Platelets Flashcards
___ are small colourless and non-nucleated blood cells
Platelets
Platelets are ___ or ___ shaped when active
Spherical or Rod
Platelets are___ or ___ shaped when inactivated
Oval or Disc
Platelets are __ micrometers in diameter
1 to 4
Platelets have a life span of ____ days
8-12
___ is the production of platelets
Thrombopoiesis
Rate of platelet formation is stimulated by ____, ____, ____ & ____
Thrombopoeitin
Thrombocyte-stimulating factor
Interlukin-11 &
Multi_CSF
The platelet cell membrane is___ thick
6nm
Platelet cell membrane contains?
Lipids(phospholipids, glycolipids, cholesterol)
Carbohydrates(glycocalyx)
Proteins
Glycoproteins
Some functions of glycoproteins in platelet cell membrane are?
Forms a receptor for ADP and thrombin
Accelerates
the adherencee of platelets to collagen and damaged endothelium
Some functions of platelets are?
Transporting chemicals important to clotting
Blood clotting
Transports PAF & PDGF
____ is a biological process that stops bleeding
Blood clotting/coagulation
The functions of clotting are to?
Prevent us from bleeding to death
Protect us from the entry of bacteria and viruses
Clots are made from fibers of a protein called?
Fibrin
The process through which bleeding is stopped is called?
Haemostasis
The objects of haemostasis are to?
Maintain blood composition & fluidity
Restore normal vascular structure
Stem blood loss
Haemostasis is divided into?
Primary haemostasis
Secondary haemostasis
Tertiary haemostasis
Primary haemostasis is dependent on normal platelet ___ and ____
Number and function
___ is carried out during primary haemostasis
Platelet plug formation
The two processes carried out during secondary haemostasis are?
Activation of clotting cascade &
Deposition & Stabilization of Fibrin
Tertiary haemostasis is dependent on?
Plasminogen Activation
____ is carried out during tertiary haemostasis
Dissolution of Fibrin clot
The three mechanisms that work together to stop blood flow are?
Vasoconstriction
Platelet plug formation
Blood clotting
____ of a damaged blood vessel slows blood flow
Vasoconstriction
Vasoconstriction is mediated by?
Local controls
Systemic controls
Release of vasoconstrictors at the injury site like thromboxane is?
Local controls
Release of hormones like epinephrine from adrenal glands which stimulate vasoconstriction is?
Systemic controls
Platelet plug formation results from?
Platelet aggregation
In coagulation cascade, which clotting factors are found in the intrinsic system?
XII XI IX VIII X V II XIII IV I
In coagulation cascade, which clotting factors are found in the extrinsic system?
VII
III
Clotting factor 12 activates?
Clotting factor 12a
Clotting factor 12a activates?
Clotting factor 11
Clotting factor 11 activates?
Clotting factor 11a
Clotting factor 11a activates?
Clotting factor 9
Clotting factor 9 activates?
Clotting factor 9a and clotting factor 8a
Clotting factor 9a and clotting factor 8a together with clotting factors 7a & 3 from the extrinsic pathway activates?
clotting factor 10
clotting factor 10 activates?
clotting factor 10a and clotting factor 5a
clotting factor 10a and clotting factor 5a activates?
Clotting factor 2
Clotting factor 2 activates?
Thrombin
Thrombin activates?
Clotting factor 1 and clotting factor 13
clotting factor 13 activates?
Clotting factor 13a
Clotting factor 1 activates?
Fibrin
Clotting factor 13a and fibrin bring about?
A stable fibrin clot
Clotting factor 7 activates?
Clotting factor 7a & 3
Clotting factor 1 is also known as?
Fibrinogen
Clotting factor 2 is also known as?
Prothrombin
Clotting factor 3 is also known as?
Tissue factor[TF]/thromboplastin
Clotting factor 4 is also known as?
Ca2+
Clotting factor 5 is also known as?
Proaccelerin
Clotting factor 7 is also known as?
Proconvertin
Clotting factor 8 is also known as?
Antihemophilic A factor
Clotting factor 9 is also known as?
Antihemophilic B factor/Christmas factor
Clotting factor 10 is also known as?
Stuart or Stuart-Prower factor
Clotting factor 11 is also known as?
Plasma thromboplastin antecedent
Clotting factor 12 is also known as?
Hageman factor/contact factor
Clotting factor 13 is also known as?
Fibrin stabilizing factor
Prekallikrein factor
High-molecular weight kininogen
The extrinsic pathway is triggered by?
Tissue factor (chemical released from damaged cells)
The intrinsic pathway is triggered by?
Blood coming into contact with collagen fibres in blood vessels
The intrinsic pathway is also called?
Contact activation pathway
The system whereby temporary fibrin clots are systematically and gradually dissolved as the blood vessel heals is called?
Fibrinolysis
Inactive plasminogen is converted to active ___ in fibrinolysis
Plasmin
____ breaks down fibrin clots
Plasmin
The function of fibrinolysis is to prevent?
Occlusion of blood vessels
Physiologic inhibitors of coagulation are?
Antithrombin III
Activated Protein C + Protein S(inactivates factors Va & VIIIa) via proteolysis
Thrombomodulin(glycoprotein) etc
Thrombomodulin(glycoprotein) binds to ___, decreases ability to produce ___ and increases ability to activate ___
Thrombin
Fibrin
Protein C
Three bleeding disorders causes are?
Haemophilia A
Haemophilia B
Vitamin K Deficiency
Haemophilia A and B are ___ disorders, limited to males
X-linked
Vitamin K is essential to the maturation of several clotting factors like?
Clotting factor 10 and 2
Bleeding disorders are diagnosed by?
Clotting time
Bleeding time
Platelet count
Platelet aggregation studied