Tuberculosis Flashcards
what is the relationship between HIV and TB?
suffers of TB and HIV will have much worse HIV symptoms as well as much worse TB symptoms. HIV patients also have an increased chance of contracting TB.
what is the genus if bacteria that causes TB?
mycobacteria
what is the mycobacterium which most commonly causes TB?
mycobacterium tuberculosis
people of what social history are most likely to be infected by TB?
people living in poverty, overcrowded conditions and with poor nutrition
is M. tuberculosis anaerobic or aerobic?
aerobic
given that M. tuberculosis is aerobic, where in the lungs is it most likely to be found?
the apices as V is high and Q is low
why is TB difficult for your immune system to fight off?
it has a uniquely thick wall which allows it to be resistant to neutrophil and macrophage destruction
is TB fast or slow growing?
slow
how does the fact that TB is slow growing affect the treatment is the condition?
is means that the treatment is a long process as antibiotics act in stage of cell division
what is the form of TB contracted from cows?
mycobacterium bovis
how can mycobacterium bovis be contracted?
through the consumption of infected cows’ milk (unpasteurised)
what is the source of M. tuberculosis?
from coming contact with someone with a case of open pulmonary TB (coughing and sneezing)
when droplets containing TB from a cough or sneeze are inhaled where must they land to cause an infection?
the alveoli
describe how TB causes tissue damage
- macrophages in the alveolus phagocytose the bacteria.
- they present antigens from the bacteria to Th cells in the lymph nodes
- Th1 cells specific to the antigen move back to the alveoli and ind to macrophages
- this induces the macrophages to become activated and are able to phagocytose more bacteria
5 however the activates macrophages release many compounds such as proteases which cause tissue damage in the alveoli
what type of giant cells are associated with TB?
Langhan’s giant cells
what forms when macrophages, epithelioid and langhan cells accumulate (like in TB)?
they form a granuloma
what is the cardinal sign of TB in histology?
central caseating necrosis
what happens in a resistant host when TB infects them?
little or no tissue destruction
organism is contained
little or no signs of disease
what happens when a susceptible host is infected by TB?
large amounts of tissue destruction
organism proliferates
progressive disease