Transcript 3/19
Vaccines: HPV and HIV Immune System Taking in food and oxygen exposes us to pathogens esophagus stomach Pathogen: an organism that causes disease CB 18.2 E. coli Phage virus Ebola Fungus from soil various pathogens Viruses only harm cells by invading them and using the cell to reproduce Living organisms must fit all of the following criteria: 1. They must have organization. 2. They must have metabolism. 3. They must respond to the environment. 4. They must be able to reproduce themselves. A typical bacteria CB 6.6 CB 52.12 The rapid growth of bacteria stationary exponential lag Human Population Growth CB 52.22 36.4 9 2.3 How much of our society is based on continuing population increases? 36.4 9 2.3 A typical bacteria CB 6.6 What do bacteria do? from a human perspective Good • Decay dead material • Help digest food • Protect body from “bad bacteria” • Nitrogen fixation • Produce oxygen Bad • Cause disease – – – – Food poisoning STD’s Cavities Infections of skin or body • Spoil food/infect crops CB 54.17 The nitrogen cycle Nitrogen as part of amino acids and nucleotides N N N What do bacteria do? from a human perspective Good • Decay dead material • Help digest food • Protect body from “bad bacteria” • Nitrogen fixation • Produce oxygen Bad • Cause disease – – – – Food poisoning STD’s Cavities Infections of skin or body • Spoil food/infect crops ~40% of planted food does not make it to table Evolution in Action: Resistance of bacteria to antibiotics What do bacteria do? from a human perspective Good • Decay dead material • Help digest food • Protect body from “bad bacteria” • Nitrogen fixation • Produce oxygen Bad • Cause disease – – – – Food poisoning STD’s Cavities Infections of skin or body • Spoil food/infect crops ~40% of planted food does not make it to table Taking in food and oxygen exposes us to pathogens esophagus stomach The Immune System • Non-specific: – barriers CB 43.2 • Specific: –B-cells -> antibodies –T-cells Non-Specific Immune System Barriers: Skin- Dry Inhospitable Competition Secretions (lysozyme) Hairs and Mucus (protect openings) Traps particles, swallowed Stomach acid kills pathogens CB 43.2 CB 43.2 Skin protects us from most pathogens Non-Specific Immune System Barriers: Skin- Dry Inhospitable Competition Secretions (lysozyme) Hairs and Mucus (protect openings) Traps particles, swallowed Stomach acid kills pathogens CB 43.2 esophagus stomach Non-Specific Immune System Barriers: Skin- Dry Inhospitable Competition Secretions (lysozyme) Hairs and Mucus (protect openings) Traps particles, swallowed Stomach acid kills pathogens CB 43.2 How do vaccines to work? By pre-activating the body’s immune system.