Ch 15 Flashcards
What are opportunistic pathogens?
microflora that are capable of causing disease if your health & immunity are weakened, and therefore become a pathogen
What are Prions?
small, modified, infectious host proteins (abnormally shaped versions of your own proteins)
**cause degenerative disease in the CNS
What is a zoonosis?
a disease passed from animals to humans
What does nosocomial mean?
acquired in the hospital
What is a fomite?
a nonliving object contaminated with infected body secretions
What are the 5 stages of infection?
Incubation Stage: active replication without symptoms
Prodromal Period: early s/s
Acute Stage: maximum manifestations, tissue damage & inflammation
Convalescent Stage: contain infection, eliminate pathogen, repair damage
Resolution Stage: total elimination, no residual manifestions
-itis
inflammation
-emia
in the blood
sepsis/septicemia
bacterial toxins in the blood
virulance factors
make an infection more likely to cause disease; these include exotoxins, endotoxins, adhesion factors, and evasive factors
How do antibiotics kill bacteria?
they target cell wall synthesis, protein synthesis, nucleic acid synthesis, and bacterial metabolism
How do antiviral agents kill viruses?
block RNA or DNA synthesis, block viral binding to cells, and block production of the capsids (protein coats) of new viruses
What does infection/colonization mean?
microorganisms are multiplying in or on the host
What is innate immunity?
the immune systems first line of defense; it is always present; attacks self from non-self; does NOT distinguish between different microbes
What cells are included in innate immunity?
- epithelial barriers
- phagocytic cells (neutrophils, macrophages, and dendritic cells)
- plasma proteins & NK cells
- cell messenger molecules
What is adaptive immunity?
immunity that is specific and involves memory of previously seen pathogens; adaptive immunity includes the antigen presenting cells (macrophages & dendrites) and the lymphocytes (t & b cells)
Review what a monocyte is…
monocytes circulate in the blood, & then migrate to the inflammatory site where they mature to become macrophages,
**as a phagocyte they are part of innate immunity, but then they can be antigen presenting cells which begin adaptive immunity
What is the role of neutrophils in immunity?
they play the most important role in innate immunity; they are usually NOT antigen presenting; they are the first responders in the inflammatory response; they have a short life & then die and become a part of purulent exudate
What is the role of dendritic cells in immunity?
they are found in their immature form under epithelial tissue and in organs; they capture and transport foreign agents to the closest lymph nodes; they mature in the lymph node & become antigen presenting cells; they also release mediators to help direct the adaptive immune system
What is the roll of B lymphocytes in immunity?
THEY PRODUCE ANTIBODIES
-mature into plasma cells in the bone marrow
What is the role of T lymphocytes in immunity?
- can be either t helper cells or t cytotoxic cells
- T Helper cells are needed for B cell to make antibodies
- T cytotoxic cells directly kill intracellular pathogens
- mature in the thymus
What is the role of NK cells in immunity?
- 1st line of defense against viruses
- kill tumor/mutated cells
- kill cells with intracellular bacteria
What is MALT?
mucosal associated lymphoid tissue (includes tonsils); this is where a large number of plasma cells live; often at or near a portal of entry
What are the components of the central lymphoid tissue?
bone marrow and thymus
