Path 1 Quiz 4 Flashcards
What term means “the stoppage of blood loss”?
Hemostasis
What is the principle mechanism of hemostasis?
Blood coagulation
What is a blood clot?
A mesh of protein filaments that traps blood formed elements to form a red, gelatinous mass
*this is a major killer in the united states
Define Fibrin Threads
Define Fibrinogen
Fibrin Threads: Threads that holds the blood cells together and they seal the wound to prevent losing of blood
Fibrinogen: Creates Fibrin strands
Clotting factors
- what are they, produced where?
- when are they inactive/active
- Vitamin most closely related?
- Are a set of PROTEINS produced in the liver
- Inactive in the blood circulation
- They are activated up injury through the extrinsic and intrinsic pathways, in the formation of a clot
- Vitamin K plays a key role
Clotting Factor I
Fibrinogen
Clotting Factor II
Prothrombin
Clotting Factor V
Preaccelerin
Clotting Factor VII
proconvertin
Clotting Factor IX
Christmas Factor
Why is clotting factor IX named what is it named?
Because “Christmas” was first described in a pt. with this name
Clotting factor X
Stuart Prower Factor
Clotting Factor XI
Plasma Thromboplastin antecedent
Clotting Factor XII
Hageman Factor
Clotting Factor XIII
Fibrin Stabilizing factor
What are the two ways blood clots are formed?
1) Blood Clot cascade
2) Platelet Activation
Which process of blood clotting involves fibrin strands?
Blood clot cascade
Fibrin Strands are made out of
protein fibrinogen (5 - 7% of all blood proteins)
In order to activate clotting factor 1 (fibrinogen), we need to activate
Clotting factor X (Stuart Prower Factor )
What are the two pathways of the Blood Clot Cascade? Where does each pathway happen?
- Extrinsic pathway: can happen in blood vessels and outside blood vessels
- Intrinsic Pathway: only develops within the blood vessels
Explain the Extrinsic pathway of the Blood Clot Cascade?.
- AKA for “Tissue Factor”
- Where does this occur - what cells?
- what is “tissue factor” released from?
- What clotting factors are involved
- What clotting factor activates another clotting factor
Tissue factor AKA Tissue Thromboplastin
Released from damaged cells, both injured blood vessels cells and injured tissue cells - these activate clotting factors
Tissue factor activates proconvertin (CFVII), proconvertin then activates stuart prower factor (CF X)
Explain the sequence of events for the Intrinsic Pathway?
Where does this occur?
- The inner layer of blood vessels are covered by endothelial cells - if there is a scratching of endothelial cells there is exposure of collagen fibers of SUBendotheial cells - they are exposed to blood flow and the clotting factor is then activated
- This only occurs INSIDE injuries blood vessels
- Exposure of collagen fibers to blood flow activates CF XII (HANGMAN FACTOR ) - this will activate Factor IX (Christmas) - which will then activate clotting factor X (stuart Power)
The clotting cascade that results in both ways is
Activation of clotting Factor X - Stuart Power —>
Activation of prothrombin clotting factor II —>
Leads to thrombin formation —>
Activation of fibrinogen Clotting Factor I —>
Leads to Fibrin formation
T/F The Intrinsic pathway and the Extrinsic pathway can occur simultaneously
True
What clotting factor needs to be activated in order to form fibrin?
Clotting Factor I (fibrinogen)
Explain the formation of fibrin strands that leads to coagulation?
Clotting factor X Activates prothrombin Activates thrombin Thrombin results in the activation of fibrinogen Fibrinogen transforms into fibrin Fibrin turns into fibrin strands leads to coagulation
What ion is essential for coagulation to occur?
- clinically what would someone with severe blood loss receive?
Ca++
Necessary component of coagulation - with out it it can not occur
Patients with severe blood loss are given “calcium CL” injection to help with blood clotting - INTRAvenously - if injected intravenously it would injury the tissues and cause tissue necrosis
Explain the sequence of Platelet activation process:
- What is the result of an activated platelet?
- Where does it occur?
- Exposure of collagen fibers (sub endothelial cells) to blood flow
- Von Willebrand Factor becomes activated and then attaches tot eh exposed collagen fibers (circulates in blood in inactive form until exposed to exposed collagen)
- Von Hillebrand Factor stops the flow of blood plate movement
- Platelets bind to Von Willebrand Factor, and form a single layer on top of the exposed collagen
- Once there is prevention of platelet blood flow by VW, the platelets become activated and then attach a second layer of platelets, etc - they continue to build on top of each other
- Platelet activation results in the formation of “platelet plug” - physically blocks the damaged blood vessel
- could be potential bad when there is no danger in losing of the blood
- Platelet activation ONLY occurs INSIDE blood vessels
Von Willebrand Factor
- what is it
- where is it located
- How is it activated
This is separate from clotting factors it is in the blood circulation like blood proteins - this is its inactive form
-Inactive Von Willebrand factor is attached to the wall in the area of the exposure of the collagen fibers to the collagen fibers - this is what activates it
What stops the physical flow of blood?
Platelet activation - “Platelet plug” and Coagulation (blood clotting via CF cascade)
When there is platelet activation there is platelet _________.
degranulation (granules open)
What is released during platelet degranulation / activation? What is each one of their roles?
1) ADP: stimulates further activation of platelets, potentiates the platelet response (they become more activated)
2) Thromboxane A2 = TxA2: functions to perform VASOCONSTRICTION (narrowing of the lumen, not allowing the blood to be lost) It also promotes platelet activation (coagulation)
3) Growth Factor: attracts fibroblasts (fibroblast chemotaxis) - so when there is injury and danger of losing blood the body needs to take care of healing - wound healing
What are fibroblasts?
What are their function?
- They are the source of components of CT
- These are the cells that go into the area of injury and produce pro collagen and glue
- Material for adhesions of the collagen filament to make collagen fibers and bundles
- FB also produce ground matrix (this is the glue substance)
Glue Substance is made by
Fibroblasts
What is the function and what are the three components of the anticoagulation system?
Maintains balance within the body - prevents EXCESS or uncontrolled blood clotting
1) Hemodynamics
2) Endothelial mediation
3) Fibrinolytic System
Explain what hemodynamics is?
Speed of blood flow
The different speeds of blood flow in different blood vessel is important for movement of blood
Slow blood flow is important for blood coagulation - otherwise activated Clotting Factors get washed out and a clot can not be formed
What is the hemodynamics of arteries? veins?
Arteries = fast Veins = slow
What is the challenge in forming a clot in an artery?
Because the hemodynamics of the arteries are fast paced - they clotting factors are immediately washed out not allowing the blood to stop flow and form a clot
The only way to stop bleeding in artier is mechanical blood pressure
Explain Endothelial mediation?
The wall of the blood vessel is covered by endothelial cells
Injury occurs to the endothelial tissues and platelet plug is formed BUT
Uninjured endothelial cells release PG12 (prostacyclin) which prevents extra or excess platelet aggregation
- this could potential prevent blood clot
PG12
- common name?
- Place of production
- Function
- Where is it released from?
- Prostacyclin
- Endothelial Cells
- Prevents the formation of the blood clot - prevents excess/extra platelet aggregation - stops wide spread coagulation in the body
- Only released from the ENDS of the damaged areas (where the damaged area ends and becomes undamaged area)
Explain the Fibrinolytic System
Tissue plasminogen activator is released from damaged tissue of the same endothelial cells
- This activates inactive plasminogen - Clotting factor 12
- Plasminogen FACTOR, converts plasminogen into PLASMIN
- Plasmin causes degradation of clotting factors and stops the formation of too much coagulated blood
What is Tissue Plasminogen Factor
-What is its main function?
Enzyme that degrades plasma proteins (fibrin)
- To stop the formation of too much coagulated blood
- It is an important fighter of thrombus which is the major cause of cardiovascular deaths
What strengthens fibrinolytic activity?
Physical activity
What are the different types of hemorrhages? (types of bruises)
- Petechiae Rash
- Purpura
- Ecchymosis
- Hematoma
Which hemorrhage is 2 cm in diameter (larger than a pinpoint) and occurs in Henoich-Schonen Disease?
Purpura Rash
Which hemorrhage is pin point bleeding and often occurs in scurvy? What vitamin are they deficient in?
Petechiae Rash
Vitamin C
Which hemorrhage is AKA bruise - is more than 2 cm in diameter - can occur in periorbital hemorrhage?
Examples
Ecchymosis
- Raccoon sign
- Battle sign
Ecchymosis can easily occur in what autoimmune disease?
-Why does this occur in this syndrome?
Cushing’s Syndrome
- over production of corticosteroids (cortisol) from the adrenal cortex
- leads to extremes brittleness of blood vessels - even small impacts can result in bruises
- if you have pt.s with cushing’s syndrome you must explain to them that if they have bruises after an adjustment that you are not hurting them
What is Cushing’s Syndrome?
- What causes it?
Overproduction of corticosteroids by the adrenal cortex (hyperplasia)
- the amount of cortisol is equal to the amount of corticosteroids produced
Can be caused by adenoma of the adrenal cortex or carcinoma of adrenal cortex
List the characteristics of Cushing Syndrome
Brittle blood vessels Systemic or severe osteoporosis Diabetes High Blood Pressure Moon face buffalo hump thin skin red striae Red cheeks Very high brusiability poor wound healing redistribution of fat is very obvious (moves from butt and back to the face (moon face) stomach (pendulous abdomen) and upper back (buffalo hump)