Hemodynamics- platelets and coagulation

Question 1

What are platelets

Answer 1

cell fragments shed into the bloodstream by the bone marrow megakaryoctes.

Question 2

What’s the function of platlets

Answer 2

they form a hemostatic plug that seals vascular defects and by provide a surface that recruits and concentrates activated coagulation factors

Question 3

What do platelets function on

Answer 3

several integrins
a contractile cytoskeletion
two types of cytoplasmic granules

Question 4

What are the 2 types of granules of platelets

Answer 4

alpha-granules

dense bodies

Question 5

What is the function of alpha granules

Answer 5

express P-selectins on their membrane and contain fibrinogen,fibronectin, factor 5,7 and platelet factors 4, platelet derived growth fact and transforming growth factor

Question 6

What is the function of dense bodies

Answer 6

contains ADP, ATP, ionized calcium, histamine, serotonin, epinephrine

Question 7

What is the function of VWF

Answer 7

Functions in as adhesion bridge between the sub endothelial collagen and the glycoprotein Gplb platelet receptors

Question 8

How is platelet aggregation accomplished by

Answer 8

Fibrinogen binding to platelet glycoprotein complex (GpllB and IIIa)

Question 9

What are deficiencies with adhesion and aggregation

Answer 9

vWF- von willebrand disease
GpIb- Bernard-Soulier
GpIIb- IIIa- Glanmann thrombasthenia

Question 10

What is coagulation cascade

Answer 10

a successive series of amplifying enzymatic reactions. each step a substrate is protelozyed to becomes and active enzyme and which in turns proteolyses the next proenzyme

Question 11

What it TFPI

Answer 11

Tissue Factor pathway inhibitor that is a protein secreted by endothelium that inactivates factor Xa and tissue factor factor VIIIa complex

Question 12

What is antithrombin

Answer 12

inhibits the activity of thrombin and other serine proteases. activated by binding to heparin like molecules on endothelial cels

Question 13

What is the role of thrombin

Answer 13

it generate fibrin by cleaving fibrinogen, activates factor XIII, and activates other coagulation factors, thereby amplifying the coagulation cascade.

Question 14

What is the function of TxA2

Answer 14

a potent vasoconstrictor and stimulates platelet aggregation

Question 15

What is the function of PGI2

Answer 15

a vasodilators and inhibits platelet aggregation