Cell degeneration and death 3

Question 1

Congestion

Answer 1

accumulation of blood in a vascular bed due to reduced or obstructed outflow

Question 2

Hypostatic congestion

Answer 2

gravitational pooling of blood in a dead animal

ex if animal was lying on back at death blood can pool in caudal-dorsal region of lung

Question 3

Chronic passive congestion of the liver (seen with right heart failure)

Answer 3

Elevated central venous pressure
Venous back-up
Congestion in Zone 3 
progresses to zone 3 ischemic necrosis
results in "nutmeg liver"

Question 4

What else can be seen in chronic passive congestion (for example in dogs)

Answer 4

fibrin - as it polymerizes on the surface of the liver

Question 5

Chronically congested lungs (due to left heart failure) appear?

Answer 5

rusty colour due to hemosiderin in alveolar macrophages (this is due to macrophages digesting RBC)
-this blood has leaked from pulmonary capillaries

Question 6

Significance of congestion

Answer 6

signals circulatory problem
predisposes to thrombosis
leads to edema
dependent on degree and duration of vascular obstruction, oxygen depletion may lead to hypoxic necrosis/infarction of cells/tissue

Question 7

Conjunctivitis

Answer 7

inflammation of the conjuntiva

-hyperemia of dilated capillaries on the scleral surface

Question 8

Hyperemia

Answer 8

inflammation promotes hyperemia
microvascular damage may cause thrombosis and congestion in inflammation as well
Fibrinous exudate (leaking from damaged vessels) will often cover the inflamed eroded mucosal surfaces

Question 9

Hemorrhage

Answer 9

exravasation of blood= leakage of erthyrocytes and plasma into the interstitial space

Question 10

Petechiae/ecchymoses

Answer 10

pinpoint hemorrhages due to : bacterial septicemia, systemic viral infection, thromboyctopenia, vasculitis, DIC

Question 11

Hemopericardium often results in?

Answer 11

cardiac temponade

Question 12

Significance of hemorrhage depends on?

Answer 12

site or location

rate and volume of blood loss (shock, blood loss anemia)

Question 13

Diagnostic significane of hemorrhage

Answer 13

trauma
vessel defect/rupture (eg aneurysm) 
vasculopathy and/or clotting defect
-clotting factor deficiency/thrombocytopenia
-sepsis 
-endotoxemia

Question 14

Fate of hemorrhage

Answer 14

Whether diffuse or focal/localized, hemorrhages are reabsorbed by the body
RBC are broken down and catabolized
A hematoma is progressively converted to CT through the process of wound repair

Question 15

Where does edema tend to accumulate

Answer 15

in loose tissues

-

Question 16

Hydrothorax

Answer 16

clear edema fluid free in the pleural space

Question 17

Outcomes of edema

Answer 17

vary with location and duration
if cause is reversible, edema and fluid in body cavities is reversible in early stages 
Impact on tissue
-space occupying compression
-impaired function (pulmonary edema)

Question 18

Chronic edema leads to

Answer 18

fibroplasia/fibrosis

Question 19

Thrombosis

Answer 19

inappropriate coagulation of blood in the lumen of a vessel

Question 20

Embolus

Answer 20

a mass that travels in the bloodstream and eventually lodges in a vessel

Question 21

Common causes of severe thrombosis

Answer 21

Severe trauma
sepsis/septicemia
Vascular injury 
Shock
Protein-losing nephropathy/enteropathy
Cancer
Cushing's disease in dogs

Question 22

Fates of thrombus

Answer 22

resolution
embolization to lungs
Recanalized and orgainzed into side of the wall

Question 23

Consequence of large vessel thrombi

Answer 23

occlusion of vessel
-ischemic necrosis/infarction
thromboembolism
-distant infarction; sepsis if thrombus is infected
vasculitis, degeneration of vessel wall at site of thrombu

Question 24

Significance depends on:

Answer 24

rapidity of development
completeness of occlusion
availability of collateral circulation
metabolic requirements of affected tissue field