Lecture 15: Granuloma Flashcards
what is pleural fluid?
5-10ml of clear fluid that lubricates the apposing surfaces of the visceral and the parietal pleura during respiratory movements
how is this fluid formed?
from the hydrostatic and osmotic pressures
what happens if the pleural fluid accumulates?
reduces lung expansion and leads to respiratory compromise and hypoxia
explain transudate effusions (6)
low protein
low specific gravity
low cellular content
caused by an imbalance of hydrostatic and oncotic pressure
associated with kidney, heart or liver failure or hypoalbuminemia
explain exudate effusions (2)
high protein content
high specific gravity
what are exudate effusions caused by?
increased permeability of capillaries - which can be caused by the serous membranes being damaged due to disease such as metatstatic malignancy, infections, and connective tissue disease
why is thoracocentesis conducted?
trying to find the cause of pleural effusion
to help patients breath easier
what is found in a CT for granuloma
hepatomegaly - enlarged liver
what does carcinoma in the lung look like? (6)
large central area of caseous necrosis
structureless material with destruction of the lung parenchyma
caseous zone surrounded by a cellular zone that contains epithelioid cells and giant cells
large multinucleated giant cells
large number of lymphocytes
explain foreign body granulomas (4)
caused by inert foreign bodies
form around talc, sutures, or other fibres that are too large to be phagocytosed
absence of inflammatory or immune response
foreign material can be seen in the middle of the granuloma if viewed with polarised light
explain immune granulomas (3)
caused by agents that induce a persistent T-cell mediated response
immune response produces granulomas when the agent is difficult to eradicate
macrophages activate T cells to produce cytokines which activate other T cells = cycle
what does acid fast mean?
the resistance of acid based stains, means organisms can resist decolourisation
give an example of an acid fast bacteria
mycobacterium tuberculosis
what is the difference between granulation tissue and granulomatous inflammation?
granulation tissue contains new small blood vessels, fibroblasts and mononuclear cells in an oedematous extracellular matrix - part of the repair response
a granuloma is circumscribed collection of epithelioid cells surrounded by lymphocytes = chronic inflammation
do granulomas look different in different organs?
no
