Deck 28: Primary Hemostasis

Question 1

After a blood vessel injury, hemostasis is initiated by which of the following?

A)Endothelial communication
B)Platelet function inhibition
C)Vasoconstriction
D)Vasodilation

Answer 1

Vasoconstriction

Question 2

All of the following are associated with shape change in platelet activation except:

A)Actin and myosin convert to a parallel arrangement from a random arrangement.
B)The platelet converts to a spiked sphere appearance from a flattened disc appearance.
C)Tubulin forms a circumferential band around the organelle zone and contracts.
D)Organelles sequester granule contents.

Answer 2

Organelles sequester granule contents.

Question 3

The structures of different blood vessels are similar, but the functions are distinct.Which blood vessels serve as the major site of regulation of vascular permeability?

A)Arterioles
B)Venules
C)Capillaries
D)Lumen

Answer 3

Venules

Question 4

Which of the following substances is found in all three layers of the blood vessel?

A)Fibroblasts
B)Collagen
C)Laminins
D)Glycoproteins

Question 5

Nuclear replication without cytoplasmic division is defined as:

A)Asynchrony.
B)Dysmyelopoiesis.
C)Hematopoiesis.
D)Endomitosis.

Question 6

What is the first step in coagulation that occurs after vascular trauma?

A)Vasoconstriction at the site of injury
B)Platelet adhesion to collagen
C)Platelet activation and shape change
D)Platelet aggregation to more platelets

Question 7

Which of the following layers of blood vessels is responsible for secretion of procoagulant proteins to maintain tissue repair?

A)Tunica adventitia
B)Tunica intima
C)Tunica media
D)All of the above

Question 8

Sequential activation of serine proteases that induce formation of insoluble blood proteins occurs in which phase of coagulation?

A)Formation of primary platelet plug
B)Formation of secondary hemostatic plug
C)Fibrinolysis of existing hemostatic plugs
D)Inhibition of primary and secondary hemostatic plug formation

Question 9

Formation of a blood clot on the interior surface of an intact (unsevered) vessel is referred to as:

A)Blood coagulation.
B)Hemostasis.
C)Thrombosis.
D)Fibrinolysis.

Question 10

Transient cessation of blood loss is achieved through which of the following?

A)Formation of secondary hemostatic plug
B)Fibrinolysis of established thrombus
C)Formation of primary platelet plug
D)Inhibition of thrombus formation

Question 11

Which of the following represents a normal platelet number and morphology?

A)A platelet that is 10 µM in size, with a blood concentration of 200 x 109/L
B)A platelet that is 80 µM in size, with a blood concentration of 8 x 109/L
C)A platelet that is 2.5 µM in size, with a blood concentration of 250 x 109/L
D)A platelet that is 5 µM in size, with a blood concentration of 600 x 109/L

Question 12

The strength of a selected agonist is defined by which of the following?

A)Location from where they are derived
B)Their ability to induce the full range of platelet functions
C)Their ability to interact with thromboxane A2
D)The speed by which the platelets become activated

Question 13

All of the following are considered major players in coagulation except:

A)Platelets.
B)Procoagulant inhibitors.
C)Heparan.
D)Serine proteases.

Question 14

Secondary hemostasis involves which of the following events to further hemostasis?

A)Generation of fibrin
B)Blood remains a liquid
C)Fibrinolysis occurs
D)Inhibition of platelet release reaction

Question 15

What is the typical concentration of platelets in the blood?

A)200-600 x 108/L
B)150-440 x 108/L
C)150-440 x 109/L
D)250-500 x 109/L

Question 16

The circulatory system's ability to maintain the blood as a fluid within the blood vessels and to prevent excessive blood loss upon injury is defined as which of the following?

A)Clot retraction
B)Hemostasis
C)Coagulation
D)Thrombosis

Question 17

Which of the following acts as a transport portal for granules to move from the organelle zone to the membrane zone?

A)Open canalicular system
B)Dense tubular system
C)Membrane glycoproteins
D)Endoplasmic reticulum

Question 18

Platelet adhesion to collagen and the initiation of platelet aggregation are part of:

A)Primary hemostasis.
B)Secondary hemostasis.
C)Blood coagulation inhibition.
D)Fibrinolysis.

Question 19

Platelets are derived from which of the following?

A)Monoblasts
B)Pronormoblasts
C)Lymphoblasts
D)Megakaryocytes

Question 20

Which substance, stored in the dense bodies, is responsible for platelet activation, and is also involved in activation of the coagulation cascade?

A)PDGF
B)ADP
C)Calcium
D)Thrombospondin

Question 21

Which of the following is responsible for the platelet surface negative charge, and is found on the surface membrane of the interior channels?

A)Dense tubular system
B)Open canalicular system
C)Submembranous cytoskeleton
D)Glycocalyx

Question 22

Which of the following is a role of the platelets in secondary hemostasis?

A)To provide factors needed for serine protease activation
B)To initiate cross-linking of the fibrin monomers
C)To activate thrombin
D)To initiate contact activation

Question 23

Correlate blood vessel histology to vessel type and function in hemostasis.

Question 24

During what stage of megakaryocyte development are the platelets released into the circulation?

A)Between stages III and IV
B)At the end of stage II
C)During the cycling phase
D)At the point of proplatelet formation.

Question 25

Describe megakaryocyte development, and the role of endomitosis and thrombopoietin in this process.

Question 26

Which of the following best describes the role of "platelet factor 4"?

A)Stimulates platelet aggregation
B)Contributes to fibrin formation
C)Neutralizes heparin
D)Mitogenic factor

Question 27

How does the vascular system contribute to hemostasis?

Question 28

Which function of the endothelial cell keeps cells and macromolecules in vessels, and allows nutrient and gas exchange?

A)Processing of blood-borne antigens
B)Production of tissue factor
C)Production of nitric oxide
D)Selective blood/tissue barrier

Question 29

Explain the biochemistry involved in platelet function.

Question 30

On average, how long does a platelet live in the peripheral circulation?

A)6 hours
B)120 days
C)5 days
D)10 days

Question 31

Which of the following substances functions to stabilize platelet aggregates in the platelet plug?

A)PDGF
B)Thrombospondin
C)Factor V receptor
D)PF4

Question 32

Which platelet ultrastructural zone has the functions of secretion, storage, and lipid metabolism?

A)Peripheral zone
B)Structural zone
C)Organelle zone
D)Membrane systems

Question 33

Which of the following substances endogenous to the dense bodies is responsible for continuous platelet activation of surrounding platelets?

A)Platelet factor 4
B)Collagen
C)ADP
D)Epinephrine

Question 34

The formation of thromboxane A2 in the activated platelet:

A)Is needed for platelets to adhere to collagen.
B)Assists in the secretion of granule contents.
C)Requires the enzyme cyclo-oxygenase.
D)Requires von Willebrand factor.