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Unformatted text preview: PORTALS OF ENTRY 1. M UCOUS MEMBRANES---many bacteria and viruses gain access to the body by penetrating the mucous membranes of the respiratory, digestive, or genitourinary tracts, or by penetrating the conjunctiva (mucous membrane that lines the eyelids). The respiratory tract is the most frequent site of entry. Microbes are inhaled in drops of moisture or dust particles. The common cold, pneumonia, tuberculosis, influenza, measles, and smallpox are commonly contracted this way. Microorganisms gain access to the gastrointestinal tract through food, water, and contaminated fingers and objects put into the mouth. Many of these microbes are destroyed by the hydrochloric acid and enzymes of the stomach, or by bile and enzymes in the small intestine. Some pathogens can survive and cause infection, including those causing polio, hepatitis A, typhoid fever,...
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This note was uploaded on 01/23/2012 for the course MCB MCB2010 taught by Professor Smith during the Fall '09 term at Broward College.
- Fall '09