560A: Pathophysiology Flashcards
Pathophysiology
Etiology:
cause of disease
Diagnosis:
determination of the nature and cause of a patient’s illness
Cardinal signs of inflammation:
a. dilation (expansion) of blood vessels
b. increased vascular permeability
c. attraction of leukocytes (white blood cells) to site of injury
d. heat, redness, tenderness, swelling, pain
e. systemic response (fever, leukocytosis)
Causes of inflammation:
a. chemical agents (mediators) of inflammation that are formed & released when tissue is damaged; some are from cells; others from proteins in blood plasma
b. when antibodies and antigens (toxin or foreign bodies) interact; causes inflammatory response followed by tissue necrosis
Acute inflammation:
a. 1st line of defense in response to injury
b. nonspecific
c. may occur in response to any injury in short of one that is lethal
d. short duration
e. exudation of fluid & emigration of leukocytes
f. occurs before immune response
g. goal to remove injurious agents
Chronic inflammation:
a. non-degradable pathogens
b. lasts for several months to years
c. failure to rid whatever was causing an acute inflammation
Lymphocytes:
a. respond to foreign antigens, macrophages and related cells that process antigen and “present” it to lymphocytes;
b. important cells of immune system that communicate with one another;
c. secrete lymphokines that are chemical messengers
Complement system - 2 pathways of activation
- classical pathway - triggered by antigen-antibody interactions
- alternative pathway - activated by bacterial cell wall material or products generated during inflammation
Antibodies:
globulins produced by plasma cells and are usually called immunoglobulins
5 Classes of Antibodies
- IgM
- IgG
- IgA
- IgD
- IgE
Components of Healing Process: Type 1 - Immediate Hypersensitivity
a. allergy
b. IgE antibodies
c. antigen-antibody interaction
d. antihistamines
e. desensitization w/IgA & IgG (i.e. - food allergy)
f. anaphylaxis (i.e. bee sting)
g. mediator from mast cells & basophils
Components of Healing Process: Type 2 - Cytotoxic Hypersensitivity
a. antibody attaches to antigen
b. complement activated followed by cell tissue damage
Components of Healing Process: Type 3 - Immune Complex Disease
antigen-antibody complexes form; activate complement and cause inflammatory reaction
i.e. rheumatoid arthritis
Components of Healing Process: Type 4 - Delayed (Cell-Mediated) Hypersensitivity
T-lymphocytes secrete cytokines that attract lymphocytes, macrophages, and other inflammatory cells
i.e. tuberculosis, contact dermatitis
Control and Complications of Healing: Suppression of the Immune Response
a. unwanted effects of immune response
(autoimmune disease, rejected transplanted organs, Rh hemolytic disease in newborn infants)
b. methods for suppressing - radiation, cytotoxic drugs, adrenal corticosteroids, antibodies
c. tissue grafts and immunity (foreign antigens; lymphocytes reject foreign antigens; immune suppression to prevent rejection)
Control and Complications of Healing: Autoimmune Diseases
a. pathogenesis - antibodies formed, cross-reaction, T-lymphocytes fail to control immune response
b. treatment - corticosteroids, cytotoxic drugs
c. connective tissue diseases (autoimmune diseases)
i. e lupus erythematosus, scleroderma