Hemostasis

Question 1

is a complex process whose function is to limit blood loss from an injured vessel.

Answer 1

Hemostasis

Question 2

4 major physiologic events participate in the hemostatic process:

Answer 2

vascular constriction,
platelet plug formation,
fibrin formation,
and fibrinolysis

Question 3

is the initial response to vessel injury.

Answer 3

Vascular constriction

Question 4

is produced locally at the site if injury via the release of arachidonic acid from platelet membranes and is a potent constrictor of smooth muscle

Answer 4

Thromboxane A2 (TXA2)

Question 5

Platelets play an integral role in hemostasis by forming a

Answer 5

hemostatic plug

Question 6

injury to the intimal layer in the vascular wall exposes ______ to which platelets adhere.

This process requires von Willebrand factor (vWF), a protein in the subendothelium

Answer 6

subendothelial collagen

Question 7

vWF binds to ____ on the platelet membrane.

Answer 7

glycoprotein (GP) I/IX/V

Question 8

Following adhesion,platelets initiate a release reaction that recruits other platelets from the circulating blood to seal the disrupted vessel. Up to this point, this process is known as

Answer 8

primary hemostasis

Question 9

are the principal mediators in platelet aggregation

Answer 9

Adenosine diphosphate (ADP) and serotonin

Question 10

has potent vasoconstriction and platelet aggregation effects.

Answer 10

TXA2

Arachidonic acid released from the platelet membranes is converted by cyclooxygenase to prostaglandin G2 (PGG2) and then to prostaglandin H2 (PGH2), which, in turn, is converted to TXA2.

Question 11

Arachidonic acid may also be shuttled to adjacent endothelial cells and converted to _____ which is a vasodilator and acts to inhibit platelet aggregation.

Answer 11

prostacyclin (PGI2),

Question 12

Platelet cyclooxygenase is irreversibly inhibited by aspirin and reversibly blocked by nonsteroidal anti-inflammatory agents but is not affected by

Answer 12

cyclooxygenase-2 (COX-2) inhibitors.

Question 13

,another protein secreted by the α-granule, stabilizes fibrinogen binding to the activated platelet surface and strengthens the platelet-platelet interactions.

Answer 13

Thrombospondin

Question 14

The _______ begins with the activation of factor XII that subsequently activates factors XI, IX,and VIII.
In this pathway, each of the primary factors is “intrinsic”to the circulating plasma, whereby no surface is required to initiate the process.

Answer 14

intrinsic pathway

Question 15

In the extrinsic pathway, ______ is released or exposed on the surface of the endothelium, binding tocirculating factor VII, facilitating its activation to VIIa.

Answer 15

tissue factor (TF)

Question 16

Clot formation occurs after fibrin monomers are cross-linked topolymers with the assistance of

Answer 16

factor XIII

Question 17

An elevated _______ is associated with abnormal function of the intrinsic arm of the cascade (II, IX, X, XI, XII),

Answer 17

activated partial thromboplastin time (aPTT)

Question 18

is associated with the extrinsic arm (II, VII, X).

Answer 18

prothrombin time (PT)

Question 19

Vitamin K deficiency or warfarin use affects factors

Answer 19

Factors II, VII, IX, and X.

1972

Question 20

most common congenital bleeding disorder

Answer 20

vWD

von Willebrand’s Disease

Question 21

a rare genetic platelet disorder, inherited in an autosomal recessive pattern, in which the platelet glycoprotein IIb/IIIa (GP IIb/IIIa) complex is either lacking or present but dysfunctional

Answer 21

Thrombasthenia, or Glanzmann thrombasthenia

Question 22

is caused by a defect in the GP Ib/IX/V receptor for vWF, which is necessary for platelet adhesion to the subendothelium.

Answer 22

Bernard-Soulier syndrome

Question 23

The most common intrinsic platelet defect is

Answer 23

storage pool disease.