Exam 1: Coagulation disorders

Question 1

thrombosis

Answer 1

the formation of an inappropriate intravascular clot (fibrin, platelets,) on the wall or freely within the lumen

Question 2

thrombus

Answer 2

actual intravascular clot

Question 3

thrombosis occurs when

Answer 3

appropriate/normal fibrinolytic mechanisms fail to resolve clot properly during normal hemostatic events

Question 4

ideal normal blood clot shouold be large enough to stop bleeding but not large enought to

Answer 4

occlude blood vessel

Question 5

clot should be present only long enough to

Answer 5

allow healing of underlying vascular tissue

Question 6

a thrombus can fragment or completely dislodge from primary site to form a

Answer 6

embolus or more appropreately termed thromboembolus

Question 7

what is an embolism

Answer 7

the act of placing abnormal particulate matter into the circulation

Question 8

particles within circulation are called

Answer 8

emboli

Question 9

underlying causes of thrombotic disease are often ____

Answer 9

multifactorial

Question 10

the three factors that greatly influence thrombus formation are termed Virchow’s triad and include

Answer 10

damage to endothelium
alteration in blood flow
hypercoagulability

Question 11

damage to endothelium

Answer 11

provides focus for clot formation

Question 12

alteration in blood flow

Answer 12

increased turbulence or increased statis

Question 13

hypercoagulability of blood components

Answer 13

increased platelet activity
increased coagulation factor activity or increased coagulation factor activation
decreased natural inhibitors of coagulation

Question 14

decreased antithrombin is well recognized in veterinary medicine

Answer 14

severe hepatic insufficiency (chronic or acute)
protein losing nephropathy and protein losing enteropathy
increased consumption (DIC)

Question 15

decreased protein C

Answer 15

potential role for prognostic indicator; decreased in some equine colic and septicemia patients

Question 16

what are the possible sequela if a thrombus or thrombi are formed

Answer 16

resolution secondary to fibrinolysis
organization plus/minus recanalization
enlargement/propagation leading to vascular obstruction
thromboembolism

Question 17

resolution secondary to fibrinolysis (no long term effects)

Answer 17

complete dissolution following healing of underlying vessel wall

Question 18

organization plus/minus recanalization

Answer 18

in-growth of fibroblasts, endothelial cells and smooth muscle cells
blood flow will renew as capillaries anastomose
will gradually decrease in size as connective tissue contracts

Question 19

enlargement/propagation leading to vascular obstruction if involves artery

Answer 19

will cause ischemia unless collateral circulation exists

Question 20

enlargement/propagation leading to vascular obstruction in vein

Answer 20

local edema, pain, swelling due to impaired drainage

Question 21

what is the most common reason for an infarct

Answer 21

lodging of an embolus or thromboemolus

Question 22

infarct

Answer 22

area of ischemic necrosis created by infarction usually well-demarcated

Question 23

infarct usually due to

Answer 23

thrombotic or emobolic event

arterial obstruction but may occur with venous obstruction

Question 24

development of an infarct is usually influenced by

Answer 24

type of vascular supply to tissue, rate of occlusion formation and sensitivity of tissue to oxygen deprivation

Question 25

some of the tissues/organs are highly susceptible to infarction due to

Answer 25

poor collateral circulation

Question 26

do thrombi adhere to vessel walls?

Answer 26

yes, thrombi firmly adhere to vessel walls

Question 27

thrombi are composed primarily of platelets will be _____ in color

Answer 27

pale

Question 28

thrombi containing many RBC will often be _____

Answer 28

red

Question 29

____ thrombi will often be pale due to rate of flow, it prevents RBC from being incorporated into the thrombus

Answer 29

arterial

Question 30

thrombi in larger arteries may also have a _____ appearance, as multilayers of platelets, interspersed with fibrin, RBC, WBC, that get incorporated over time

Answer 30

laminated

Question 31

_____ thrombi will often be dark red in appearance due to the incorporation of erythrocytes into the thrombus due to the lower blood flow in these vessels

Answer 31

venous

Question 32

venous thrombi tend to be _____

Answer 32

gelatinous, soft, and glistening

Question 33

venous thrombi often occlude and _____ to the lumen of blood vessles

Answer 33

mold

Question 34

venous thrombi tend to extend _______ of th ethrombi as it continues to enlarge proximally when blood constituents come into contact with the thrombi

Answer 34

upstream

Question 35

post mortem clots will resemble ____ thrombi

Answer 35

venous

Question 36

post mortem clots firmly adhered to vessel walls?

Answer 36

no

Question 37

in the heart or large vessels, post mortem clots will often have a _____ appearance, as the RBC will sediment to the dependent side of the clot

Answer 37

chicken fat

Question 38

post-mortem clots will also be devoid of

Answer 38

lesions on the vessel wall

Question 39

thrombi appearance on H&E

Answer 39

generally intraluminal eosinophilic, smooth to laminar material partially or completely occludes the vessel; adhearing to tunica interna; RBC, WBC, fibroblasts and endothelial cells will be noted

Question 40

what tissues are prone to ischemic necrosis

Answer 40

kidney, heart, and brain

Question 41

overtine, the affected area undergoes necrosis, swelling, and inflammation, the infarction will progressively become ____

Answer 41

paler; and eventually begin to shrink, as inflammation subsides and firbosis eventually replaces normal tissue

Question 42

acute infarcts on H&E

Answer 42

have hemorrhage, congestion, neutrophilic and/or fibrinous inflammation; loss of normal cell viability

Question 43

clinical signs depend on

Answer 43

the organ involved and amount of collateral circulation

Question 44

pulmonary thromboembolus signs

Answer 44

acute dyspnea

Question 45

gi signs

Answer 45

abdominal pain

Question 46

CNS signs

Answer 46

neurologic signs

Question 47

distal aorta signs

Answer 47

paresis, cool limbs, no femoral pulses

Question 48

common diseases associated with thrombosis include (but not limited to)

Answer 48

corticosteroid therapy/cushings neoplasia nephrotic syndrome heartworm disease

Question 49

what is disseminated intravascular coagulation (DIC)

Answer 49

severe multifactorial disorder which occurs secondary to many primary disorders/proccesses

Question 50

these disorders/processes include

Answer 50

severe tissue trauma, disseminated bacteial infections, viral infections, neoplastic conditions, immune-mediated diseases

Question 51

DIC can have clinical bleeding if

Answer 51

clotting factors, inhibitors/promoters of clotting, and/or platelets have been depleted due to excessive clotting

Question 52

a primary disease process provides a potent trigger to activate widespread _____

Answer 52

clot formation in capillaries and small vessels

Question 53

this activation overwhelms the normal control mechanisms in place to

Answer 53

prevent/limit thrombus formation

Question 54

DIC results in widespread _____ formation in microvasculature

Answer 54

fibrin

Question 55

consequences are often

Answer 55

tisue ischemia and consumption of platelets, coagulation factors, natural inhibitors, and fibrinolytic factors

Question 56

ischemia often leads to

Answer 56

hypoxia or anoxia and localized or systemic metabolic acidosis

Question 57

if DIC is severe enough, it can result in

Answer 57

multiorgan failure and death

Question 58

DIC may often be recognized with

Answer 58

cpetichiation, ecchymosis, or bleeding

Question 59

underlying mechanisms associated with DIC

Answer 59

stagnant blood flow endothelial damage release of large quantitis of tissue factors release of particulate matter (phospholipids, microparticles) release of proteolytic enzymes into blood decreased clearance of activated coagulation factors consumption of inhibitors of coagulation

Question 60

gross DIC appearance

Answer 60

widespread, multifocal areas of petechia and ecchymosis in tissue hemorrhage or hematomas may be present a primary dz process may be observed

Question 61

DIC on H&E

Answer 61

microthrombi are hallmark larger thrombi may be present primary dz process

Question 62

clinical signs of DIC

Answer 62

petechia/ecchymosis spontaneous bleeding/hematoma following venipuncture organ dysfunction due to occlusion, anoxia will not be specific

Question 63

common disorders associated with DIC

Answer 63

``` massive trauma spesis, septicemia, endotoxemia neoplasia (vascular tumors) necrotizing pancreatitis IMHA vasculitis snake bite: VIC ```