MICR 2123 Lecture Notes - Lecture 18: Macrophage, Helicobacter Pylori, Gas Gangrene
Document Summary
There exist a lot of microorganisms in and on our human body: most are harmless if they stay where they belong, some are even beneficial. The human body is also under constant attack from microbial invaders: we have barriers. For those that are successful in invading, we have adaptive and nonadaptive immune defenses. Skin is typically dry, also epidermal secretions are salty. Gram + bacteria are more resistant to salt and dryness: staphylococcus epidermis, propionibacterium acne. Nose and mouth: colonization starts within hours of birth, mostly with harmless bacteria, all colonizers need to be able to adhere to surfaces to avoid flushing to acidic stomach, both gram and + are present. Mostly aerobes but anaerobes also appear in gingival crevices or tonsillar pits: ex. Respiratory tract: microorganisms are constantly inhaled into the lungs, the ciliated mucosal epithelium of the trachea, bronchi, and bronchioles makes up the mucociliary elevator. Sweeps foreign particles up and out of the lung.
