BLOOD - Platelets

Question 1

29

Platelets are derived from what large Leukocyte?

Answer 1

Megakaryocyte

Multipotent hematopoietic stem cell
-hemocytoblast
Myeloid
Megakaryocyte
Thrombocyte

Question 2

30

Describe Thrombopoesis?

Answer 2

the production of platelets 
-hemopoietic stem cells
some produce receptors 
-thrombopoietin 
ligations (joining) of the cytoplasm
protein hormone stimulates megakaryopoiesis

Question 3

31
Describe 2 granules found in platelet cytoplasm?
What products are released?
What is the function of released products?

Answer 3

DENSE

ALPHA

Question 4

Dense granules release?

Answer 4

-ATP (ADP), calcium, serotonin

Question 5

Alpha Granules Release?

Answer 5

• P selectin
• platelet factor 4
• transforming growth factor
• platelet-derived growth factor
• fibronectin
• B-thromboglobulin
• vWF
• Fibrinogen
• Coagulation factors V and XIII

Question 6

P-selectin

Answer 6

protein
cell adhesion molecule
surface of endothelial cells

Question 7

Platelet Factor $

Answer 7

cytokine - signaling molecule
promotes blood coagulation
-platelet aggregation
-heparin (moderates effect)

Question 8

Transforming growth factor beta 1

TGF-B1

Answer 8

cytokine
secreted protein
-cell growth
-cell proliferation
-cell differentiation
-apoptosis (programmed cell death)

Question 9

Platelet derived growth factor

Answer 9

growth factor
protein
regulates cell growth and division

Question 10

Fibronectin

Answer 10

glycoprotein
extracellular matrix
binds to membrane receptor proteins 
-integrins
binds extracellular components
-collagen
-fibrin

Question 11

B - Thromboglobulin

Answer 11

Platelet basic protein
stored protein
released after platelet activation
chemokine ligand
-small cytokine 
stimulates
-mitogenesis - mitogen - stop cell division
-synthesis of extracellular material
-glucose metabolism
-synth plasminogen activator - protease promotes fibrinolysis - stops clot growth

Question 12

vWF

Answer 12

blood glycoprotein

-hemostasis - stop blood

Question 13

Fibrinogen

Answer 13

soluble glycoprotein
converted by thrombin into fibrin
-reduction of blood loss
-blood clotting non-globular protein

Question 14

Coagulation Factors V and XIII

Answer 14

Blood forms clots
V - protein
-not enzymatically active
-functions as a cofactor = helper molecules
deficiency predisposition for hemorrhage
predispose for thrombus

Question 15

XIII

Answer 15

enzyme
blood coagulation system
cross-links fibrin