edema Flashcards
define edema
abnormal accumulation of water in tissues or body cavities
list the gross characteristics of edema
- Swollen, usually soft and doughy, distended tissue that tends to gravitate ventrally
- Edematous tissue pits on pressure and the indentations remain after the pressure is removed
- Edematous tissue is cool to the touch rather than warm (unless inflammation is also present)
- The edematous tissue is not reddened (not hyperemic) or painful (again, unless inflammation is also present)
- Distended lymphatics are often visible in edematous lesions
- At postmortem examination, edema is recognized by the presence of clear yellow-tinged fluid that distends loose connective tissues or accumulates in body cavities such as the peritoneal, pleural, or pericardial spaces. The fluid may flow upon cutting through the tissue or, if the vessels were damaged sufficiently that clotting proteins accompanied the fluid, it may form a yellowish jello-like clot.
what is the cause of edema disease?
septicemia of certain strains of E. coli. These bacteria produce a toxin that acts on endothelial cells, allowing fluid to leak out.
what does it mean if the histology had spaces that were clear?
edema is protein-poor
what does it mean if the histology had spaces that were pink?
edema fluid has abundant protein
true or false: edema is often dorsal
false: ventral
how does reticulopericarditis occur?
occurs when the cow eats a piece of wire that ends up migrating through the reticulum to the pericardium.
how do you know there is edema in a histology if the fluid is clear?
spaces around vessels are widened because they were distended by edema
what is generalized edema?
accumulation of fluid everywhere
what does anasarca typically refer to?
generalized massive edema affecting all parts of the body of a fetus
what does hydro mean?
added to the anatomic site to denote edema in a particular area
a cat was infected with feline infectious peritonitis virus and had hydrothorax. what is the pathology?
prolonged viremia with production of a high antibody titer - the antigen-antibody complexes deposit in the vessel walls, damaging them and allowing fluid to leak out
a horse was infected with african horse sickness virus and caused hydropericardium, what is the pathology?
This virus infects endothelial cells in the heart (and also lung) and causes them to be leaky
what else does edema fluid consist of besides water?
protein, leukocytes and erythrocytes
define transudate
accumulation of fluid due to a hydrostatic imbalance between the intravascular and extravascular compartments despite normal vascular permeability
what are some characteristics of transudate edema?
- vascular permeability is normal, there will be little protein or blood cells accompanying the fluid (clear and colorless)
- specific gravity < 1.018
- protein content < 2.5 g/dl
- few cells; most of those present are mesothelial cells rather than leukocytes
- low fibrinogen
true or false: transudate has a low specific gravity
true
define exudate
accumulation of fluid due to increased vascular permeability
what does exudate edema fluid look like and why?
opaque/amber because of high specific gravity
what are characteristics of exudate
- high (> 1.018) specific gravity
- high (> 2.5 g/dl) protein content,
including fibrinogen - numerous cells, especially
leukocytes