Thrombocytes

Question 1

What is the normal range of platelets in the human body?

Answer 1

150,000- 400,000 in cubic millimetre

Question 2

Describe the physical charecteristrics of a platelet.

Answer 2

1. Small and discoid
2. Non-nucleated
3. Granulated
4. 2-4 micrometre in diameter
5. Blue staining outer region and inner area containing purplish granules.

Question 3

Why are the glycoproteins on the surface coat of the platelet important?

Answer 3

Glycoproteins on the outer surface of the platelets help in adhesion and aggregation to form platelet plugs.

Question 4

What receptors do the surface of platelets have?

Answer 4

1. Collagen
2. ADP
3. Fribrinogen
4. Von willebrand factor

Question 5

What does the cytoplasm of the platelets contain?

Answer 5

1. Lysosome
2. Actin
3. Myosin
4. Thrombostenin
5. Glycogen
6. Granules

Question 6

What do the granules in the platelets contain?

Answer 6

1. Seratonin
2. ADP
3. Platelet Derived Growth Factor (PDGF)
4. Calcium
5. Functioning mitochondria
6. Enzymes

Question 7

What do the enzymes systems in platelets do?

Answer 7

They produce:
1. Prostaglandins
2. Fibrin-stabilising Factor
3. Growth Factor

Question 8

What is the function of platelets?

Answer 8

1. Important in the formation of a platelet plug.
2. Release vasoconstrictors that cause cessel spasm.
3. Facilitate blood coagulation by releasing clotting factors such as platelet factor 3.
4. Clot retraction
5. Tissue repair by PDGF.

Question 9

What prevents the platelets from sticking to the endothelium lining?

Answer 9

The endothelium lining secretes:
1. Prostacyclin
2. NO

Question 10

Why are collagen receptors important on the platelets?

Answer 10

Binding of collagen during trauma causes the platelets to release platelet factors which attract more platelets and form a platelet plug.

Question 11

Why is fibrin stabilising factor important?

Answer 11

It maintains the covalent bonds between the fibrin so that the clot stays intact.