hemostasis/coag.

Question 1

Define hemostasis

Answer 1

cessation of bleeding from cut or severed vessel

Question 2

what are platelets produced from

Answer 2

megakaryocytes

Question 3

platelet survival time

Answer 3

8-10 days

Question 4

where doe plat. membrane come from

Answer 4

off megakaryocyte

Question 5

what is contained on plat. membranes

Answer 5

1. procoag. PS

2. surface receptors

Question 6

2 main platelet integrins and ligands

Answer 6

1. GP2b-3a - VWF and fibrinogen

2. GP1a-2a - collagen

Question 7

2 main platelet non-integrins and ligans

Answer 7

1. GP1b-9-5 - VWF

2. GP6 - collagen

Question 8

funct. of dense granules

Answer 8

storage of small weight molecules - ATP, Ca, ADP

Question 9

funct. of alpha granules

Answer 9

storage of proteins

- when activated, secreted

Question 10

define MI vs. ischemic stroke

Answer 10

1. MI in coronary art.

2. IS in carotid art.

Question 11

what causes adhesion

Answer 11

break in endothelium

Question 12

what happens during activation

Answer 12

secrete alpha and dense granules

Question 13

what happens after activation

Answer 13

cascade to create thromboxane A2 (TxA2) -aggregating agent

Question 14

what does aspirin do?

Answer 14

blocks COX-1 - an enzyme in cascade - can’t form TxA2

Question 15

what does TxA2 do

Answer 15

flip is procoag. PS to outside - promotes coag.

Question 16

what does PS on outside do

Answer 16

promotes platelets to aggregate together and form plug - primary hemostasis

Question 17

what tells the platelets to adhere

Answer 17

platelet receptors binding to collagen and VWF

Question 18

what is occuring in 2rd hemostasis

Answer 18

formation of fibrin strands - stabilize the 1st plug

Question 19

what is common name of factor I

Answer 19

fibrinogen

Question 20

common name for factor II

Answer 20

prothrombin

Question 21

what factors are missing in hemophilia

Answer 21

A. factor VIII

B factor IX

Question 22

4 factors that are vit. K dependant

Answer 22

II, VII, IX, X

Question 23

what are the 2 groups of factors involved in coag.

Answer 23

1. zymogens of serine proteases (enzymes_

2. cofactors - not enzymes

Question 24

what defines an activaed factor

Answer 24

add an “a” factor II to IIa

Question 25

2 main pathways of coag. cascade

Answer 25

1. extrinsic

2. intrinsic

Question 26

point where 2 pathways meet

Answer 26

Xa

Question 27

what begins extrinsic cascade

Answer 27

tissue factor from damages cell wall

Question 28

what does tissue factor activate in ext.

Answer 28

X to Xa

Question 29

what does tissue factor activate in int.

Answer 29

IX to IXa

Question 30

what starts intrinisic path

Answer 30

neg. charge surface contact phase

Question 31

intrinsic path to Xa

Answer 31

HK>XII>XI>IX + VII (requires Ca)

Question 32

what does Xa activate

Answer 32

prothrombinase > thrombin

Question 33

what is co-factor for Xa

Answer 33

Va

Question 34

2 main roles of fibrinogen

Answer 34

1. aggregate platelets

2. fibrin cascade

Question 35

factor involved in fibrinogen cascade

Answer 35

XIIIa

Question 36

what activates XIII

Answer 36

thrombin

Question 37

what 4 factors does thrombin feedback into

Answer 37

5,8,11,13

Question 38

final product of cascade

Answer 38

cross-linked fibrin polymer - stabilizes clot

Question 39

3 parts of cell-based model of coag.

Answer 39

1. initiation
2. amplification
3. propagation

Question 40

cascade of fibrinolysis

Answer 40

plasminogen>plasmin>lyses fibrin

Question 41

major inhibitor of thrombin

Answer 41

antithrombin (75%)

Question 42

what greatly potentiated antithrombin

Answer 42

heparin - use this an anticoagulant