Patho Exam 1 Flashcards
Hemostasis is…
Blood’s ability to clot blood (clot formation at the site of injury)
Clotting depends on 3 factors… (3 steps to clotting success!)
Vascular - local vasoconstriction
Platelet - formation of platelet plug, platelet adhesion, & aggregation (white clot)
Coagulation factors - formation of blood clot (red clot); helps form a stronger clot to promote healing and prevent reopening of injury site
What are the 4 steps in the functional response of activated platelets?
Adhesion
Aggregation
Secretion
Procoagulant activity
Describe the adhesion phase in the functional response of platelets.
Deposition of platelets on subendothelial matrix in the area of the wound. Adhesion occurs on the edges of the wound
Describe the aggregation phase in the functional response of platelets.
Platelet-platelet cohesion. Platelets come together and stick together after they influx to the area to form the clot.
Describe the secretion phase in the functional response of platelets.
Release of platelet granule proteins. This protein secretion helps to start the procoagulant activity phase
Describe the procoagulant activity phase in the functional response of platelets.
Enhancement of thrombin (protein) generation
Give a cursory summary of the process of clot formation.
- Tissue damage
- Vascular Spasm
- Exposed collagen attracts platelets
- Platelet plug formation
- Blood coagulation: Damaged cells and platelets cause reaction that yields prothrombin activator. This activates the common pathway [Prothrombin → Thrombin; Fibrinogen → Fibrin]
- Blood cells trapped in fibrin threads → Clot formed!
Describe the difference between intrinsic and extrinsic pathways in the clotting response.
BOTH respond to injury
- Intrinsic: Responds to the Endothelial wall injury
- Extrinsic: Responds to the skin wound
Clotting Degradation:
____ (abbreviation: __) is a normally-secreted protease that along with ___ helps to break down plasminogen into ___. This conversion can also be done pharmacologically to break down clots, e.g. in the ___ to stop the effects of a ____.
Clotting Degradation: PLASMINIOGEN ACTIVATOR (abbreviation: tPA) is a normally-secreted protease that along with PA1 helps to break down plasminogen into PLAMSIN. This conversion can also be done pharmacologically to break down clots, e.g. in the BRAIN to stop the effects of a STROKE.
___ is an enzyme that breaks down the clot matrix.
PLASMIN
What happens if you have an excess of tPA?
tPA = Plasminogen Activator
Clots struggle to form, and you’d keep bleeding. An adverse effect of pharmacological tPA can cause increased bleeding, but the benefit of breaking up a dangerous clot outweighs the risk
Hemopheliacs lack clotting factor ___ in the clotting cascade.
Factor VII. Puts them at risk for bleeds
Prothrombin time (PT) is a measure of ___. Its reference value is __-___ seconds. Therapeutic Range: __-___x Normal. If this value is HIGH, you’re concerned about ___. This is done in [inpatient/outpatient] settings.
Prothrombin time (PT) is a measure of HOW LONG IT TAKES FOR BLOOD TO CLOT. Reference value is 12-15 SECONDS. Therapeutic Range: 1.5-2.5x Normal. If this value is HIGH, you're concerned about BLEEDING. This is done in INPATIENT settings, but is NOT comparable between institutions.
Partial Thromboplastin Time (PTT) is a monitor of ___. Its reference value is __-___ seconds. Therapeutic Range: __-___ seconds. If this value is HIGH, you’re concerned about ___. This is done in [inpatient/outpatient] settings.
Partial Thromboplastin Time (PTT) is a monitor of LOW MOLECULARWEIGHT HEPARIN (LMWH) - measures how quickly your blood clots. Its reference value is 30-40 seconds. Therapeutic Range: 50-80 seconds. If this value is HIGH, you’re concerned about BLEEDING. This is done in INPATIENT settings, but is NOT comparable between institutions.
International Normalized Ratio (INR) is used only in [outpatient/inpatient] settings. Its reference value is ___-___; therapeutic range: __-__. It takes [how long?] to test and [is/is not] standardized across institutions. A high INR means ___
International Normalized Ratio (INR) is used only in OUTPATIENT settings. Its reference value is 0.9-1.1; therapeutic range: 2-3. It takes A FEW DAYS to test [TESTED WEEKLY] and IS standardized across institutions. High INR = blood takes longer to clot (increased bleeding risk)
Which two coagulation measures give instant results? Used in ___ settings. [Comparable/not comparable] between hospitals. High values for these mean ___.
PT & PTT (Prothrombin Time & Partial Thromboplastin Time)
INPATIENT settings, can’t compare between hospitals
High values = at risk for bleeding
Of the coagulation measures, which measures the EXTRINSIC pathway? What chemical is measured?
PT (Prothrombin time). Measures Coumadin
Which coagulation measure measures the INTRINSIC pathway? What chemical is measured?
PTT (Partial thromboplastin time). Measures Heparin
Which coagulation measure measures the COMMON clotting pathway? What chemical is measured?
PTT (Partial thromboplastin time). Measures Heparin
The International Normalized Ratio (INR) measures what chemical? What other coagulation test also measures this chemical?
COUMADIN. Also measured by PT
__ is a straw-colored liquid that acts as a transportation system in blood. It accounts for __% of blood volume. ___% of this stuff is made up of water.
PLASMA is a straw-colored liquid that acts as a transportation system in blood. It accounts for 55% of blood volume. 90% of PLASMA is made up of water.
Other than water, what constitutes the other 10% of plasma? (Go for 6…)
Dissolved proteins Glucose Clotting factors, Electrolytes/mineral ions (Mg, Ca, K, Na) Hormones CO2
Of the dissolved proteins in plasma, ___ makes up 60%. It is involved with ___ pressure and acts as transport molecules. Other proteins include ___ (37%), ___ (4%), alpha 1-antitrypsin, and regulatory proteins (gene expression).
Of the dissolved proteins in plasma, ALBUMIN makes up 60%. It is involved with OSMOTIC pressure and acts as transport molecules. Other proteins include IMMUNO-GLOBULINS [immune sys] (37%), FIBRINOGEN (4%), alpha 1-antitrypsin, and regulatory proteins (gene expression).