Path 404 Sp 2008 Hemostasis

Front 1

Megakaryocytes

Back 1

Large bone marrow cells that produce platelets.

Front 2

Aspirin

Back 2

Inhibits activation of platelets (platelet inhibition). Used to prevent excessive blood clotting for at risk patients.

Front 3

Vitamin K

Back 3

Fat soluble vitamin found in many leafy, green vegetables. Required for synthesis of several components in coagulation cascade.

Front 4

Fibrinogen

Back 4

Inactive form of clotting enzyme; thrombin cleaves to fibrin, which polymerizes to form clot.

Front 5

Plasminogen Activators

Back 5

Molecules that convert inactive plasminogen to plasmin (active). Activators are stimulated by clot formation.

Front 6

(bone) Marrow Failure

Back 6

Causes thrombocytopenia, a decrease in platelet production.

Front 7

Hemophilia

Back 7

Coagulation protein deficiency inherited from X chromosome; absence of one of two clotting factors, resulting in defective fibrin clot formation.

Front 8

Thrombocytopenia

Back 8

Low platelet count often resulting in bleeding. Can be caused by decreased production or increased consumption.

Front 9

von Willebrand Disease

Back 9

Partial absecne of vWF, resulting in mild to moderate bleeding. Transmitted by dominant inheritance; can be carried by either parent.

Front 10

Arterial Embolus

Back 10

May originate in heart or large arteries; clot may travel to brain, which can cause stroke.

Front 11

Venous Embolus

Back 11

Usually originate in legs, traveling through heart and into lungs (pulmonary embolism).

Front 12

von Willebrand Factor

Back 12

Glue like protein made by endothelial cells and secreted into blood and subendothelium. Very sticky; can grab platelets even in rapidly flowing blood.

Front 13

Tissue Factor

Back 13

Trigger substance for coagulation cascade when in contact with blood; substance found in most cells. Cascade started by TF is called "extrinsic pathway".

Front 14

Thrombin

Back 14

End product of cascade; cleaves fibrinogen to fibrin. Requires vitamin K to produce special binding regions on proenzyme/enzyme.

Front 15

Fibrin

Back 15

Protein that polymerizes to form glue-like coating around platelet plug. Cross-linking also occurs to strengthen plug.

Front 16

Immune Thrombocytopenic Purpura (ITP)

Back 16

Platelet destruction due to either autoimmune reaction or drug induction. Can be chronic or acute.

Front 17

Warfarin

Back 17

**DISCOVERED AT UW-MADISON!!**
Anticoagulant that blocks the effects of vitamin K, essentially creating a vit K deficiency that reduces clotting

Front 18

Stroke

Back 18

Cerebral Infarction: Loss of blood flow to part of the brain due to embolism (clot occluding blood vessel).

Front 19

Pulmonary Emblous

Back 19

clot that has broken loose (usually from legs) and travels through heart and becomes lodged in lungs.

Front 20

What are the three major functional requirements of the hemostatic system?

Back 20

*Prevent Bleeding
*Maintain Blood Fluidity
*Allow Wound Healing

Front 21

What are the 5 basic steps of the clotting process?

Back 21

1. Injury damages blood vessel.
2. Platelets stick, aggregate to provide area for fibrin binding.
3. Coagulation factors activated to form fibrin on plug surface.
4. Vasoconstriction limits flow to area.
5. Fibrinolytic system dissolves clot; replaced by conn. tissue

Front 22

T/F. The coagulation cascade is a series of linked enzyme reactions.

Back 22

TRUE.

Front 23

What is the active enzyme that dissolves a clot after bleeding stops?

Back 23

plasmin

Front 24

Regulation- What three proteins are responsible for turning off the coagulation cascade?

Back 24

*Antithrombin-inhibits thrombin
*Protein C-degrades active coag factors
*Protein S- cofactor for protein C

Front 25

Which type of ITP is generally temporary, and which is a more permanent condition?

Back 25

childhood (acute) usually temp,
adult(chronic) usually requires immunosuppression/splenectomy.

Front 26

What are the three principle of Virchow's Triad?

Back 26

1. Blood Vessel Injury
2. Stasis of Blood
3. Hypercoagulability

Front 27

Explain the relationship between risk of bleeding and/or excessive clotting with platelet count.

Back 27

Lower platelet count increases chance of bleeding.
High platelet count increases risk for excessive clotting (thrombus/embolus).

Front 28

Disseminated Intravascular Coagulation

Back 28

Exposure of blood to procoagulant/profibrinoltyic enzymes causing uncontrolled clotting. Usually associated with serious/life threatening conditions.