Circulatory Disturbance Flashcards
The relationship between the various forces at work in the microcirculatory
bed is described by what is known as the
Starling Equilibrium
Mechanisms Of Edema
The mechanisms of edema include the following mechanisms:
1) Decreased plasma colloid osmotic pressure
2) Increased blood hydrostatic pressure
3) Increased vascular permeability
4) Lymphatic obstruction
Recall that plasma electrophoresis
separates the constituents of plasma to
albumin, alpha, beta, and gamma
globulins
is the most important plasma protein, and is principally
produced in the liver
Albumin
the obstruction and lymphatic channel damage is caused by parasites such as
filarial worms as observed in __________ in humans.
elephantiasis
Morphology Of Edema
➢ The changes associated with edema are dependent on:
• the severity of edema
• the rapidity of onset,
• the extent,
• the anatomic location, and
• the underlying cause of edema.
in the subcutaneous tissue takes the form of fluid
collections that may be tinged red with blood or other colors
depending on the underlying cause.
Edema
Edema fluid collects in the lowermost portions of the body such as the
ventral abdomen and the limbs as influenced by gravity in a pattern
referred as
dependent edema
When such edema is severe and generalized, it is possible to push a finger
against such edematous tissue and produce a dent. Such a change is
described as .
pitting edema
is recognized by excess clear fluid and is most easily visualized
beneath the skin or between the layers of mucous membranes or in
lobules of the lung, where there is space for accumulation to occur.
Edema
– generalized edema or extreme edema in the entire body, as
occurs in some aborted fetuses.
Anasarca
– common lesion affecting lungs and is often the
immediate cause of death in many different disease conditions (i.e.,
resultant of left congestive heart failure or LCHF).
Pulmonary edema
Edema is such a characteristic lesion in some specific diseases that it is
incorporated into the name of the disease:
▪ Gut edema caused by Escherichia coli in pigs
▪ Malignant edema caused by Clostridium septicumin in
several species
– fixative of choice to retain edema lesion
Bouin’s fluid or solution
Types of Edema
- Localized edema
- Generalized edema (as in anasarca)
In active process, edema is an:
Exudate
Exudate – an inflammatory effusion or edema characterized
by:
•
- high protein content
• increased specific gravity
• increased number of inflammatory cells
In passive process, edema is a:
Transudate
Transudate – a non-inflammatory effusion or edema
characterized by:
• Low protein content
• Low specific gravity
• Low or absence on inflammatory cells
The term _______ refers to a local increase in the volume of blood in
tissues due to dilation of the small blood vessels
hyperemia
refers to the
damming of blood in an area due to diminished venous outflow, and is considered
a form of passive hyperemia. Yet, the two are oftentimes used as synonyms
congestion
occurs following an increase in demand for more blood as in exercise,
Physiological
hyperemia
on the other hand occurs as a manifestation of some
alterations in blood flow characteristics. It is not however, the cause of the
alteration, rather, the result of some underlying pathological process. These
include those observed during inflammation, in cardiac failure, and obstructive
venous diseases.
Pathological hyperemia
Three factors are considered in the classification of pathological hyperemia, and
includes the following:
- Duration of hyperemia (acute or chronic)
- Extent of hyperemia (general or local)
- The underlying mechanism (active or passive)
Thrombosis is the formation of ante mortem clot within the blood vessels, and the
clot formed is called
thrombus
Hemostasis, or the arrest of hemorrhage by clot formation involves five
essential steps:
- vascular contraction,
- stasis of blood,
- endothelial adhesion,
- blood coagulation, and
- platelet aggregation.
