Ch11: Bleeding and clotting disorders

Question 1

Hemostasis

Answer 1

process that prevents bleeding following injury involves a complex interaction of blood vessels, platelets, and chemical coagulation factors in plasma

Question 2

blood vessels during hemostasis

Answer 2

undergo spastic contraction in response to injury aids by decreasing BF to area spasm of smooth muscle can occlude vascular lumen- stop bleeding. shunting of blood to other non-injured vessels provides circulation limiting injury to tissue

Question 3

platelets during hemostasis

Answer 3

obstruct BF, promote vasoconstriction, release chemicals that further hemostatic process and facilitate clot retraction in healing phase. platelets stick to surface=adhesion adhesion + aggregation of platelets to each other as they form a platelet plug (plug may be sufficient alone for hemostasis in small vessels)

Question 4

blood coagulation/clotting

Answer 4

process of plasma from a liquid to a solid fibrinogen -> fibrin (stringy, strong, insoluble protein thrombus

Question 5

coagulation/clotting cascade

Answer 5

formation of fibrin happens through a series of enzymatic steps the product of each step catalyzes and augments the next step. reaction can slow/stop by inhibitors 2 enzymes: thrombin and factor XIII

Question 6

thrombus

Answer 6

blood clot- contains fibrin with entrapped RBCs and platelets

Question 7

thrombosis

Answer 7

clotting in a blood vessel

Question 8

organized thrombus

Answer 8

thrombus converted into scar tissue

Question 9

virchow’s triad

Answer 9

1: endothelial cell injury 2: stasis or turbulence of BF 3: hyper-coagulability

Question 10

pulmonary embolism

Answer 10

thrombus forms in vein, dislodges and gets stuck in pulmonary arteries

Question 11

thrombocytopenia

Answer 11

decreased number of circulating platelets includes bone marrow failure and peripheral destruction of platelets spontaneous bleeding may be anticipated when the platelet count drops below 10,000 mcL or when platelets are defective

Question 12

petechiae

Answer 12

small hemorrhages

Question 13

epistaxis

Answer 13

nose bleeds

Question 14

hematuria

Answer 14

blood in urine

Question 15

hematochezia

Answer 15

fecal blood

Question 16

menorrhagia

Answer 16

excessive menstrual bleeding

Question 17

hematoma

Answer 17

localized collection of blood

Question 18

purpura

Answer 18

blood in skin

Question 19

disseminated intravascular coagulation (DIC)

Answer 19

serious condition in critically ill patients develop fibrin thrombi in small vessels throughout the body, and at the same time bleed extensively throughout vessels. simultaneous clotting and bleeding makes it difficult to treat

Question 20

hemorrhagic diathesis

Answer 20

pt with a tendency to bleed

Question 21

coagulopathy

Answer 21

abnormality in the coagulation mechanism leading to either excessive bleeding or excessive clotting

Question 22

tests

Answer 22

1. Platelet count: 150,000-400,000
2. Bleeding time: no longer used
3. Platelet function analyzer (PFA 100)
4. Activated partial thromboplastin time (aPTT)
5. Prothrombin time (PT)
6. D-dimer

Question 23

PFA

Answer 23

measures platelet dependent coagulation under flow conditions

Question 24

PTT

Answer 24

blood sample drawn, add calcium- activates coagulation system- 30s normal, measures heparin effectiveness

Question 25

PT

Answer 25

used to assess disorders disorders of extrinsic pathway of coagulation. expressed in terms of INR- compares pt's PT to normal population- used to follow pt's on warfarin therapy

Question 26

vascular disorders

Answer 26

most common vascular causes of hemorrhage are trauma and diseases that erode blood vessels

Question 27

idiopathic thrombocytopenia purpura (ITP)

Answer 27

autoimmune disease in which the body makes antibodies to platelets