Alternative name for Platelets
Thrombocytes
Characteristic of Thrombocytes
Non-nucleated blood cells
Size of Platelets
2.5 um
Normal value of Platelets
150 - 400x10^9 fL
Normal volume of Platelets (MPV)
8 - 10 fL
Location of platelets in the body
30% in Spleen
60% in blood circulation
Origin of Platelets
Megakaryocytes
Largest cell in the bone marrow
Megakaryocytes
Size of Megakaryocytes
30-50 um
Term for the production and development of megakaryocytes
Megakaryocytopoiesis
Where does Megakaryocytopoiesis occur?
Bone marrow
What is the origin of blood cells?
Hematopoietic Stem Cell
Unique characteristic of Hematopoietic Stem Cell
Can undergo self-renewal, differentiation, or apoptosis
Major growth factor of Megakaryocytopoiesis
Thrombopoietin
Enumerate the 3 phase of Megakaryocytes
Proliferative phase
Terminal differentiation
Platelet shedding
Proliferative phase AKA
Progenitors
Terminal differentiation AKA
Morphologically Identifiable Stage
Platelet shedding AKA
Thrombocytopoiesis
What does GEMM stand for?
Granulocyte
Erythrocyte
Monocyte
Megakaryocyte
Form of mitosis that lacks telophase and cytokinesis
Endomitosis
Enumerate the major progenitor stages of Proliferative phase
BFU-Meg
CFU-Meg
LD-CFU-Meg
BFU-Meg (Least Mature)
Burst Forming Unit-Megakaryocyte
CFU-Meg
Colony Forming Unit-Megakaryocyte
LD-CFU-Meg (Most Mature)
Low Density-Colony Forming Unit-Megakaryocyte
Methods of Identification for Progenitors
Immunologic tests
Cytochemical stains
Immunologic tests AKA
Flow Cytometry
What does MK 1 (I) Stand for in Terminal Differentiation?
Megakaryoblast
What does MK 2 (II) Stand for in Terminal Differentiation?
Promegakaryocyte
What does MK 3 (III) Stand for in Terminal Differentiation?
Megakaryocyte
What stage does Endomitosis end?
MK-II or Promegakaryocyte
How many Platelets can MK-III produce?
2000-4000
Megakaryocyte marker that is present in all the stages of Megakaryocytopoiesis
MPL
What hormone induces stem cell differentiation?
Thrombopoietin
Which Cytokine/Hormones can be used for Therapy
TPO, IL-11 (Interleukin 11)
Maturation time of Megakaryocytes in the Bone Marrow
5 days
Survival/Lifespan of Platelets in circulation
8-9 days
Appearance of Platelets
Biconvex
What platelets carry free ribosomes and fragments of rough ER?
Stress Platelets
Alternative name for Stress platelets
Reticulated platelets
Size of Stress platelets
6 um
Normal volume of Stress platelets
12-14 fL
Unique characteristic of Stress platelets
Constains residual RNA
Method of detection of Stress platelets
Flow cytometry
Dye used in Flow cytometry for identification of Stress platelets
Thiazole orange
Composition of Plasma membrane of PLT
Proteins, Lipids
Platelet's outer membrane surface
Glycocalyx
Thickness of Glycocalyx
20-30 nm
Electric charge of Glycocalyx
Negative (-)
Mode of absorption of albumin, fibrinogen and transports them to storage organelles in Platelets
Endocytosis
Unique characteristic of Glycocalyx
Adhesive
What system maintains a direct communication with the extracellular environment?
Surface-Connected Canalicular System (SCCS)
What is the site for arachidonic acid metabolism within platelet?
Dense Tubular System
Control center for platelet activation
Dense Tubular System
Cytoskeleton that maintains the platelet shape
Microtubules
Composition of Microtubules
Tubulin
Cytoskeleton responsible for clot retraction
Microfilaments
Composition of Microfilaments
Actin, Myosin
What is the cause of platelet contraction?
Actin
Enumerate Platelet Granules
Alpha granules
Dense granules
Lysosomes
What platelet granule is present in the numbers between 50-80?
Alpha granules
Color of alpha granule in osmium dye
Gray
What is the disorder called when alpha granule contents are absent?
Gray platelet syndrome
Enumerate the ALPHA granule content
Fibrinogen
Von Willebrand Factor (vWF)
Factor 4 & 8
Platelet Factor 4
What alpha granule content neutralizes heparin?
Platelet factor 4
What platelet granule is present in the numbers between 2-7?
Dense granules
Color of Dense granule in osmium dye?
Black
Disorder for diminished Dense granule contents
Storage pool disorder
Organelle that contains enzymes needed for cellular cleaning and recycling of platelets
Lysosomes
What does Lysosomes stain positive with?
Arylsulfatase
B-glucuronidase
Acid phosphatase
Catalase
Functions of Lysosomes
Digest vessel wall matrix components during in vivo aggregation
Digest autophagic debris