Blood 7

Question 1

What are the two main types of Granules found in Platelets?

Answer 1

Alpha granules and dense granules

Question 2

What do Alpha Granules generally contain?

Answer 2

Large molecules:
•Adhesion molecules
•Some clotting factors
•Growth factors
•Cytokines

Question 3

What do Dense Granules of Platelets usually contain?

Answer 3

Small molecules:
•ADP and ATP
•5-hydroxytryptamine (5HT or serotonin)
•Ca2+

Question 4

What is the abbreviation for Adhesion molecules?

Answer 4

vWF

Question 5

What do Adhesion molecules do?

Answer 5

Allow things to stick together

Question 6

What is involved in the formation of a Platelet plug?

Answer 6

1. Adhesion
2. Activation
3. Aggregation

Question 7

What occurs in Adhesion of platelets?

Answer 7

They stick to the damaged vessel wall

Question 8

What occurs in Activation of platelets?

Answer 8

They change shape, express various receptors, and secrete various substances

Question 9

What occurs in the aggregation of platelets?

Answer 9

They stick to each other and form a plug

Question 10

Where does Platelet plug formation take place?

Answer 10

On the Lumen inside the blood vessels, where the blood is flowing

Question 11

What is the wall of the blood vessel closest to the blood made out of?

Answer 11

Endothelial cells

Question 12

What forms the inner lining of the blood vessels?

Answer 12

Endothelial cells

Question 13

What layer surrounds the endothelial cells of the blood vessels?

Answer 13

Subendothelium

Question 14

What does the Subendothelium contain?

Answer 14

Many structures, many molecules of connective tissue including collagen

Question 15

Where in the blood vessels is Collagen found?

Answer 15

In the subendothelial layer

Question 16

What is above the Subendothelial layer?

Answer 16

Layers of smooth muscle

Question 17

What initiates the formation of a Platelet plug?

Answer 17

The exposure of collagen in the subendothelial layer of a blood vessel

Question 18

What occurs after collagen is exposed to the blood when a blood vessel is damaged?

Answer 18

Platelets stick to the collagen through an intermediary molecule called Von Willebrand (vWF)

Question 19

How do platelets stick to collagen?

Answer 19

Through an intermediate molecule called Von Willebrand factor (vWF)

Question 20

What is vWF produced by?

Answer 20

Platelets and Endothelial cells

Question 21

What does vWF do?

Answer 21

Binds platelets to collagen

Question 22

What happens once Platelets bind to Collagen?

Answer 22

The platelets become activated and expose various receptors

Question 23

What do the receptors on Platelets allow it to bind to?

Answer 23

Plasma proteins called fibrinogen

Question 24

What does Fibrinogen allow when it binds to platelets?

Answer 24

It allows more platelets to stick to the first ones that stuck to the vWF

Question 25

What is the order of clotting with platelets in a blood vessel?

Answer 25

Platelets stick to vWF which binds to collagen, and then another later of platelets that bind to the first layer and then more platelets on top of that

Question 26

What can be secreted by Activated Platelets?

Answer 26

• 5HT
• TXA2
• ADP
• PL

Question 27

Which substances secreted by platelets cause Vasoconstriction?

Answer 27

5HT and TXA2

Question 28

Which substances secreted by platelets causes further platelet aggregation?

Answer 28

• TXA2
• ADP
• Pl ➡️ Thrombin

Question 29

Which substance secreted by platelets causes both Vasoconstriction and Further platelet aggregation?

Answer 29

TXA2

Question 30

What is TXA2 supported by when it causes further platelet aggregation?

Answer 30

ADP and the presence of phospholipids on the surface of platelets