Systems of the Body 2 and The Stress Process 1

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Systems of the Body 2 and The Stress Process 1

• September 7, 2004

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Overview

• Systems of the Body
• Digestive System
• Renal System
• Reproductive System
• Immune System
• Methodology
• The Stress Response

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The Digestive System

• Digestion the conversion process in which food
  is changed into a form which can be used by
  cells.
• Nutrients are supplied for growth and tissue
  repair.

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The Digestive System

• Bolus food lubricated by saliva and formed into
  a soft, rounded lump.
• Bolus passes through esophagus to stomach where
  gastric juices further the digestive process.
• Pancreas secretes juices into duodenum to break
  down proteins, carbohydrates and fats.
• Pancreas produces insulin to facilitate the entry
  of glucose into bodily tissues.
• Liver produces bile to break down fats.
• Absorption of food takes place primarily in the
  small intestine.
• Food residue passes into large intestine and then
  rectum.

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The Digestive System

• Disorders
• Gastroenteritis inflammation of the lining of
  the stomach and small intestine
• Diarrhea lining of the small and large
  intestine does not absorb water and digested food
• Dysentery
• Peptic Ulcer sore in the lining of the stomach
  or duodenum
• Gallstones stones in the gallbladder made of
  cholesterol, calcium, bilirubin, and inorganic
  salts
• Appendicitis accumulation of bacteria in the
  appendix
• Hepatitis a contagious disease causing the
  inflammation of the liver

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The Renal System

• Structures - kidneys, ureters, urinary bladder,
  and urethra
• Kidneys regulate bodily fluids, primarily they
  produce urine.
• Urine consists of surplus water, surplus
  electrolytes, waste products from metabolism of
  food, and surplus acids.
• Sodium and Potassium are key electrolytes.

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The Renal System

• Disorders
• Urinary tract infections can be caused by
  bacteria
• Acute glomerular nephritis inflammation of the
  glomeruli of the kidneys usually a secondary
  response to a Strep infection
• Tubular necrosis when cells in the tubules of
  the kidneys are destroyed then acute renal shut
  down can occur.

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The Reproductive System

• Each female has two ovaries, which produce
  estrogen and progesterone.
• One of the ovaries produces an ovum (egg) each
  month
• If the ovum isnt fertilized by a sperm then it
  is flushed out of the uterine cavity with the
  uterine endometrium and its blood vessels
  (menstruation)
• In males, the pituitary controls production of
  testosterone, which is produced by the
  interstitial cells of the testes.
• Testosterone brings about the production of sperm
  and the developing of male secondary sex
  characteristics.
• One sperm may fertilize the ovum, which then
  travels down the fallopian tube and embeds itself
  in the uterine wall.
• The implanted embryo will develop over nine
  months.

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The Reproductive System

• Disorders
• Sexually transmitted diseases - herpes,
  gonorrhea, syphilis, genital warts, Chlamydia,
  AIDS
• STDs may result chronic pelvic inflammatory
  disease in women.
• Reproductive system is vulnerable to testicular
  cancer and gynecologic cancers.
• 8 of U.S. couples have fertility problems

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The Reproductive System

• Genetics and Health
• Genetic material for inheritance lies in the
  nucleus of the cell in the form of 46
  chromosomes.
• Studies of genetically-related family members,
  twins, and adopted children are important in
  determining the etiology and genetic influences
  of diseases.
• Psychologists counsel couples regarding genetic
  testing and the psychosocial ramifications.

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The Immune System

• Infection - The invasion of microbes and their
  growth in the body.
• Four routes of infection
• Direct Transmission - contact
• Indirect Transmission environmental
  transmission
• Biological Transmission transmitting agent
  involved in the disease process infects a target
• Mechanical Transmission carrier transmits
  disease

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The Immune System

• The Course of Infection
• Incubation period
• Period of nonspecific symptoms
• Acute phase
• Fatality OR
• Period of decline during which invading organisms
  are expelled
• Infections may be localized, focal, or systemic.
  Primary infections may lead to secondary
  infections.

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The Immune System

• Immunity
• The bodys resistance to injury from invading
  organisms.
• Temporary natural immunity when breast fed.
• Natural immunity is acquired through disease.
• Artificial immunity vaccinations/inoculations
• The body has nonspecific and specific immune
  mechanisms.
• Nonspecific general responses to any type of
  infection or disorder
• Specific targeted to fight particular
  microorganisms

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The Immune System

• Disorders
• AIDS progressive impairment of immunity
• Cancer depends heavily on immunocompromise
• Autoimmunity a condition characterized by a
  specific humoral or cell-mediated immune response
  that attacks the bodys own tissues.
• Certain forms of arthritis
• Multiple sclerosis

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The Scientific Method
Normal Science Paradigm
Theory Based on observations
Hypothesis Predictions about what will happen
Data Collection
Accept or Reject Hypothesis
Analyze Data
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Methodology in Psychology

• Empiricism
• Measures observable phenomenon
• Theory Formulation and Hypotheses Testing
• Researchers observe every day phenomena.
• These observations form the basis of scientific
  theory and inquiry.

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Methodology
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Methodology

• Experiment
• A study where there is random assignment to
  treatment groups in an intervention focused on
  exercise and weight loss
• Correlation
• A study of the relationship between cultural
  identity and physical symptoms
• Prospective
• A study following the physical and mental health
  indicators outcomes of cancer patients 6 months,
  1 year, and 2 years after chemotherapy
• Retrospective
• A study examining the past coping strategies of
  cardiac patients

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Experimental Research

• Random assignment to conditions
• Manipulate independent variable to determine
  causality
• Test statistically for significant differences
  between groups
• Quasi-experimental methods When individuals
  cannot be randomly assigned to groups
• Definitions
• Independent Variable what the researcher
  manipulates
• Dependent Variable the outcome (what changes
  based on the manipulation of the independent
  variable)
• Internal Validity the degree to which the
  conditions of the experiment are causing the
  effect
• External Validity generalizabilty of results to
  other contexts
• Types
• Laboratory studies
• Clinical Trials
• Strengths Limitations
• Evidence for causation Generalizability
• Generalizability real world applications

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Experimental Research
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Correlational Research

• Systematically measures the relationship between
  variables
• Correlation coefficient values (r) between -1, 1
• Test for significant linear relationships between
  variables
• This will be affected by sample size
• In larger samples relationships may be
  significant with a relatively small r value.
• Types
• Surveys
• Randomly selected populations
• Strengths
• Real World Context
• May be most expedient method
• Limitations
• Correlation does not equal causation

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Prospective Research

• Prospective
• A study following the physical and mental health
  indicators outcomes of cancer patients 6 months,
  1 year, and 2 years after chemotherapy
• Type
• Self-report over time
• Strengths
• Can examine changes over time
• Relatively non-invasive
• Limitations
• Accuracy of self-report
• Many factors over time effect determination
  causality

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Retrospective Research

• Retrospective Research
• A study examining the past coping strategies of
  cardiac patients
• Type
• Self-report
• Retrospective recall
• Strengths
• Examines patterns of past behavior in the context
  of a specific event
• Limitations
• Accuracy of memory and self-report
• Limited determination of causality

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Stress

• A negative emotional experience accompanied by
  biochemical, physiological changes that are
  directed either toward altering the stressful
  event or accommodating to its effects (Baum,
  1990)
• Stressful events are called stressors
• Sitting in traffic
• Bad relationships
• Job interviews
• Death in the family
• Perception affects the degree of stress
  experienced.

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Stress
Personal Resources

• Sufficient to meet demands
• Low Stress
• Not sufficient to meet demands
• High Stress

Personal Resources
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Stress Fight or Flight Response (Cannon, 1932)

• When an organism perceives threat
• Sympathetic nervous system is aroused
• Endocrine system is aroused
• Organism is mobilized to attack the threat or to
  flee from the threat
• Adaptive allows quick response to threat
• Harmful unabated stress is harmful to the
  organism physically and psychologically

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Stress

• General Adaptation Syndrome (Selye, 1956)
• Nonspecific Response - The body responds to
  stress with the same physiological reactions

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Stress
Resistance
Normal level of Resistance
Alarm
Exhaustion
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Stress

• General Adaptation Syndrome (Selye, 1956)
• Three Phases in reacting to a stressor
• Alarm The bodys first reaction
• Resistance Occurs with continued exposure
• Exhaustion Physiological resources are depleted

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Stress

• General Adaptation Syndrome (Selye, 1956)
• Criticisms of the Model
• Limited role given to psychological factors
• Responses to stress are influenced by individual
  difference, perceptions, and preexisting physical
  and mental health
• Stress is assessed as an outcome

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Stress

• Cognitive (Psychological) Appraisal (Lazarus,
  1968 Lazarus Folkman, 1984)
• Two step process
• Primary appraisal process What is at stake in
  the stress situation?
• Is this event positive?
• Is this event neutral?
• Is this event negative?
• Has harm already been done?
• Is there a threat of future damage?
• How challenging is the event, that is, can I
  overcome it or even profit from it?

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Stress

• Secondary Appraisal What are my coping and
  psychological resources in this situation?
• How does the individual address the
• Harm
• Threat
• Challenge

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Stress

• Tend and Befriend (Taylor et al., 2000)
• Model of affiliative responses to stress
• The sympathetic arousal underlying
  fight-or-flight may be down-regulated in females
  leading to nurturing behavior
• Females responses to stress evolved to care for
  self and for offspring

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Stress

• Oxytocin may be significant in female responses
  to stress
• Animals and humans with high oxytocin levels are
  calmer, more relaxed, more social, and more
  maternal in behavior
• Females rely more on social networks during stress

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Physiology of Stress

• SAM Sympathetic adrenomedullary system
• Cannons Fight-or-Flight Response
• Sympathetic arousal stimulates the medulla of the
  adrenal glands to secrete catecholamines
  (epinephrine and norepinephrine)
• Blood pressure and heart rate increase,
  constriction of peripheral blood vessels,
  increased sweating

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Physiology of Stress

• HPA Hypothalamus-Pituitary-Adrenocoricotropic
• Selyes General Adaptation Syndrome
• Hypothalamus releases corticotrophin-releasing
  factor (CRF) which stimulates the pituitary gland
  to release ACTH (adrenocorticotropic hormone)
• ACTH stimulates the adrenal cortex to release
  glucocorticoids, especially cortisol
• Review figure 6.3

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Physiology of Stress

• Effects of Long-Term Stress
• Physiological changes are designed for fight of
  flight (short-term mobilization)
• Long-term exposure to stress can have detrimental
  physical consequences.
• Evidence supports that HPA activation may be more
  significant than SAM activation when individuals
  are under long-term stress.
• Corticosteroids have immunosuppressive effects
• Prolonged cortisol secretion is related to
  destruction of neurons in the hippocampus.

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Assessing Stress

• Self-reports of perceived stress
• Self-reports of life changes
• Behavioral measures, such as task performance,
  under stress
• Physiological measures, such as skin
  conductivity, heart rate, and blood pressure
• Biochemical markers, such as elevated cortisol
  levels

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Dimensions of Stressful Events

• Negative events are more likely to produce stress
  than are positive events.
• However, people who hold negative views of
  themselves, positive life events appear to have a
  detrimental effect on health
• Positive life events are linked to better health
  in people with high self-esteem
• Uncontrollable, unpredictable life events are
  most stressful
• Ambiguous events are more stressful

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Dimensions of Stressful Events

• Overloaded people are more stressed than are
  people with fewer tasks to perform
• More vulnerability to stress occurs in central
  life domains than in ones peripheral life
  domains
• The most important aspects of an individuals
  life are more vulnerable to stress