Immunity and Healing: Understanding the Immune System and its Processes

1. Chapter 12: Immunity and Healing

2. Introduction • Pathogens: disease-causing agents • Immunity: protection from or resistance to infection and disease • Immune system: group of organs and tissues throughout body • Immunity and healing processes profoundly affected by stress, emotions, beliefs, and attitudes

3. Organs and Tissues of Immune System • Not physically connected, but scattered throughout body • Some structural components of cardiovascular, lymphatic, and endocrine systems • 2 broad groups: • Primary lymphoid organs and tissues where lymphocytes are produced • Secondary lymphoid organs and tissues: sites where most immune responses occur

4. Organs and Tissues of Immune System

5. Primary Lymphoid Organs and Tissues • Organs and tissues that produce lymphocytes: • Red bone marrow • Thymus • Lymphocytes target specific pathogens • 2 types of lymphocytes: • B cells • T cells

6. Secondary Lymphoid Organs and Tissues • Sites where most specific immune responses occur • Mucosa-associated lymphoid tissue (MALT): • Lymph nodes • Spleen • Tonsils (see Figure 12-3) • Peyer patches • Manual therapy contraindicated with enlarged spleen or severe infection

7. Pathology Alert: Tonsillitis • Inflammation of tonsils • Viral or bacterial infection • Common signs and symptoms: • Red, swollen tonsils, may have white patches • Sore throat, pain or difficulty swallowing • Headache, fever, and chills • Manual therapy contraindicated

8. Nonspecific Immune Defenses • Generic and universal immune responses • Also called innate immune defenses • Responses not stimulated by or directed toward single type of pathogen or foreign invader • Include physical and chemical barriers

9. Physical Barriers • Physical barriers: • Epidermis of skin • Mucous membranes lining respiratory, digestive, and reproductive tracts • Barriers that physically block microbes from entering body • If barrier is broken, pathogens can enter

10. Chemical Barriers • Sebum: protective acidic barrier on skin surface • Sweat: enzymes and pH discourage microbial growth • Tears, saliva: wash away microbes, contains antimicrobial protein lysozyme • Gastric juice: destroys pathogens that reach stomach • Urine: flushes urethra, pH inhibits microbial growth • Vaginal secretions: flushes vagina, acidic pH inhibits bacterial growth

11. Internal Antimicrobial Proteins • Interferons: protect surrounding uninfected cells from viral infection • Complement proteins: support phagocytosis, microbe destruction, inflammation • Transferrins: bind with iron to inhibit bacterial growth • Antimicrobial peptides: cause cytolysis of microbes

12. Phagocytes and Natural Killer Cells • Neutrophils and macrophages • Eat microbes and cellular debris • Phagocytosis (see Figure 12-4) • NK cells • Lymphocytes found in blood • Kill infected cells through cytolysis

13. Inflammation and Fever • Inflammation • Fights infectious agents by increasing vasodilation, capillary permeability, and phagocytosis • Prepares tissue for repair • Fever • Speeds up metabolism to facilitate tissue repair • Kills or inhibits growth of certain bacteria • Increases effect of interferons

14. Pathology Alert: Allergies • Allergic reaction: excessive immune response to an antigen (allergen) • Allergens can be inhaled, ingested, injected, implanted, or contact skin • Reaction marked by massive histamine and heparin release with several physiological effects • Most allergic responses localized • Anaphylaxis: widespread response, can be fatal • Manual therapists: avoid substances that may stimulate allergic response

15. Antibody-Mediated Immune Responses • Specific immune responses: • Triggered by specific pathogens • B and T lymphocytes • Create immunological memory • Antibody-mediated immunity (humoral immunity) • Activation of B lymphocytes to produce antibodies that render antigens harmless • See Figure 12-5

16. Pathology Alert: Autoimmune Disease • Autoimmune disorder or disease: immune system attacks person’s own cells • Common autoimmune disorders: • Multiple sclerosis (MS), rheumatic fever, rheumatoid arthritis • Systemic lupus erythematosus, scleroderma, ulcerative colitis, type 1 diabetes, myasthenia gravis • Exact causes not well understood

17. Cell-Mediated Immune Responses • Cell-mediated immunity (see Figure 12-6) • Activates several categories of T lymphocytes • Cytotoxic T cells that directly destroy the antigen • Memory T cells “remember” particular antigen • Helper T cells, suppressor T cells • Manual therapy: precautions for immune-compromised clients • Vaccinations recommended for manual therapists

18. Acquisition of Immunity • Immunological memory • Memory cells produced with each episode of specific immune response • Accounts for how individuals acquire immunity to many diseases • Immunity acquired naturally or artificially • Both have active and passive mechanisms

19. Naturally Acquired Immunity • Naturally acquired active immunity • Exposure to antigen initiates specific response resulting in formation of cells • Once recovered, body retains resistance through immunological memory • Naturally acquired passive immunity • Antibody transfer from mother to baby across placenta and through breast-feeding

20. Artificially Acquired Immunity • Artificially acquired active immunity • Vaccination delivers dead or altered pathogens or synthesized antigens • Results in formation of antibodies and long-lasting resistance through immunological memory • Artificially acquired passive immunity • Immunization delivers antibodies - immediate but short-term immunity

21. Aging and the Immune System • Immune defenses generally decline with age • Less responsive • Slower response • Decreasing T and NK cells • Less responsive to vaccinations • Incidence of cancer and autoimmune disorders increases

22. Psychoneuroimmunology • PNI:the study of links among nervous, endocrine, digestive, and immune systems • Research supports mind–body connection • 2 body-wide communication networks: • Autonomic nervous system • Vast chemical network of “information molecules”

23. Peptide Communication Network • Peptides travel throughout body • Hundreds of chemicals communicate and stimulate cells • Collectively called ligands • Communication web of peptides and receptors: • Strong functional link between immune responses and emotional states • Mind–body–spirit connection

24. Holistic Healing • Disease: any disruption to dynamic balance of body, mind, and spirit causing physical, mental, or emotional trauma • Clients’ belief in value manual therapy can have powerful benefits even when not explained by medical science • Some benefits of manual therapy subjective and difficult to measure