LEC1 - PLATELET PRODUCTION, STRUCTURE AND FUNCTIONS Flashcards
do platelets have nucleus?
nope, they are anucleated
platelets circulate at a concentration of ___
150-400 10^9/L
- Platelet count in women is slightly __________ than in men.
higher
Platelet count older than 65 years ________________.
lower
platelet triggers what type of hemostasis
primary hemostasis
Platelets arise from a unique bone marrow cell called ___
megakaryocytes
platelet life span
8 - 9 days
what is the largest cell in the bone marrow
megakaryocytes
megakaryocyte posses multiple chromosomes copies called as
polypoid
Megakaryocytes is about ___________
um in diameter
30 - 50 mm
megakaryocyte
It is the only cell line where cells become
bigger as they mature.
true or false
true the fire
Instead of mitosis, megakaryocytes undergo what type of cell division
endomitosis
what’s the difference of endomitosis to mitosis
A form of mitosis wherein there is no cytoplasmic division but there is NUCLEAR DIVISION
3 STAGE OF PLATELET PRODUCTION
- proliferative stage
- terminal differentiation stage
- thrombopoiesis stage
3 stages of megakaryocyte progenitors
BFU - burst forming unit
CFU - colony forming unit
LD - CFU - light density colony forming unit
the 3 stages of megakaryocyte progenitors are always thought and looks like as
lymphocytes
among the 3 stages of megakaryocyte progenitor, which are the ones undergoing mitosis and endomitosis
BFU and CFU undergo mitosis
LD - CFU undergo endomitosis
stages under proliferative stage of platelet production
BFU - burst forming unit
CFU - colony forming unit
LD - CFU - light density colony forming unit
stage of meg progenitors that clones hundreds of colony
Burst forming unit
stage of megakaryocyte that forms daughter colony
colony forming unit - cfu
the most matured stage of megakaryocyte progenitors
light density colony forming unit
the replication of
chromosomes in the
absence of cell
or nuclear division,
Endomitosis
stages of terminal
megakaryocyte differentiation
megakaryoblast
promegakaryocyte
megakaryocyte
precursor % of megakaryoblast
20%
megakaryoblast is also known as
MK I
Diameter of MK I
14-18 um
Nucleolus shape of MK 1
round
serotonin in d granules serve as a vasoconstrictor of what?
endothelial cells and plasma membrane
how many nucleoli are found in MK I
2-6
describe the chromatin of MK 1
homogenous
n:c ratio of MK 1
3:1
describe the color of cytoplasm of MK1
dark blue - basophilic - due to presence of RNA
% of precursor of MK II
25%
diameter of MK II
15-40 um
hallmark of MK II
has cleavage or indentation
do MK I has blebs?
yes ofcors
Cytoplasm of MK II
Basophilic and granular
% Precursor of MK III
56%
Diameter of MK III
30-50 um
Nucleolus of MK III
multilobed
Nucleoli of MK III
Not visible
Nucleolus of MK II
indented
Nucleoli of MK II
variable
Chromatin of MK II
condensed
N:C ratio of MK II
1:2
Nucleoli of MK III
not visible
Chromatin of MK III
Deeply condensed
N:C ratio of MK III
1:4
Cytoplasm of MK III
Azurophilic and
granular
Least differentiated megakaryocyte precursor
MK 1
do MK 1 still looks like LYMPHOCYTES?
No longer looks like LYMPHOCYTES
what stage of meg precursor Begins to develop most of its cytoplasmic ultrastructure
MK 1
what are the example of cytoplasmic ultrastructure
a granules
d granules
DMS - demarcation system
stage of megakaryocyte precursor where Nuclear lobularity ( INDENTATION) takes place
MK II
among the megakaryocyte precursor, this one is the most abundant and can be easily recognized. It is as well the one that sheds platelets
megakaryocytes
divides the
cytoplasm into
small platelet
territories
DMS
a process of platelet releasing is called as
thrombocytopoiesis
- During thrombocytopoiesis, a single
megakaryocyte may shed
_________ platelet
2000 - 4000 platelets
a hormone or a growth fatctor that will stimulate the production of platelets
TPO - thrombopoietin
a stage of platelet production wherein a Shedding of platelet or shedding of
megakaryocyte takes place
thrombopoiesis stage
a ultrastructure of platelet which is a future site of fragmentation
DMS - demarcation system
a series of membrane lined channel. It will
invade from the plasma membrane and it will
grow inward to subdivide the entire cytoplasm. It
is identical to megakaryocyte plasma membrane
DMS - demarcation system
a cytoplasmic ultrastructure of platelet that is present in all stages of Meg precursor (MK I, II , III) and is main purpose is for adhesion
a-granules/ alpha granules
a condition or disease associated to lack of alpha granules is called as
Gray platelet syndrome
platelet’s size
2-4 um
color and appearance of platelet
pale blue cells with azurophilic granules
normal MPV of platelet
MPV : 8-10 fl
Shape of platelet
Disk-shaped or circular to
irregular lavender and granular under
wright stained wedge preparation
Reference value of platelet
150-400 x 10^9 /L
how many percent of platelet constitute the body’s circulation?
70%