LAB EVAL OF PRIMARY HEMOSTASIS (LESSON 2 MIDTERM)

What diluting fluid is used in the indirect quantitative platelet counting method?

None

What clinical screening test evaluates platelet plug formation by determining the time required for bleeding to stop after a skin incision?

Bleeding time

What test was historically used as a screening procedure to assess platelet activity and vascular integrity?

Bleeding time

In the grading of the capillary resistance test, what qualitative result corresponds to 2+?

Many petechiae on the anterior part of the forearm

In the grading of the capillary resistance test, what qualitative result corresponds to 3+?

Multiple petechiae over the anterior and the back of the hand

What disorder is suggested when a patient presents with a normal platelet count but prolonged bleeding time?

Von Willebrand disease or

if inherited - Bernard Soulier Syndrome

What is the normal percentage range of blood volume reduction during clot retraction when using the wire loop method?

44-67%

What drug irreversibly inhibits cyclooxygenase in platelets and must be avoided prior to platelet aggregation testing?

Aspirin

What plasma protein mediates platelet adhesion to subendothelial collagen and serves as the carrier protein for coagulation factor VIII?

Von Willebrand factor

What substance produced in the cyclooxygenase pathway promotes platelet aggregation?

Thromboxane A₂

When EDTA-induced platelet clumping is suspected, which anticoagulant tube should be used for recollection?

Sodium citrate

What is the anticoagulant-to-blood ratio required in a citrate tube used for coagulation testing?

1:9

What platelet membrane glycoprotein is part of the receptor complex responsible for platelet aggregation?

Glycoprotein IIb and IIIa

What laboratory method allows evaluation of both platelet morphology and platelet number using a peripheral smear?

Indirect method

Which type of platelet granules contains von Willebrand factor and Platelet Factor IV?

Alpha granules

What laboratory test is used as a marker for platelet activation by measuring substances released from platelet alpha granules?

Platelet factor IV and Beta Thromboglobulin Assay

What is the most prevalent hereditary disorder of platelet adhesion?

Von Willebrand disease

What test uses an unlabeled immunologic assay to measure platelet activation markers?

Platelet factor IV and beta-thromboglobulin assay

or Radioimmunoassay (RIA)

What platelet estimation method uses a Wright-stained peripheral blood smear for platelet counting?

Fonio’s and Dameshek method