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

What is death?

The Procaryotes

Archaebacteria Eubacteria

The protists or protozoansMalaria 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

The Life Cycle of Influenza Virus

• 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.

Life is all about energy - ATP  

Reproduction in procaryotes

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

Development

Stem Cells

* Embryonic stem cell come from early embryos – are totipotent

* umbilical cord stem cells are multipotent.

* Adult stem cells are multipotent

Mouse embryonic stem cells

H&E section of a lung tumor with characteristic

histopathology of a poorly differentiated carcinoma

Cancer

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 surfaces

very difficult to penetrate or treat

Adhesins

Toxins

Innate response

Adaptive response

Pathogen

Virulence Factors

Host

Immune Defenses

Inflammation

Biofilm/capsule

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

Nonspecific immune response

Specific or Acquired Immunity Antigens and Antibodies

Immunobiology of Respiratory Tract InfectionsUnique 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