|Edema is accumulation
excessive water in body cavities or interstitial tissues.
of Edema = abnormal accumulation of water in tissues or
of edema include:
- Swollen, usually soft and doughy, distended
tissue that tends to gravitate
- Edematous tissue
pits on pressure and the indentations remain after the pressure is
- Edematous tissue
is cool to the touch rather than warm (unless inflammation is also
- 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
distends loose connective tissues or accumulates in body cavities
such as the peritoneal,
pericardial spaces. The fluid may flow upon cutting through the
tissue or, if the vessels
sufficiently that clotting proteins accompanied the fluid, it may
form a yellowish jello-like clot.
Here is a pig
that was suffering from "edema disease," which is due
to a septicemia of certain strains of E. coli. These bacteria
produce a toxin that acts on endothelial cells, allowing fluid to
Eyelid is a favored
spot for this edema to be manifest. This pig can't even open its
eye because the lid is so swollen with
BY THE WAY, the word for eyelid edema is CHEMOSIS. Add that to your ever-expanding lexicon!
features of edema include:
- separation of
tissue elements by spaces that are either clear (if the edema is
protein-poor) or pink (if the edema fluid has abundant protein).
edema fluid fills areas that are not supposed to have fluid. Here
is a section of lung - protein-rich fluid has leaked out of the vessels
and is filling alveoli and bronchioles (*).
This is bad nooz.
Can't do no air exchange if there is fluid in these spaces....
Here is another
photomicrograph of edema. In this case, the submucosa of the gut,
which is represented by the bottom two-thirds of the photo, is
markedly distended by fluid.
demonstrates a lymphatic which is also way big. With all this
expansion, the nutrients and
oxygen just have a heck of a time diffusing through to where
they need to go.
This horse had a Salmonella infection, and this bug likes to damage the blood vessels of the gut - EDEMA (and much much more unfortunately).