Primary Hemostasis Flashcards
Platelets are referred to as ______.
Thrombocytes
Appearance of platelets in the PBS:
2-3 um
Small bluish
Granular structures
Discoid
What is the normal value of platelets?
150,000-450,000/uL
What is the process of creating platelets?
Thrombopoiesis
Platelets are derived from what?
Megakaryocytes
The MSC differentiates into _____ with the influence of hormnal growth factors
Megakaryocyte-colony-forming-units
What cell is known as the primitive cell during platelet development?
Megakaryoblast
What cell is in stage 1 of platelet development?
Megakaryoblast
Appearance of the megakaryoblast
15-10 um
Single, central nucleus
Diffuse-blue cytoplasm
What cell is in stage 2 of platelet development?
Promegakaryocyte
True or false:
Megakaryoblast is capable of protein synthesis
False
True or false:
Promegakaryocyte is capable of protein synthesis
True
What is developed further by invagination of the plasma membrane in stage 2 of platelet development?
Demarcating membrane system (DMS)
What cell is present in stage 3 during platelet development?
Granular megakaryocyte
What cell is present in stage 4 during platelet development?
Mature megakaryocyte
Platelets shed in groups are called _____.
Proplatelets
Each megakaryocte shed _____ platelets
1000-5000
What happens to the remaining cytoplasm and the nuclei after the megakaryocyte sheds?
Phagocytized by neighboring macrophages
Megakaryocytes shed how much platelets per day?
40-60
What is the primary factor of platelet release?
Thrombopoietin
Life span of platelets
2-10 days
What is the possible cause of larger platelets?
Severe bleeding
What is the possible cause of smaller than normal platelets?
Inflammation or IDA
What type of platelet are produced as compensation to thrombocytopenia?
Reticulated platelets / stress platelets
What part of a platelet gives it a sponge-like appearance?
Canaliculi
A platelet is divided into 4 major areas; what are these areas?
- Plasma membrane (peripheral zone)
- Submembrane area (membranous zone)
- Platelet cytoskeleton (sol-gel zone)
- Organelle zone
The surface coat in platelets
Glycocalyx
True or false:
The glyxocalyx provides a surface that lets coagulation factors adhere to the platelet
True
Modified true or false:
NaK ATPase ionic pumps and vWF are located in the membranous zone
False. Peripheral zone
What part of the platelet contributes to the regulation of the normal platelet?
Submembranous filaments
What part of platelets act as a base for pseudopod formation
Submembranous area / membranous zone
Platelet cytoskeleton is known as ____ zone
Sol-gel
Which zone maintains the resting shape of the platelet?
Sol-gel zone
What are the 3 types of granules present in the organelle zone of platelets?
Alpha granules
Dense granules
Lysosomal granules
Which granule inhibits heprin and with what molecule?
Alpha granules
Platelet factor 4
Thromboglobulin
What is the most important component of dense bodies?
ADP
The uptake and release of substances in platelets are facilitated by what component of the membrane?
Open canalicular systwm
Term that means “the stoppage of blood flow”
Hemostasis
What are the factors present in the extrinsic pathway?
FVII, FVIIA, FIII, FIIIA
What are the factors present in the intrinsic pathway?
FXII, FXIIA, FXI, FXIA, FIX, FIXA, FVIII, FVIIIA
What activates the FXII?
Kallikrein, HMWK, collagen
In what factor does intrinsic and extrinsic pathway meet?
FX
What are the factors from the intrinsic and extrinsic pathway that activates FX?
FIIIA, and FVIIIA & FIXA
What are the factors present in the common pathway?
FXIII, FXIIIa, FX, FXa, FV, FVa, FII, FIIa, FI, FIa
What factor is fibrinogen?
Factor 1
What factor is the glass factor?
Factor 12
What factor is calcium?
Factor 4
What factor is the tissue factor?
Factor 3
What laboratory test is used to evaluate the extrinsic and common pathway?
Prothrombin time test (PT)
What test is used to evaluate the intrinsic and common pathway?
Partial thromboplastin time test (PTT)
What are the substances that promotes coagulation? What produces those substances?
HMWK
Fibrinogen
Factor 5
vWF
- alpha granules
What may trigger the adherence of platelets to endothelial cells?
TF
collagen
fibrinonectin
thrombospondin
laminin
vitronectin
Platelet adhesion to collagen requires ___.
Von Willebrand Factor (vWF)
A platelet disease wherein the GP IB receptor is absent
Bernard Soulier Syndrome
A platelet disease that correlates to abnormal vWF glycoprotein
Vin Willebrand Disease
What is the treatment for vWD?
Cryoprecipitate
A condition where the GP IB-IIIA receptor is absent.
Glanzmann Thrombasthenia
What happens when the GP IIB-IIIA receptor is absent?
Platelet won’t be able to aggregate with the use of ADP, collagen, thrombin & arachidonic acid
The process whereby the temporary fibrin clot is systematically and gradually dissolved.
Fibrinolysis
What substance is capable of degrading fibrin?
Plasmin
A condition wherein the deficiency of a-granules causes lifelong bleeding tendency
Gray platelet syndrome
HMWK is also known as ____ factor
Fitzgerald factor
What type of sample is used for PTT test?
Platelet poor plasma
