BIO 126 Lecture Notes - Lecture 9: Blood Plasma, Immunoglobulin Heavy Chain, Lipopolysaccharide
21 Mar 2016
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Document Summary
Bacteria: major entry points through direct bodily contact, open wounds, inhalation, and ingestion. Viruses: nucleic acids enclosed in a protein coat, must infect host cell to replicate, may kill host cell rapidly or lie dormant for a period, may cause cancer. Eukaryotic parasites: protists, fungi, worms, damage host by using host nutrients or secreting toxic chemicals. Defenses against pathogens: nonspecific defenses - broadly effective, no prior exposure (innate) Phagocytic cells, antimicrobial proteins, inflammation and fever: specific defense - results from prior exposure, protects against only a particular pathogen (adaptive) Body surface: few microorganisms can penetrate intact body surface, skin glands secrete antimicrobial molecules (mild acids and enzymes, mucus is sticky to trap invaders and antimicrobial, stomach acids destroy invaders. External barriers 1st line of defense: skin. Lactic acid (acid mantle) is a component of perspiration: subepithelial areolar tissue. Tissue gel: viscous barrier of hyaluronic acid.
