Pathophysiology Immunity, Inflammation & Healing PDF

Sultan Qaboos University College of Nursing 2024-2025, Fall Semester Pathophysiology Pathophysiology Immunity, Inflammation & Healing Dr. Jos...

Sultan Qaboos University College of Nursing 2024-2025, Fall Semester Pathophysiology Pathophysiology Immunity, Inflammation & Healing Dr. Joshua Muliira RN, DNP, CNE Associate Professor  Objectives By the end of this class, you are expected to: 1. Differentiate between lines of immune defenses. 2. Describe the main components of innate immunity. 3. Describe the steps of the inflammatory process. Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. 2  The Immune Response ‚ It defends the body against bacteria, viruses, abnormal cells (cancer cells), and other foreign substances it encounters. Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. 3  Review of Body Defenses Ex ‚ First line of defense nails  Nonspecific  Mechanical barrier  Unbroken skin and mucous membranes  Secretions such as tears and gastric juices Tysosome ‚ Second line of defense  Nonspecific  Phagocytosis Ex neutrophils  Inflammation monocytes ‚ Third line of defense have memory  Specific defense  Production of specific antibodies or cell-mediated immunity Btfor specific diseaseExpp infeluensa Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. 4 Defense Mechanisms in the Body Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. 5 Innate and Adaptive Immune Defenses ‚ There are two types of immune defenses: innate immunity (early reaction) and adaptive immunity (later responses). ‚ As a first line of defense, the innate immune system can distinguish self from oneself cells but is unable to distinguish between pathogens ‚ Adaptive or specific immunity (2nd line) responds less rapidly but more efficiently through focused recognition and amplified response to each unique type of foreign agent and also by enhancing the antimicrobial defenses of innate immunity. Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. 6  Innate Immunity ‚ Consists of cellular and biochemical defenses that are in place before infection and respond rapidly ‚ They normally respond only to microbes ‚ Major components of innate immunity include: 1. The epithelial barriers: which block the entry of infectious agents by preventing pathogen adherence and secrete antimicrobial enzymes 2. Phagocytic cells (mainly neutrophils and macrophages) engulf and digest microbes of different types. 3. Natural killer (NK) cells which kill foreign cells (certain pathogens) 4. Cell messengers (Cytokines) which regulate and coordinate many of the activities of cells of innate immunity and influence adaptive responses Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. 7  Adaptive Immunity ‚ Refers to immunity that is acquired through previous exposure to infection and other foreign bodies ‚ Can recognize and react to a large number of microbes and nonmicrobial substances, so it can distinguish between self and oneself ‚ The components of this system are white blood cells (T and B lymphocytes) and their products ‚ There are two types of adaptive responses: Humoral and Cell-mediated immunity that function to eliminate different types of microbes Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. 8  Humoral Immunity ‚ Is mediated by B lymphocytes (B cells) and is the principal defense against extracellular antigens and their toxins. Produced by T ‚ B cells differentiate into antibody-secreting plasma cells ‚ The circulating antibodies then interact with and destroy the microbes that present in the blood or mucosal surfaces Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. 9  Cell-mediated Immunity ‚ Is mediated by cytotoxic T-lymphocytes (T- cells) and functions in the elimination of intracellular pathogens (e.g., viruses) ‚ T cells develop receptors to recognize the viral peptides on the surface of the infected cells and signal to destroy this infected cell Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. 10 Defense Mechanisms in the Body Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. 11  Cell-mediated Immunity ‚ T lymphocyte cells complete their maturation in the thymus and function in the peripheral tissue to produce cell-mediated immunity and aid in antibody production. They differentiate into regulatory (helper T cells) and effector (cytotoxic T cells). ‚ The regulatory CD4+ helper T cells serve as a trigger for the immune response and are essential to the differentiation of T and B cells into antibody-producing plasma cells and the differentiation of T cells into effector CD8+ cytotoxic T cells that eliminate intracellular microbes PAIN patients don't when the body get infection for the second time have T helper T helper Dy will regulate the deffince Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. 12  Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. 13  Normal Capillary Exchange ‚ Generally, not all capillaries in a particular capillary bed are open.  Depend on the metabolic needs of the cells or the need for the removal of wastes ‚ Movement of fluid, electrolytes, oxygen, and nutrients in the arterial end based on net hydrostatic pressure ‚ Venous end—osmotic pressure will facilitate the movement of fluid, carbon dioxide, and other wastes. Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. 14 Review of Normal Capillary Exchange Precapillary sphincters restrict blood flow through some channels. Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. 15  Review of Normal Capillary Exchange Precapillary sphincters restrict blood flow through some channels. fromcapillaries to cell p Hydrostatic pressure moves fluid, electrolytes, oxygen, and nutrients out of the capillary at the arteriolar end Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. 16 Review of Normal Capillary Exchange Precapillary sphincters restrict blood flow through some channels. Hydrostatic pressure moves fluid, electrolytes, oxygen, and nutrients out of the capillary at the arteriolar end Osmotic pressure in the vessels moves of fluid, carbon dioxide, and other wastes into the blood at the venous end. Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. 17 Inflammatory Response Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. 18 diapedesis  WBCs up my capp do Physiology of Inflammation ‚ A protective mechanism and important basic concept in pathophysiology ‚ Disorders are named using the ending –itis. ‚ Inflammation is a normal defense mechanism ‚ Signs & symptoms serve as warning for a problem:  The problem may be hidden within the body. ‚ It is not the same as infection.  Infection, however, is one cause of inflammation. Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. 19  Inflammation ‚ Inflammation is the reaction of vascularized tissues to injury. ‚ Another definition is “Inflammation is the body’s non- specific response to injury” ‚ It was described in terms of cardinal signs of inflammation. ‚ The signs are redness, swelling, heat, and pain. Later, a fifth cardinal sign was added, which is loss of function. In addition to these local reaction signs, there are other systemic manifestations (i.e. fever). Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. 20  Causes of Inflammation ‚ Direct physical damage ‚ Allergic reactions  Examples: cut, sprain ‚ Extremes of heat or cold ‚ Caustic chemicals  Examples: acid, ‚ Foreign bodies  Examples: drain cleaner splinter, glass ‚ Ischemia or infarction ‚ Infection Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. 21  Steps of Inflammation ‚ Injury to capillaries and tissue cells ‚ Release of bradykinin from injured cells ‚ Bradykinin stimulates pain receptors. ‚ Pain causes the release of histamine. ‚ Bradykinin & histamine cause capillary dilation. ‚ A break in the skin allows bacteria to enter the tissues ‚ Neutrophils phagocytize bacteria. ‚ Macrophages (mature monocytes) leave the bloodstream and phagocytose microbes. Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. 22  Types of Inflammation ‚ Inflammation is divided into two types: 1. Acute inflammation 2. Chronic inflammation ‚ Acute inflammation: is the early (almost immediate) reaction of local tissues and their blood vessels to injury; relatively short duration (few minutes to several days); characterized by exudation of fluid and plasma components and emigration of leukocytes (neutrophils) into extravascular tissues. Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. 23