PLATELETS

Question 1

Very fine and diffusely granular cytoplasm with irregular peripheral border

A. Megakaryoblasts
B. promegakaryocyte
C. granular megakaryocyte
D. mature megakaryocyte

Answer 1

Granular megakaryocyte
-30 to 90 um in diameter
- CYTOPLASM : Abundant, pinkish blue
Very fine and diffusely granular cytoplasm with IRREGULAR PERIPHERAL BORDER
- NUCLEI : Multiple may be visible or the nucleus may show MULTI LOBULATION
- N:C ratio is 2:1 to 1:1

Question 2

Cytoplasm contains coarse clump of granules aggregating into little bundles, which bud off from the periphery to become
platelets

A. Megakaryoblasts
B. promegakaryocyte
C. granular megakaryocyte
D. mature megakaryocyte

Answer 2

Mature megakaryocyte

• 40 to 120 um in diameter
• Cytoplasm contains COARSE CLUMP of granules aggregating into LITTLE BUNDLES, which bud off from the periphery to become platelets
• Nucleus is multilobulated
• N:C ratio is 1:1

Question 3

_____ of the platelets are on the circulation

A.2/3
B. 1/3
C. 1/2
D AOTA

Answer 3

2/3 of the platelets are on the circulation

1/3 of the platelets are found on the spleen

Question 4

On a Wright-stained wedge-preparation blood film, platelets are distributed throughout the red blood cell monolayer at ___________ cells per 100x field /OIF

A. 4-5 cells
B. 8-15 cells
c. 8-20 cells
d. 10-20 cells

Answer 4

• Each megakaryocyte produces between 2000 to 4000 platelets (Rodak’s), (1000-4000 Steinenger)
  
  • On a Wright-stained wedge-preparation blood film, platelets are distributed throughout the red blood cell monolayer at 8 to 20 cells per 100x field /OIF. (7 to 21 per OIF =RODAKS)
  • Life span of 8 to 11 days or 9 to 12 days. At the end of their life span, platelets are phagocytized by the liver and spleen and other tissues of the mononuclear phagocytic system.

Question 5

which of the ff platelet structure is composed of the membranes and is responsible for platelet adhesion and aggregation

a. peripheral zone
b. organelle zone
c. sol gel zone
d. membranous zone

Answer 5

Peripheral zone
– composed of the membranes and is responsible for platelet adhesion and aggregation

a. Glycocalyx
– OUTER surface, fuzzy coating, primarily composed of glycoproteins including coagulation factors V, VIII and fibrinogen.

b. Plasma membrane
- bilayer of asymmetrically distributed phospholipids

c. Submembranous area
- where MESSAGES from external membrane are translated into chemical signals causing activation and physical change in platelet

Question 6

which the peripheral zone is MESSAGES from external membrane are translated into chemical signals causing activation and physical change in platelet

a. glyocalyx
b. plasma membrane
c. submembranous area

Answer 6

Peripheral zone
– composed of the membranes and is responsible for platelet adhesion and aggregation

a. Glycocalyx
– OUTER surface, fuzzy coating, primarily composed of glycoproteins including coagulation factors V, VIII and fibrinogen.

b. Plasma membrane
- bilayer of asymmetrically distributed PHOSPHOLIPIDS

c. Submembranous area
- where MESSAGES from external membrane are translated into chemical signals causing activation and physical change in platelet

Question 7

There are _______ alpha granules in each platelet

A. 2-7
B. 50-70
C. 50-80
D. 10-90

Answer 7

There are 50 to 80 ALPHA granules in each platelet

2-7 DENSE granules per platelet

Question 8

maintains platelet disc shape

a. microfilaments
b. microtubules
c. mitochondria
d. alpha granules

Answer 8

Sol gel zone

1. MICROFILAMENTS ; actin and myosin
   protein for platelet contractile
2. MICROTUBULES : tubulin
   maintain platelet disc shape

Question 9

for energy production

a. microfilaments
b. microtubules
c. mitochondria
d. alpha granules

Answer 9

organelle zone

a. mitochondria
- for energy production / ATP synthesis

b. alpha granules
- platelet factor 4,plt derived growth factor, thrombospodin, vwf, fibrinogen, fibronectin , factor v. etch

c. dense granules
- Calcium, adp, pyrophosphate, atp, serotonin and magnesium

d. Lysosomal type granules (lysosome)
▪ Contains Acid hydrolases, ACP, and Hydrolytic enzymes

Question 10

which of the following does not belong to dense granules

a. calcium
b. adp
c. fibrinogen
d. pyrophosphate

Answer 10

dense granules (CAAPS M)
  Calcium
  adp
  atp
  pyrophosphate
  serotonin
  magnesium

answer: fibrinogen ( alpha granules)

Question 11

It is the “control center” for platelet activation

a. mitochondria
b. microfilaments
c. dense tubular system
d. surface containing canalicular system

Answer 11

Membranous system

1. Dense tubular system
   ▪ Derived from rough ER and sequesters or HOLD CALCIUM for platelet activation process and prostaglandin synthesis
   ▪ It is the “CONTROL CENTER” for platelet activation
2. Surface connecting canalicular system
   ▪ An invagination of plasma membrane, act as a CANAL FOR THE RELEASE OF GRANULES. Also involve in platelet phagocytosis
   ▪ Allows for ENHANCE INTERACTION of the platelets with its environment

Question 12

Appear in compensation for thrombocytopenia

A. CICULATING PLATELETS
B. RETICULATED PLATELETS
C. PROPLATELET PROCESS
D. THROMBOCYTOPOIESIS

Answer 12

> Circulating platelets - These are platelets found in the circulation and CAN BE COUNTED

> Reticulated platelets

        - Known as STRESS PLATELETS
        - Appear in compensation for thrombocytopenia 
        - They are larger than ordinary mature platelets 
        - ROUND UP  in EDTA, CYLINDRICAL AND BEASED in citrated blood 
         - They carry free ribosomes and fragments of rough E.R 
        - They are prothrombic, and may be associated with INCREASED RISK IN CARDIOVASCULAR DISEASE