3: Platelet production, structure, and function

Question 1

Maturation sequence of megakaryoblast takes about

Answer 1

5 days

Question 2

is the process in which
chromosomal material (DNA) and the other events of mitosis occur without subsequent division of the cytoplasmic membrane into identical daughter cells.

Answer 2

Endoreduplication

Question 3

Is a 70,000 dalton molecule that circulates as a hormone in plasma and is the ligand that binds the megakaryocyte and platelet membrane receptor protein, MPL

Answer 3

Thrombopoietin (TPO)

Question 4

Induces the proliferation and maturation of megakaryocytes and induces thrombocytopoiesis

Answer 4

Thrombopoietin (TPO)

Question 5

Primary source of Thrombopoietin

Answer 5

Liver

Question 6

Act in synergy with TPO to
induce the early differentiation of stem cells

Answer 6

Interleukin-3

Question 7

Acts in the presence of TPO to enhance endometriosis, megakaryocyte, maturation, and thrombocytopoiesis.

Answer 7

Interleukin-6 & Interleukin-11

Question 8

Three megakaryocyte lineage-committed progenitor stages arising from common myeloid progenitor:

Most primitive progenitor cell committed to megakaryocyte lineage

Answer 8

BFU-Meg

Question 9

Three megakaryocyte lineage-committed progenitor stages arising from common myeloid progenitor:

Hundreds of colonies

Answer 9

BFU-Meg

Question 10

Three megakaryocyte lineage-committed progenitor stages arising from common myeloid progenitor:

least mature

Answer 10

BFU-Meg

Question 11

Three megakaryocyte lineage-committed progenitor stages arising from common myeloid progenitor:

Dozens of colonies

Answer 11

CFU-Meg

Question 12

Three megakaryocyte lineage-committed progenitor stages arising from common myeloid progenitor:

Cannot divide but it retains DNA replication and cytoplasmic maturation for endomitosis

Answer 12

LD-CFU-Meg

Question 13

Three megakaryocyte lineage-committed progenitor stages arising from common myeloid progenitor:

more mature progenitor

Answer 13

LD-CFU-Meg

Question 14

Sequence of development from megakaryocyte to platelets:

Answer 14

Proliferation of progenitors to polypoidization
Nuclear endoreduplication
Cytoplasmic maturation
Formation of platelets

Question 15

Is a form of mitosis that lacks telophase and cytokines (separation into daughter cells)

Answer 15

Endomitosis

Question 16

Partially characterized form of mitosis unique to megakaryocytes in which DNA replication and cytoplasmic maturation are normal but cells lose their capacity to divide.

Answer 16

Endomitosis

Question 17

MK-I stage or Megakaryoblast Cannot be reliably distinguished from bone marrow

Answer 17

myeloblasts or pronormoblasts

Question 18

Terminal megakaryocyte differentiation:

Vague clue: plasma membrane blebs

Answer 18

MK-I stage or Megakaryoblast

Question 19

Terminal megakaryocyte differentiation:

Least differentiated precursor

Answer 19

MK-I stage or Megakaryoblast

Question 20

Begins to develop most of its cytoplasmic ultrastructure, including procoagulant-laden a-granules, dense granules, and demarcation system

Answer 20

MK-I stage or Megakaryoblast

Question 21

Is a series of membrane-lined channels that invade from the plasma membrane and ultimately delineates the individual platelets during thrombocytopoiesis

Answer 21

DEMARCATION SYSTEM

Question 22

Is biologically identical to the megakaryocyte plasma membrane

Answer 22

DEMARCATION SYSTEM

Question 23

Nuclear lobularity first becomes apparent as an indentation at the 4N replication stage

Answer 23

MK-II stage or Promegakaryocyte

Question 24

Vague clue: Indentation in the nucleus

Answer 24

MK-II stage or Promegakaryocyte

Question 25

The most abundant

Answer 25

MK-III stage or Megakaryocyte

Question 26

Are the largest cells in the bone marrow and possess multiple chromosome copies

Answer 26

MK-III stage or Megakaryocyte

Question 27

MK-III stage or Megakaryocyte size in diameter

Answer 27

30-50 um

Question 28

Nucleus is intensely indented or lobulated

Answer 28

MK-III stage or Megakaryocyte

Question 29

Distinctive feature: it is not multinucleated

Answer 29

MK-III stage or Megakaryocyte

Question 30

A single megakaryocyte may shed to

Answer 30

2000 to 4000 platelets

Question 31

platelet lifespan

Answer 31

8 to 9 days

Question 32

concentration of platelets

Answer 32

150-400 x 10^9/L

Question 33

Average diameter of platelet

Answer 33

2.5 um

Question 34

MPV of platelet:

Answer 34

8-10 fL

Question 35

Resting platelets are

Answer 35

biconvex

Question 36

Platelets are produced directly from the

Answer 36

megakaryocyte cytoplasm

Question 37

platelets on the circulation

Answer 37

⅔

Question 38

platelets found on the spleen

Answer 38

⅓

Question 39

The platelet is composed of about

Answer 39

60% protein, 30% lipid, 8% carbohydrate, various mineral, water, and nucleotide

Question 40

Sometimes known as stress platelets, appear in compensation for thrombocytopenia

Answer 40

Reticulated Platelets

Question 41

Are markedly larger than ordinary mature circulating platelets

Answer 41

Reticulated Platelets

Question 42

Size of Reticulated Platelets in diameter

Answer 42

6 um

Question 43

MPV of Reticulated Platelets

Answer 43

12-14 fL

Question 44

Carry free ribosomes and fragments of rough endoplasmic reticulum

Answer 44

Reticulated Platelets

Question 45

Stain for Reticulated Platelets

Answer 45

Nucleic acid dye (Thiazole Orange)

Question 46

Stain for Reticulocytes

Answer 46

Supravital stain (New Methylene Blue)