Lesson 3: CELL STRUCTURE OF MATURE PLATELET, PLATELET KINETICS Flashcards
It is also known as a “Fluffy coat”
Glycocalyx
these surrounds the cellular membrane of the
platelet externally.
Glycocalyx/Fluffy coat
It is unique among the cellular components of the blood.
Glycocalyx
It is composed of plasma proteins and carbohydrate molecules that are related to the coagulation, complement, and fibrinolytic systems.
Glycocalyx
It provides structure of the platelet to maintain its discoid shape
MICROFILAMENTS & MICROTUBULES
Where are MICROFILAMENTS & MICROTUBULES located?
located directly beneath the cell membrane of platelet
maintains the position of the organelles
Microfilaments and microtubules
Cellular Structure of a mature platelet is composed of what?
Granules and Other cytoplasmic constituents
What are the OTHER CYTOPLASMIC CONSTITUENTS of a mature platelet?
Contractile proteins, Glycogen, and Enzymes of the glycolytic and hexose pathways
What is the most abundant granule?
Alpha Granules
What does Alpha Granules contain?
HVPPFBT
- Heparin-neutralizing platelet factor 4 (PF4)
- beta-thromboglobulin
- platelet-derived growth factor
- Platelet fibrinogen
- fibronectin
- von Willebrand factor (vWF)
- thrombospondin
Delta granules are also known as…
Dense granules
Delta granules contain…
CASA
- Calcium
- ADP
- Serotonin
- ATP
These store hydrolase enzymes
Lysosomes
Contractile proteins include what?
actomyosin, myosin, and filamin
actomyocin is also known as
thrombosthenin
How many platelets does an average megakaryocyte produce?
1000 to 2000 platelets
What is the marrow transit time / maturation period of megakaryocytes?
FIVE DAYS
Platelets initially enter what organ?
The spleen
Platelets initially enter the spleen & remains for how many day/s?
2 days
Platelets are in either the _________ or the __________?
circulating blood, active splenic pool
Approximately 2/3 of the total number of platelets are in the spleen that free exchange with the general circulation
True or False
FALSE
in the SYSTEMIC CIRCULATION
The remaining 1/3 exists as pool of platelets in the spleen that free exchange with the general circulation
True or False
TRUE
A normal person has an average of how many platelets in the systemic circulation?
250 × 10^9/L
150 ×10^9/L to 450 × 10^9/L
The lifespan of a mature platelet is…
9.0 days ± 1 day.
Platelet turnover or effective thrombopoiesis averages…
35 ×
10^9/L ± 4.3 × 10^9/L/day
What happens to platelets at the end of their lifespan?
platelets are phagocytized by the
liver and spleen and other tissues of the mononuclear phagocytic
system