circulatory disorders part 2 Flashcards Preview

Path 1 sum 2017 > circulatory disorders part 2 > Flashcards

Flashcards in circulatory disorders part 2 Deck (45):
1

hemorrhage

defined as the escape of blood from the blood vessels (extravasion)

can be internal or external (within tissues or body cavities)

2

causes of hemorrhage

trauma

sepsis, viremia, bacteremia, toxic conditions

coagulation abnormalities (defect or deficiencies)

abdominal neoplasia (hemoperitoneum can be caused)

3

hemorrhage vs hyperemia

hemorrhage: blood outside vessel wall

hyperemia/congestion/ blood within vessels

4

hemorrhage clinical significance

determined by location and severity

profuse blood loss is most common cause of hypovolemic shock

hemorrhage in the brain or heart can be fatal

5

Q image thumb

hemopericardium 

leads to fatal cardiac tamponade

6

hemorrhage by rhexis

due to substantial rent or tear in vascular wall (or heart)

A image thumb
7

dissecting aneurysm

in additon to horses they are also reported in young male racing greyhounds

can lead to arterial rupture and fatal hemorrhage

A image thumb
8

hemorrhage by diapedesis

due to small defect in vessel wall or rbc passing through a vessel wall in cases of inflammation or congestion (like in the lungs of animals with left sided CHF)

A image thumb
9

hemorrhage diathesis

increased tendency to hemorrhage from usually insignificant injuries (seen in a wide variety of clotting disorders)

10

hemothorax

hemoperitoneum

hemarthrosis

hemoptysis

 

 

hemothorax- blood in thoracic cavity

hemoperitoneum- blood in peritoneal cavity

hemarthrosis- blood within a joint space

hemoptysis: coughing up of blood or blood stained sputum form the lungs or airways

11

epistaxis

bleeding from nose

12

classification according to size

Q image thumb

petechia

up to 1-2 mm in size. especially found on skin, mucosal and serosal surfaces

13

classification according to size

Q image thumb

ecchymosis

larger than petechia 1-2cm 

bruise or small hematoma

14

Q image thumb

agonal hemorrhages

petechiae and ecchymoses associated with terminal hypoxia

15

Q image thumb

suffusive hemorrhage

larger than ecchymosis and contiguous

serosal surface of stomach, dog

16

Q image thumb

paint brush hemorrhage

looks like if red paint was hastily applied with a paint brush. most common on mucosal and serosal surfaces

17

hemorrhage resolution small vs large amounts

small amounts can be absorbed

larger amounts require phagocytosis and degradation by macrophages

 

organizing hematoma: central mass of fibrin and red blood cells surrounded by supportive vascular connective tissue --> macrophages will eventually phagocytize this lesion

18

cause of coloration

Q image thumb

A image thumb
19

hemostasis

 

arrest bleeding by physiological or surgical means

 

A image thumb
20

the pathological form of hemostasis is ________ in which a ________ forms within a vessel which is not injured or only mildly injured

the pathological form of hemostasis is _thrombosis_______ in which a __a clot (thrombus)______ forms within a vessel which is not injured or only mildly injured

21

general components necessary for normal hemostasis or thrombosis to occur

1. vascular wall

2. platelets

3. coagulation cascade

blood clotting is physiological necessity whereas thrombosis is a pathological manifestation of blood coagulation

22

steps of normal hemostasis

initial injury

brief period of arteriolar vasoconstriction occurs

augmented by local secretion of factors such as endothelin

endothelial exposes highly thrombogenic subendothelial ECM allowing platelets to heal (glycoprotein 1b receptors to von willebrand factor and be activated)

platelet aggregation to form hemostatic plug; process is primary hemostasis

tissue factor III thromboplastin. acts to activate coagulation pathway with factor VII

thrombin cleaves fibrinogen to make insoluble fibrin creating a fibrin meshwork deposition

thrombin induces further platelet recruitment and granule release

secondary hemostasis lasts longer than initial platelet plug

23

“Endothelial cells are key players in the regulation of _________, as the balance between the anti- and prothrombotic activities of endothelium determines whether __________, _________, or __________ occurs” 

“Endothelialcellsare key players in the regulation of homeostasis, as the balance between the anti- and prothrombotic activities of endothelium determines whether thrombus formation, propagation, or dissolution occurs” 

24

coagulation cascade

amplifying series of enzymatic conversions (culminating in thrombin formation)

 

at conclusion of proteolytic cascade thrombin converts soluble plasma protein fibrinogen into fibrin

 

coagulation factors are plasma proteins produced mainly by the liver

 

25

thrombosis

formation or presence of a solid mass within the CV system

26

pathogenesis of thrombosis

endothelial injury

alterations in blood flow

hypercoagulability (increase in coagulation factors and decrease in coagulation inhibitors)

27

Q image thumb

A image thumb
28

Q image thumb

pulmonary thromosis (dog)

 

seen in dogs with severe renal glomerular disease --> protein losing nephropathy --> significant loss of antithrombin III, a major inhibitor of thrombin

29

Q image thumb

verminous thrombosis

 

thrombus formation in the cranial mesenteric artery of horses with strongylus vulgaris infection

30

Q image thumb

strongylosis

colon, horse

31

Q image thumb

saddle thrombosis

cat with HCM

thrombis located in trifucation of abdominal aorta

32

outcome of thrombi

lysis, propagation, embolization, organization/recanilization

A image thumb
33

embolism vs embolus

embolism: when a piece of the thrombus breaks off from original mass and sails downstream lodging at a distant site. process is called emoblism

 

embolus: the mass that breaks off is called embolus

34

Q image thumb

fat embolism 

 

could be complication of long bone fractures

picture: bone marrow emboli in pulmonary artery. secondary to CPR resusciation efforts

35

Q image thumb

infectious causes of thrombis/thromboembolism

 

bacterial valvular endocarditis in cattle and give rise to septic emboli that lodge in pulmonary arteries

36

Q image thumb

thrombotic meningoencephalitis

 

etiology: histophilus somni infection- results in vasculitis and thrombosis

37

disseminated intravascular coagulation (DIC)

signs of tissue hypoxia, infarction or/and hemorrhage are seen 

38

Q image thumb

fibrin thrombi within glomerular capillaries (disseminated intravascular coagulation)

 

PTAH stain

39

infarction

localized area of ischemic necrosis in a tissue or organ caused by occlusion of either the arterial supply or the venous drainage

 

 

40

Q image thumb

venous infarct

intensely hemorrhagic as blood backs up into the affected tissue behind the obstruction

41

Q image thumb

arterial infarcts are often initially hemorrhagic but become pale as the area of coagulation necrosis becomes evident

42

Q image thumb

microscopically an infarct is a focal area of coagulation necrosis

43

shock

cardiovascular collapse

 

shock is the final commonpathway for a number of potentially lethal clinical events (severe hemorrhage, trauma/burns, myocardial infarction, massive pulmonary embolism and microbial species)

 

shock gives rise to systemic hypoperfusion (caused by reduced cardiac output or reduced effective circulating blood volume)

can lead to multiorgan system failure

44

types of shock

cardiogenic (heart doesn't maintain normal cardiac output)

hypovolemic (fluid loss dur to hemorrhage/vomiting/diarrhea)

blood maldistribution (anaphylatic Type 1 hypersensitivity, neurogenic, septic)

45

pathogenesis of septic shock

most cases of septic shock are caused by endotoxin producing gram negative bacilli (endotoxic shock)