Transes

• The body protects itself from pathogens through various mechanisms, including the first line of defense which consists of physical barriers such as the skin and mucous membranes.
• The second line of defense is nonspecific and attempts to destroy all types of foreign substances that are harmful.
• The third line of defense is very specific and involves special proteins called antibodies and memory T-cells who have the ability to create memory specific for a particular pathogen.
• General immunity serves to protect the body against many harmful substances.
• Specific host defense mechanisms include five major immunoglobulin classes (MADGE).
• Attenuated vaccines should not be given to immunosuppressed individuals, examples include BCG (for tuberculosis), OPV (polio), MMR (measles mumps rubella), and ROTAVIRUS (viral diarrhea).
• Inactivated vaccines are produced faster and more easily but are less effective, they produce a shorter period of immunity, examples include DPT (DIPHTHERIA, PERTUSSIS/WHOPPING COUGH AND TETANUS), Hepatitis B vaccine, and Rabies Vaccine.
• One of the most nonspecific host defenses is the innate, or inborn, resistance observed among some species of animals and some persons who have a natural resistance to certain diseases.
• The first line of defense consists of physical barriers such as the skin and mucous membranes which protect the body from invading bacteria and parasites, though some can penetrate intact skin.
• A person can get infected if there is a cut or an abrasion, injecting drugs through needles, and insect bites.
• Goblet cells produce mucus that can entrap invaders.
• The acidity (pH - 5.0) and temperature (37 °C) of the skin inhibit growth of pathogens.
• The oily sebum that is produced by sebaceous glands in the skin contains fatty acids, which are toxic to some pathogens.
• Perspiration or sweating flushes organisms that are trapped on the pores.
• The enzyme, lysozyme, which is contained in perspiration, degrades peptidoglycan in bacterial cell walls, especially Gram-positive bacteria.
• The sloughing off of dead skin cells removes potential pathogens from skin.
• Cilia protects the respiratory system.
• The two most important groups of phagocytes include: Macrophages and Neutrophils.
• Saliva and tears contain lysozyme, digestive enzymes, and acidity of stomach (pH 1.0), alkalinity of intestines, peristalsis, frequent urination, and acidic vaginal pH (pH 4.0) which stimulates Lactobacillus to grow.
• The objective of immunization is to stimulate the recipient’s immune system to produce protective antibodies and/or memory cells.
• In viruses, immunization stimulates the production of antibodies directed against the surface antigens, preventing the pathogens from adhering to the host cells.
• The 3 major events of inflammation are: Vasodilation, increased capillary permeability, accumulation of leukocytes in site of injury.
• Chemotaxis: attracts WBC especially those that are phagocytes.
• Humoral Immunity involves the production of antibodies in response to antigens and attacks the antigens that stimulated them, providing immunity to a particular pathogen.
• Monocytes are larger and develop into macrophages that are responsible for inflammatory reactions.
• The 4 cardinal signs and symptoms of inflammation are: Redness, heat, swelling, pain, loss of function.
• Inflammation: a series of events in which the body normally responds to local injury, inflammation, bacteria and the like.
• WBC - Granulocytes have no granules, while Lymphocytes have blue nuclei.
• Cellular Immunity involves various cell types most especially T-cells.
• The Reticuloendothelial system includes cells in the liver (Kupffer cells), spleen, lymph nodes, and bone marrow as well as the lungs (alveolar or dust cells), blood vessels, intestines, and brain (microglia).
• Phagocytosis is carried out by phagocytes, the process of surrounding and engulfing foreign material.
• The two types of macrophages are: Fixed Macrophages which stay in tissues and Wandering Macrophages which migrate to other sites.
• There are 4 branches of Humoral Immunity: IgM, IgA, IgD, IgG, and IgE.
• The purpose of inflammation is to localize infection and promote healing.
• Lactoferrin prevents Iron from binding to microbes.
• Nonspecific cellular and chemical responses are the second line of defense.
• The complex sequence of events includes fever, interferons, complement system, inflammation, chemotaxis, phagocytosis. These are examples of second line defense.
• The complement system is a group of approximately 30 proteins that are found in normal plasma, named as such because it is complementary to the action of the immune system.
• Endogenous pyrogens include Interleukin-1 produced by white blood cells (WBC) and endotoxin produced from Gram-negative bacteria.
• Lactoperoxidase is antimicrobial and toxic to microbes.