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Living organisms verses inanimate objects. Characteristics of living organisms. Maintaining life processes. Normal vital functions Body systems operating to obtain oxygen, nutrients, Responding to environment and adapt to environmental stimuli Maintaining life in disease Treatments
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Living organisms verses inanimate objects Characteristics of living organisms
Maintaining life processes • Normal vital functions • Body systems operating to obtain oxygen, nutrients, • Responding to environment and adapt to environmental stimuli • Maintaining life in disease • Treatments • Biomedical Devices
First do no harm Supporting life processes
The Procaryotes Eubacteria Archaebacteria
The protists or protozoans Malaria is caused by four species of protozoan parasites Plasmodium falciparum Plasmodium vivax Plasmodium ovale Plasmodium malaria Trichomonads
Budding yeast • Beer! • Bread • Candidiasis – sometimes called thrush or yeast infections, can be very serious in immunodeficient patients
Plants – cells contain chloroplasts and carry out photosynthesis, i.e. convert sunlight CO2 and H20 to sugars
Animals Invertebrates – do not have a backbone Vertebrates do have a backbone
Life is all about energy - ATP • Cellular Respiration: is the process that releases energy by breaking down food molecules in the presence of oxygen. • Aerobic respiration occurs in the mitochondria. • Energy that is released by breaking food down is stored as ATP, • ATP is a short-term energy storage molecule • Cells use as ATP as their energy source.
The cell cycle. Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com)
Mitosis – • The four phases of cell division • Prophase • Metaphase • Anaphase • Telophase
Stem Cells * Embryonic stem cell come from early embryos – are totipotent * umbilical cord stem cells are multipotent. * Adult stem cells are multipotent
H&E section of a lung tumor with characteristic histopathology of a poorly differentiated carcinoma
Acorns, Mice, Ticks = Lyme Disease • Acorns are an important food source for many forest animals, including mice • Large crops of acorns in the fall lead to a booming mouse population the following summer. • Forest-living mice carry a spiral-shaped bacteria called Borrelia burgdorferi which causes Lyme disease. • As the population of mice increases the incidence of Lyme disease outbreaks increase. • Tick larvae feed on the mice and pick up bacteria. • More mice increase the number of infected ticks by providing tick larvae with more opportunities to pick up bacteria during feeding. • These larvae ultimately feed on humans or other animals and the rate of Lyme disease increases
Biofilmssheets or layers of bacteria on surfacesvery difficult to penetrate or treat
Pathogen Virulence Factors Host Immune Defenses Adhesins Innate response Toxins Inflammation Biofilm/capsule Adaptive response
Overview – Know your weapons • Physical barriers • Primary lymphoid organs – Thymus and bone marrow • Secondary lymphoid organs - l. n. spleen, and MALT
Types of Immunity • Innate or nonspecific immunity • Adaptive or acquired immunity • Humoral Immunity • Cell mediated immunity
Immunobiology of Respiratory Tract Infections Unique challenges of immunity within the respiratory tract: - Immense surface area exposed to environment - Generally sterile below the larynx
Bordetella pertussis infection – Whooping cough Initial colonization of the nasal cavity, spreads to lungs. Innate immune response Antibody production Clearing of the bacteria – resolution