4.8 Homeostasis Flashcards Preview

Pathology > 4.8 Homeostasis > Flashcards

Flashcards in 4.8 Homeostasis Deck (103)
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61

hemorrhage

petechiae, purpura, ecchymosis, hemothorax, hematoma

62

petechiae

1-3mm

63

purpura

>3mm <1-2cm

64

ecchymosis

>1-2cm

65

rapid loss of up to ___. of blood volume or slow losses of more can be tolerated by young healthy individuals

20%

66

epidural bleeds are

areterial

67

subdural bleeds are

venous

68

Hemostasis

maintainance of flow and generation of hemostatic plug at sites of hemorrhge

69

clot

coagulated blood

70

thrombus

coagulated blood inside of a vascular space - almost always pathological

71

normal endothelium secretes

antiplatelet PGI2 that keeps flow gowing

72

anti-thrombin III

inactivates thrombin and other activated factors

73

heparin-like molecules also promote

flow

74

thrombomodulin

converts thrombin into an activator of protein C

75

Protein C cleaves

factors 5a and 8a (Va and VIIIa)

76

Prtein C needs

protein S form endothelial cell

77

t-PA

tissue plasminogen activator makes plasmin to promote flow

78

NO

nitric oxide keeps vessesl open constitutively mad by endothelial cells

79

laminar flow favours flow by

keeping cells away from cell walls

80

Most potent stimulus for coagulation

collagen bc you don't normally see collagen in your vessels

81

if there is a chunck of endothelial cell loss then

collagen is exposed to plasma promoting coagulation

82

platelets cannot bind collagen without

vonWillebrand factor - that factor has receptors for platelets and ECM__allows for aggregation activation and secretion of platelets

83

tissue factor

extrinsic pathway activated by LPS and cytokines induce endothelial cells to produce TF (DIC)

84

On injury endothelial cells change phenotype

form proflow to pro thrombotic -- stop secreting prostacylin and mitric oxide and secrete procoagulation things instead

85

Injured tissues releases

tissue factor to start the coagulation path

86

platelet functions

adhesion,
secretion

87

adhesion

vWF binds to collagen and platelets

88

secretion

alpha granules, dense bodies

89

alpha granules

fibrinogen, PDGF, TGF-b, vWF, platelet factors IV

90

Dense bodies

ADP, Ca2+, histamine, serotonin, epinephrine, TXA2, and phospholipid complex