Ch. 22 In class notes Flashcards
(82 cards)
1
Q
physiologic prevention of blood loss
A
hemostasis
2
Q
hemostasis is controlled by
A
activators and inhibitors
3
Q
key mediators of vascular constriction
A
thromboxane A2
serotonin
endothelin-1
4
Q
when there is an injury and collagen is exposed, what binds and activates platelets?
A
vWF
5
Q
once vWF binds and platelets change shapes, they release what
A
granules- ADP, TXA2, Ca+2
6
Q
binds fibronogen and cross-links platelets
A
GPIIb/IIIa (glycoprotein)
7
Q
the most powerful vasoconstrictor
A
endothelin-1
8
Q
if TA2 or endothelin-1 impairment
A
liver failure
9
Q
receptors on platelet that vwf binds to after vwf leaks
A
glycoprotein
10
Q
binding of vwf doesnt happen so no clotting
A
vwf disorder
11
Q
receptors exposed when platelet change shape
A
alpha and gamma granules
12
Q
secrete vwf
fibrinogen
pdgf
factor 5
factor 8
A
alpha-granules
13
Q
secrete ADP
ATP
Ca+2
serotonin
histamine
A
gamma-granules (dense)
14
Q
amplifies aggregation
A
granule release
15
Q
targeted by antiplatelet drugs
A
aspirin
clopidogrel
16
Q
slow contact activated pathway
A
intrinsic
17
Q
fast tissue factor pathway
A
extrinsic
18
Q
coagulation intrinsic and extrinsic cascades converge on
A
factor x-thrombin-fibrin
19
Q
stabilizes the platelet plus
A
fibrin
20
Q
in heparin induced thrombocytopenia causes lowering of cells…?
A
factor 4
21
Q
platelets contract via actin-myosin to shrink clot
A
clot retraction
22
Q
plasminogen to plasmin dissolves fibrin
A
fibrinolysis
23
Q
main activator of clot retraction
A
tissue plasminogen activator
24
Q
fibrin breakdown
A
d-dimers
25
extrinsic pathway regulated by
factor 7
26
factor 7 triggers
factor 10- happens in 15 seconds in extrinsic
27
intrinsic pathway takes
1-6 minutes
28
clot retraction takes
20-60 mins
29
why measure d-dimer
endothelin injury translate into fresh fibrin. shows that may be DVT, pulm embolism, DIC. if normal rules out new clots
30
inhibits thrombin, Xa (enhanced by heparin)
antithrombin 3
31
inactivate factors 5 and 8
proetin C and S
32
inhibits tissue factor pathway
TFPI
33
needed for y-carboxylation of 2, 7, 9, 10, and proteins c and s. sources are green vegetables, gut flora. deficiency is increase PT/INR first then aPTT. target of warfarin therapy
vitamin K
34
ptt tests for
intrinsic pathway. expect hemophilia or vwf disease
35
test for fibrinogen and d-dimer if low fibrinogen and high d-dimer
DIC*
36
stasis, endothelial injury, hyperstability. increased risk of dvt, pe, stroke, pregnancy loss
Virchow's triad
37
pt with antithrombin 3 deficiency why is there a clotting problem?
cannot maintain hemostasis. favors ?coagulants, not anticoagulants
38
infection, inflammation, iron deficiency
reactive thrombocytosis
39
clonal megakaryocyte disorder. release large poorly shaped platelets. JAK2 mutations
essential thrombocythemia
40
have warm and burning skin extremities. fingers are red bc of high # platelets clogged in extremities
essential thrombocythemia
41
high platelet counts cause
thrombosis and hemorrhage
42
hypercoagulability that results from high amount of clotting factors and low amount of natural anticoagulation's like protein c/s and AT3. presents with VTE at young age or unusual sites
thrombophilia's
43
procoagulants (factor v leidem, prothrombin g20210a) natural antigoagulants (protein c,s, at 3 deficiencies)
inherited thrombophilias
44
APC resistance cannot inactivate factor 5
factor 5 leiden
45
prothrombin thrombin
prothrombin g20210a
46
promotes coagulation by activating tumor cells to trigger cytokines to be released. starts coagulation cascade
cancer
47
increases CF production
estrogen, immobility, surgery, trauma, stasis
48
autoimmune thrombophilia
antiphospholipid syndrome
49
autoimmune antibodies against phospholipid binding proteins. recurrent clots, fetal loss, thrombocytopenia
antiphospholipid syndrome
50
labs for APS
lupus anticoagulant
anticardiolipin
anti-beta2-glycoprotein 1 (bc interferes with normal anticoagulant function of the beta2 receptor on the plt)
51
treatment of antiphospholipid syndrome (gets rid of autoantibodies and other antibodies susceptible to infection)
anticoagulation (heparin/warfarin), immunosuppression
52
35 yo f with lupus has 3 miscarriages and now presents with left leg swelling. doppler confirms DVT. labs show lupus anticoagulant, aaPTT, + anticardiolipin IgG
antiphospholipid syndrome
53
thrombocytopenis platelet count
under 150,000
54
bleeding risk when plt count less than
50,000
55
spontaneous bleeding when
less than 10,000
56
marrow failure, immune, dic, splenomegaly are causes of
thrombocytopenia
57
petechiae, purpura, mucosal bleeding
thrombocytopenia
58
IgG against PF4-heparin leads to platelet activation leads to thrombosis
heparin-induced thrombocytopenia
59
if find thrombocytopenia and increased megakaryocytes you know marrow tries to compensate
ITP
60
autoantibodies to platelet surface glycoproteins leads to clearance. no anemia or splenomegaly
idiopathic thrombocytopenia purpura
61
thrombosis
HIT
62
bleeding
ITP
63
first line of treatment for ITP
? and immunoglobulins to get rid of autoantibodies
64
chronic ITP may need to do
splenectomy
65
antibody activated plt after give heparin
HIT
66
pts have an antibody that stops heparin from working. binds to plts where heparin was supposed to bind so heparin does not bind to plt and is not effective. will release procoagulants that cause plt count to go down but is hyperfunctional bc cannot be stopped so after 5-10 days of heparin must monitor coagubility state to assess if heparin is inducing this or not
HIT
67
thrombotic thrombocytopenia purpura is caused by
ADAMTS13 deficiency
68
clinical pentad:
-thrombocytopenia
-microangiopathic hemolytic anemia
-meurologic sx
-renal dysfunction
-fever
(must act immediately)
TTP
69
cleaves vWF causing aggregation. deficiency causes microthrombi
ADAMTS13
70
uremia, nsaids, myeloproliferative disorders can impair the function of
plt leading to bleeding disorders
71
a 66 yo m undergoes a TURP and experiences prolonged bleeding despite normal CBC. he was taking aspirin for CAD. labs are normal plt count, prolonged bleeding time, normal PT/aPTT
post-op bleeding on aspirin
72
x-linked recessive, affects males
hemophilia
73
factor 8 deficiency. decreased quantity or function. impairs thrombin production cause delayed onset bleeding
hemophilia a
74
factor 9 deficiency xmas disease
hemophilia b
75
bleeding in joints as a baby
severe hemophilia
76
management of hemophilia
avoid nsaids
recombinant factor 8 replacement
prophylactic infusions for severe disease
gene therapy under investigation
77
most common inherited bleeding disorder. little amount of factors or defective version of it
vwd
78
helps plt stick to vessel wall. keeps factor 8 stable
vwf
79
frequent nose bleeds, heavy menstruation
vwd
80
releases vwf from storage site. given if type 1
desmopressin
81
factor 8 and vwf transfusion given in
type 2/3
82
pt clotting and bleeding at the same time
DIC
