1 Diseases, an overview
\definition{**Disease**}{an abnormal condition that causes impairment in/loss of function of an organism (a.k.a. decreased fitness) that is not due to immediate external injury.}
1.1 Causes of Disease
- Infectious agents
- Deficiency disorders
- Heritable factors
- Physiological disorders (immunodeficiency, autoimmune disorders, allergies, etc.)
1.2 Types of Diseases
1.2.1 Congenital Disease
Diseases present at birth due to DNA abnormalities / pregnancy pathological issues
1.2.2 Acquired Disease
Diseases that begin during the lifetime due to exposure to some environmental factors…
- Microrganism Invasion => "infectious disease"
- Autoimmune reaction => your body fighting your body
- Nutrient deficiency => not eating good
- Mechanical wear => wear and tear of physical body parts
- Ingestion of noxious chemicals => eating poison
An aside…
Infectious diseases actually smaller on the causes of death in the US
- Heart disease => wear + deficiency
- Cancer => heritable + DNA
- Unintentional injuries => not a disease
- Chronic respitory disease => wear
- Stroke => not a disease
- Alhetimer disease => wear
- Diabetes => autoimmune, nutrient, wear
- Influenca <= here, finally, an infections disease. *
1.3 Measuring diseases: pathogenicity + virulence
1.4 Disease-causing Agents
- Protozoan => single-celled eukaryotes
- Fungal => single/multi-celled eukarotyes
- Bacteria => single-celled prokaryotes
- Viral => acellular parasitic infectious agent
- Helminuthus => multicellular worms
- Prions => acellular misfolded proteins
- Viroids => infections nucleic acids w/o protein coat to make virus
1.4.1 Protozoan
- Protozoan factors => direction pathogenisis leading to tissue damage
- Host-mediated factors => immune evation + escape mechnisms + immunalsupression
Adaptable!!
1.4.2 Fungal
- Fungal factors => many shapes and very adaptable, colud produced specialized enzymes to take root in body
- Host-mediated factors => cause immunocomprimzation, acquired though inhalation, etc.
1.4.3 Bacteria
1.4.4 Viruses
See KBhBIO101Viruses