Immuno, Lecture 1 Flashcards
(23 cards)
Pathogenic organisms
Virus: small particle, not alive
- shows property of being alive when contacted with host -intracellular affecting agent
ex: HIV, polio, Hep B
Bacteria: waterborne illnesses kill millions
ex: mycobacteria (TB), bacteroides (GI),
Protozoa: divide/replicate much more rapidly than human cells
- antibiotics disrupt their replication
ex: malaria, trypanosomes
Worms/helminthes: tape worms
Fever Clinical Correlation
optical density vs. temperature (Fahrenheit)
the most growth of bacteria occurs at our normal body temperature but once the temperature increases, growth is inhibited thus the need/necessity for fever!!
Yeast Infection Correlation
Lactobacillus acidophilus is a major component of vaginal microflora
Metabolism of glycogen by L. acidophilus results in pH of 5.0 that prevents vaginal colonization by yeasts which often causes vaginitis (inflammation of vagina resulting in discharge and itching)
Microflora
community of organisms that live in a particular habitat (GI, skin, oral…)
numerous amounts found in intestine important in molecular signaling for immune system
Germ-free animals
Germ free animals are obtained from cesarean section (do not go through microflora in vagina)
If kept in sterile conditions, they will not develop commensal microflora
Germ Theory
a particular germ can cause a particular disease needs Koch’s postulates
Koch’s postulates
I. Infected tissue must show the presence of a particular microorganism that is not found in healthy animals
II. The microorganism must be isolated and grown in a pure culture;
III. When injected into a healthy animal, the microorganism must cause the disease associated with it
IV. This “second generation” microorganism should then be isolated
Gram Positive Bacterial Infection
Use of crystal violet turns the sample purple due to binding to peptidoglycan
Gram Negative Bacterial Infection
Normally a pink color does not have very much peptidoglycan instead has lipopolysaccharides (LPS)
Intracellular Pathogens
Cytoplasmic: Bacteria, viruses, protozoa,
Vesicular: Bacteria, mycobacteria
Immune functions:
NK cells
T cells
Macrophages
CTLs
Intracellular Microbes: invade and replicate intracellularly in animal cells utilize host-cell energy sources
Extracellular Pathogens
Immune function against:
Intraepithelial PMNs cells
Antibodies
Extracellular Pathogens: able to survive in animals by growing extracellularly and being submersed in nutrients
Mycobacterium Tuberculosis
causes tuberculosis
Macrophage activation resulting in granulomatous inflammation and tissue destruction
Endotoxins
components of bacterial cell wall only used when bacteria is destroyed because otherwise it is needed for membrane integrity
all gram negative bacteria have endotoxins
Exotoxins
actively secreted by the bacteria
Extracellular bacteria
replicate outside of the host cell:
- circulation
- connective tissue
- airways
- GI tract
2 pathogenic mechanisms:
- bacteria causes inflammation which results in tissue destruction (fever)
- bacteria produce toxins with pathological effects (endotoxins and exotoxins)
Autoimmune response
immune function is disrupted and recognizes self as pathogen
Antigens recognized to imitate a response onto itself
Antigen (Ag)
non-infectious foreign substance and can elicit an immune response
Collateral Damage
cell/tissue damage that occurs due to inflammation or other processes to destroy pathogen normally self inflicted
Primary Fixed Elements
Bone marrow- provide mature B cells
Thymus- provide mature T cells
Secondary Fixed Elements
- Spleen and lymph nodes
- Mucosal immune tissues
Mobile Elements
Immune cells
Soluble (Humoral) components
- antibodies
- complement
- acute phase proteins (cause fever)
Mast cell
derived from basophils found only in tissues (not in the circulation)
Monocytes
precursor to macrophages monocytes are found in circulation macrophages are found in the tissue
