risk for diabetes mellitus, especially in overweight individuals, since psychological stress alters insulin needs. Stress also alters the acid concentration in the stomach, which can lead to peptic ulcers, stress ulcers or ulcerative colitis. -Chronic stress can also lead to plaque buildup in the arteries (atherosclerosis), especially if combined with a high-fat diet and sedentary living. -The correlation between stressful life events and psychiatric illness is stronger than the correlation with medical or physical illness.

Cortisol (glucoCORTicoids/hydroCORTisone)

Activated by adrenocorticotropic hormone (ACTH) Promotes cellular metabolism Promote metabolic syndrome Insulin resistance obesity Stimulates gluconeogenesis Elevates the blood glucose level by other hormone (glucagon, epi, GH) Inhibits the uptake and oxidation of glucose Powerful anti-inflammatory and immunosuppressive agent

examples of agonists

Albuterol - selective B2 Clonidine - selective A2 Dobutamine - selective B1

Stage 2: Resistance Stage- The body is trying to fix what is causing the stress.

During this stage the body has increased capacity to respond to the stressor. Due to high energetic costs, the body cannot maintain high levels of resistance to stress forever, and if the stressor persists the body may advance into exhaustion. If it were something like blood loss, then the hypothalamus would be telling the kidneys to take H20 from the urine an put it back into the blood to maintain volume by releasing ADH ( antidiuretic hormone). This requires continued mobilization of the body's resources to cope.

metabolism

Excess glucose increases blood sugar. Increased BS causes CAD

3 components of physiologic stress

Exogenous/endogenous stressor initiating the disturbance Chemical/physical disturbance produced by the stressor Body's adaption or lack of to stressors

Psychologic distress

General state of unpleasant arousal after life events that manifests as physiologic, emotional, cognitive, and behavior changes

Stress Response H-P-A axis

Nervous system Endocrine system Immune system Stress response causes the nervous and the endocrine system to become activated having an effect to our immune system.

anticipatory response

Physical s/s due to the anticipation of what is about to occur

reasons for stress: chemical

Poor Sleep Toxic Food Medication Environmental

adrenal medulla: catecholamines

Released from adrenal medulla Epinephrine (80%) and norepinephrine (20%) released α-adrenergic receptors α1 and α2

prolactin

Released from the anterior pituitary Necessary for lactation and breast development Released during stressful stimuli

endorphins

Released in response to stressor Inflamed tissue activates endorphin receptors Proteins found in the brain that have pain-relieving capabilities

allostatic overload

Represents the body's physiologic and immune system inability to no longer cope with the stressors Marks the onset of disease

testosterone

Secreted by Leydig cells in testes Regulates male secondary sex characteristics and libido ____ levels decrease because during stressful stimuli Exhibits immunosuppressive activity

what is the parasympathetic nervous system activated for?

balance sympathetic nervous system and generally opposes (antagonizes) the sympathetic nervous system, including the inflammatory response; hence both SNS and PNS affect the body's immune system. If the body is overwhelmed, the parasympathetic nervous system will not be able to balance the body resulting in the body being exposed for prolonged periods to inflammation leading to disease.

How is stress r/t unhealthy coping behaviors

When people are under chronic stress, they tend to smoke, drink, use drugs and overeat to help cope with stress. These behaviors trigger a biological cascade that helps prevent depression contribute to a host of physical problems that eventually contribute to early death. People engage in bad habits for functional reasons, not because of weak character or ignorance,

reasons for stress: physical

Work School Past Trauma Injury DZ

physiologic stress involves:

alteration and adaption of 3 components Stress can be from chemical or physical change ( Physiological stress can be in response to external environment or within the body itself

stress processes are:

bidirectional: from brain to body and body to brain ( ANS, immune, neural and endocrine). They can be protective promoting short term adaptation ( allostasis). Chronic stress lead to long-term dysregulation leading to stress induced dz states ( allostatic overload).

More exposure to proinflammatory cytokines, higher the chronic inflammation results in?

certain disease processes: COPD, DM, osteoporosis, arthritis, CV, ASCVD, CAD, cancers, dz associated with aging, etc.

what is the stress response?

the body's rxn to anything that throws if off balance internally. ( Injury, infection, fear, exercise, pain). The body reacts with the Alarm Phase which can progress to the Resistance Phase, where the body tries to fix the problem. If it fails, it progresses to the exhaustion phase.

stage 3: exhaustion phase- allostatic overload

the cost of chronic exposure to elevated or fluctuating endocrine or neural responses resulting from chronic or repeated challenges that the individual experiences as stressful

how does the brain respond to acute and chronic stress?

the hippocampus, amygdala, and prefrontal cortex can undergo remodeling that alters behavioral and physiological responses to increase the risk of developing cognitive impairment and depression.

Immune-mediated disease results from:

the interrelationships of the psychosocial, emotional, genetic, neurologic, endocrine, and immune systems and behavioral factors