Biochem Of Coagulation

Front 1

What is the basic synthesis of a platelet?

Back 1

Hematopoietic stem cells--> Megakaryocytes-->Platelets.
•
1MK=4,000P

Front 2

What are the basic functions of platelets?

Back 2

• Platelets form mechanical plugs as site of vessel injury
•Secrete regulators of the clotting process and vascular repair.

Front 3

What activates platelets? (6 things)

Back 3

1)ADP
2)Epinephrine
3)Collagen
4)Thrombin
5)Immune complexes generated during infection
6)High physical stress

Front 4

What does platelet adhesion refer to?

Back 4

• Adhesion refers primarily to the platelet-subendothelial interaction that occurs when platelets initially adhere to the sites of blood vessel injury.

Front 5

Describe Von Willibrands Disease?

Back 5

Associated with platelets
and
1)Most common coagulation disease
2)Increased or easy bruising
3)Acute hemorrhage from the nose
4)Heavy menstrual bleeding
5)Postoperative bleeding
6)Family history
7)Bleeding from wounds
8)Gingival bleeding
9)Postpartum bleeding

Front 6

What is bernard-Soulier syndrome?

Back 6

A glycoprotein disorder where
(Gplb-IX) affects the platelet membrane glycoprotein (GP) GPIB/IX--> resulting in a lack of aggregation and adherence

Front 7

Tell me about Glanzmann’s thrombasthenia

Back 7

(GPIIB)(GPIIB-IIIa) is bleeding disorder characterized by a decrease or absence of the functional platelet membrane glycoprotein(GP) complex

Front 8

Define the mechanism of activation of protein S and C?
(This is long)

Back 8

1)Supress the activity of the coagulation cascasde
2)After activation C forms a complex with S
3)S anchors the complex to the clot.
4)Proteins S and C are regulatory proteins
5)Only C is regulated by proteolytic cleavage.
6)When it becomes activated it is a serine protease.
7)Protein S is the cofactor for protein C
8)Protein S anchors protein C (APC) to the clot through gammacarboxyglutamate binding to platelet phospholipids.
9)APC=activated protein C.
10)APC destroys factor VIIIa and factor Va by proteolytic cleavage
11)Stimulates endothelial cells to increase secretion of prostaglandin PGI2

Front 9

Outline control points of coagulation cascade.

Back 9

--Inhibitors of platelet activation
--Aspirin=cyclooxygenase inhibitor
--Thromboxane synthetase inhibitors
--GPIIB-IIa antagonist
--Block platelet affregation in acute coronary thrombosis
--ADP inhibitors
--ADP receptor inhibitors

Front 10

Explain how endothelial cells inhibit coagulation?

Back 10

• Inhibits platelet activation
• Endo cells are highly negatively charged and so they repeal the negatively charged platelets
• Endos also produce thrombomodulin and heparin sulfate
• HS potentiates antithrombin III
• Both inhibit the action of thrombin

Front 11

Describe hemophila A

Back 11

A=ATE=EIGHT
--Deficiency of factor VIII
--X-linked disorder
--Individuals with deficiencies will suffer joint and muscle hemorrhage, easy bruising and prolonged bleeding from wounds

Front 12

Describe hemophila B

Back 12

--Deficiency of factor IX
--the prevalence is 1/10 that of A
--All patients with HB have a prolonged coagulation time and decreased factor IX clotting activity

Front 13

Describe Hemostatis? (Fibrinogen)

Back 13

Fibrinogen
--Several cardiovascular risk factors are associated with abnormalities in fibrinogen
--Elevated plasma fibrinogen levels have been observed in patients with CAD, diabetes, hypertension, peripheral artery disease, hyperlipoprteinemia, and hypertrigluceridemia
--Preggers, menopause, hypercholesterolemia, oral contraceptives, and smoking lead to increased plasma fibrinogen levels

Front 14

Hemostatis (Factor XIII)

Back 14

--Is the proenzyme form of plasma transglutaminiase and is activated by thrombin in the presence of calcium ions
---Hereditary deficiencies(autosomal recessive) occur resulting in the absence of either rsubunit
--Deficiency leads to neonatal umbilical cord bleeding, intra cranial hemorrhage and soft tissue hematomas

Front 15

What affects PTT?

Back 15

--Prekallikrein
--high molecular weight kininogen
--Factors XII,XI, IX, VIII
--And members of the common pathway II, V, X, & fibrinogen

Front 16

What effects PT

Back 16

--Tissue factor
--VII
--Coagulation factors in common pathway II, V, X, & Fibrinogen

Front 17

1) Describe the mechanism of activation of the extrinsic pathway

2) List the enzyme responsible for fibrin cleavage

Back 17

1) Trama causes VIIVIIa Which is cleavage of of the serine protease.

2) Fibrin is cleaved by plasmin
--Plasmin is a serine protease
--Zymogen-->plasminogen.
--APC in addition to turning of the blood coagulation cascade also stimulates the release of plasminogen activator from tissues.
--Plaminogen activator leads to plasmin formation

Front 18

How is fibrin stabalized by XIII?

Back 18

--Results in formation of hard clot
--Its presence results in the cross linking of fibrin monomers.
--Factor XIII is cleaved by Thrombin

Front 19

Discuss the role of Vit K in coagulation.

Back 19

1) Phylloquinone K1 is found in green leaves
2) Menaquinone K2 is made by intestinal bacteria
3) Humans convert Menadione K3 to vitamin K active form hydroquinone
4) Vitamin K is responsible for the carboxylation of pro-coagulation factors

Front 20

Blank

Back 20

Blank