Blood and Hemostasis

Question 1

What is serum?

Answer 1

plamsa without blood-clotting proteins

Question 2

What does plasma contain that serum does not?

Answer 2

fibrinogen

Question 3

What is the function of fibrinogen?

Answer 3

It causes blood clotting and is a target for thrombin

Question 4

What is the function of albumin?

Answer 4

to exert major osmotic pressure on blood vessel walls

Question 5

Where are fibrinogens and albumins made?

Answer 5

the liver

Question 6

What is an erythrocyte devoid of?

Answer 6

granules and organelles

Question 7

What are the two major cytoskeletal components of an erythrocyte?

Answer 7

actin and spectrin

Question 8

What does ankyrin do?

Answer 8

links the spectrin-actin network and the plasma membrane by binding to spectrin and a transmembrane protein.

Question 9

What kind of transporter is in an erythrocyte membrane?

Answer 9

an anion transporter; it allows HCO3 to cross the plasma membrane in exchange for Cl (allows release of CO2 in the lungs).

Question 10

What are neutrophils?

Answer 10

components of the blood that phagocytize amoeboids and destroy certain bacterial walls.

Question 11

What is a basophil?

Answer 11

component of the blood that releases histamine and leukotrienes, which increase vascular permeability and slow contraction of smooth muscles.

Question 12

What is a eosinophil?

Answer 12

component of the blood that works with basosinophils; it phagocytizes antibody-antigen complexes and parasites.

Question 13

What is a lymphocyte?

Answer 13

a large round cell that secretes T (cell-mediated immunity) and B (plasma cells) lymphocytes.

Question 14

What is a monocyte?

Answer 14

a component of the blood that differentiates into osteoclasts or macrophages once it reaches tissue.

Question 15

What are platelets?

Answer 15

a component of the blood derived from megakaryocytes that participate in aggregation, clot formation, and repair the endothelium with platet plugs.

Question 16

What substance is released by endothelial cells that decreases platelet aggregation?

Answer 16

prostacyclin

Question 17

What is the site of synthesis of most of the proteins of the clotting cascade?

Answer 17

the liver

Question 18

What is hemostasis, and where is it most effective?

Answer 18

The elimination of bleeding small vessels such as capillaires, arterioles and venules.

Question 19

What is the hemostatic sequence of events in small vessels?

Answer 19

constriction of smooth muscle, constriction of vessels, decreased blood flow, formation of platelet plug, blood clotting (coagulation).

Question 20

During an injury, what is exposed in the vessel?

Answer 20

collagen fibers; this is what platelets bind to.

Question 21

When platelets bind to collagen, what is released?

Answer 21

ADP and thromboxane A (stimulates platelet aggregation)

Question 22

What is von Willenbrand factor?

Answer 22

a plasma protein that adheres platelets to the walls of damaged blood vessels.

Question 23

What is prothrombin activated by?

Answer 23

Factor XII

Question 24

When is factor XII activated?

Answer 24

after contact with collaged in the damaged vessel wall.

Question 25

What is the active form of prothrombin, and what does it do?

Answer 25

thrombin it catalyzes the conversion of fibrinogen to fibrin.

Question 26

What is fibrin?

Answer 26

a meswork in which platelets, blood cells and plasma become entrapped to form the actual clot. It is activated via thrombin and factor XIII

Question 27

What protein reshapes a blood clot?

Answer 27

fibrin; it is split into polypeptides by thrombin and activated by factor XIII.

Question 28

What causes the dissolution of blood clots?

Answer 28

the activation of plasminogen to plasmin; it is also known as finbrinolysis.

Question 29

What activates plasminogen to plasmin?

Answer 29

t-PA; t-PA and plasmin dissolve the clot.

Question 30

What is the intrinsic pathway?

Answer 30

The pathway that contains all of the necessary factors in the blood, including calcium (important cofactor).

Question 31

What is the extrinsic pathway?

Answer 31

The pathway that involves the formation of tissue factor (thromboplastin or factor III).

Question 32

What factor does factor XII activate in the intrinsic pathway?

Answer 32

factor XI.

Question 33

Kallikrein is activated by which factor?

Answer 33

Factor XII; kallkrein activates bradykinin, which increases vascular permeability.

Question 34

Kallikrein is a positive feedback for which factor?

Answer 34

factor XII.

Question 35

What is the activation for factors IX and X?

Answer 35

11 + thrombin = 9; 9 + 8 (thrombin) + Ca = 10; then common pathway

Question 36

What is the activation for factors VII and X in the extrinsic pathway?

Answer 36

thromboplastin = 7; 7 + Ca = 10; then common pathway

Question 37

What mechanism is activated by various cytokines from damaged tissue cells?

Answer 37

leukocytes

Question 38

What are two phases of leukocyte extravasation?

Answer 38

selectin and integrin phase

Question 39

What occurs during the selectin phase?

Answer 39

Binding of ligands to P-selections on inflamed tissue causes the leukocyte to roll along endothelium.

Question 40

What occurs during integrin phase?

Answer 40

Integrin receptors are activated on the membrane and promote transendothelial migration of leukocytes.

Question 41

What is erythroblastis fetalis?

Answer 41

an antibody condition in which the mother and fetus of the second pregnancy have different antigens.