2 - Hemodynamic Disorders, Thrombosis, and Shock Flashcards
Blood from hemorrhage may accumulate in body cavities. What is the specialized term for accumulation of blood in the pleural cavities?
Hemothorax
Describe the gross appearance (colour) of edema fluid.
Clear to slightly yellow
Is edema fluid a transudate or an exudate?
Transudate (low protein content)
Describe the gross appearance of lungs affected by chronic congestion due to heart failure.
The lungs are moderately FIRM and YELLOW-BROWN to TAN. [The tan colour is because of alveolar macrophages containing hemosiderin from alveolar hemorrhage. Inflammatory mediators produced by these macrophages also induce fibroplasia, thus there is extensive formation of interstitial collagen in the long term. This collagen is the reason the lungs fail to collapse after loss of negative pressure in the pleural cavity when the diaphragm is incised at necropsy.]
What is the pathogenesis whereby malnutrition may lead to generalized edema?
Malnutrition -> inadequate uptake of protein substrates from gut -> insufficient protein substrates (amino acids) available for liver to be able to synthesize albumin -> reduced hepatic synthesis of albumin -> reduced levels of plasma proteins -> reduced intravascular osmotic pressure -> generalized edema
Arrange the following hemorrhages by size, from largest to smallest:
(a) Ecchymosis
(b) Petechiae
(c) Purpura
(d) Suffusive
(d) Suffusive > (a) Ecchymosis > (c) Purpura > (b) Petechiae
List the four basic, underlying mechanisms that result in edema.
- Increased hydrostatic pressure; 2. Decreased intravascular osmotic pressure; 3. Decreased lymphatic drainage; 4. Increased vascular permeability
What is the basic underlying reason for the reduced intravascular osmotic pressure that may result in edema?
Decreased plasma proteins (more specifically, albumin) in circulation
What is the pathogenesis whereby severe intestinal parasitism may lead to generalized edema?
Intestinal parasitism -> ingestion of blood, including plasma proteins, by parasites -> reduced levels of plasma proteins (beyond liver’s ability to regenerate them quickly enough) -> reduced intravascular osmotic pressure -> generalized edema
Of the following 4 factors that can influence development of edema, which may be DECREASED when edema develops?
(a) Hydrostatic pressure
(b) Intravascular osmotic pressure
(c) Lymphatic drainage
(d) Vascular permeability
(b) Intravascular osmotic pressure and (c) lymphatic drainage
Blood from hemorrhage may accumulate in body cavities. What is the specialized term for accumulation of blood in a joint?
Hemarthrosis
What is the pathogenesis by which internal breakdown of red blood cells (e.g., caused by hemolysis or hemoabdomen) leads to icterus?
Blood breakdown -> massive release of bilirubin -> overwhelms liver’s ability to process it -> accumulates in tissues, most noticeably in lightly pigmented tissues such as sclera, fat and skin -> icterus (= jaundice)
What is a typical underlying cause for GENERALIZED edema resulting from increased intravascular hydrostatic pressure?
Heart failure, which causes passive accumulation of blood (congestion)
Blood from hemorrhage may accumulate in body cavities. What is the specialized term for accumulation of blood in the cavity around the heart?
Hemopericardium
What is the primary driving force creating intravascular osmotic pressure?
The presence of plasma proteins
What is the underlying reason for reduced lymphatic drainage of a site, and what are two possible causes of this?
Underlying reason: blockage or compression of lymphatic vessels. Possible causes include: (a) Compression by tumors or nearby inflammatory swelling; (b) Blockage by lymphatic vessel inflammation & fibrosis, by tumors or by clots.
Give two possible (common) reasons why a liver might have acute passive congestion at necropsy.
(1) Sudden heart failure resulting from arrhythmias; (2) Euthanasia. [Acute passive congestion occurs in the vascular system and dependent organs (heart, lungs, portal system) when there is a sudden interruption of the return of blood to the heart, as occurs in heart failure resulting from arrhythmias and after euthanasia.]
Which term(s) mean(s) increased volume of blood at a particular anatomic location?
(a) Ascites
(b) Congestion
(c) Hyperemia
(d) Icterus
(e) Infarction
(b) Congestion and (c) hyperemia
Where does all lymphatic fluid ultimately end up, and how does it get there?
In the systemic (blood) circulation; it is returned here from the lymphatic system by a major lymphatic duct entering a large vein cranial to the heart (typically into the cranial vena cava)
What is the term used for hemorrhages that are greater than 1 to 2 cm in diameter?
Ecchymoses (or ecchymotic hemorrhages)
What are the three fluid compartments in the body? That is, where can INTERNAL fluids (i.e., not in the bladder, stomach etc.) be located?
Intravascular; Interstitial (Intercellular); Intracellular
How are ascites and hydrothorax different?
Ascites means fluid (edema) accumulation in the peritoneal cavity; hydrothorax means fluid accumulation in the pleural cavities