Blood Clotting

Question 1

Appearance of centrifuged blood

Answer 1

Plasma 55%, Buffy coat; white blood cells and platelets, red blood cells 45%,

Question 2

Blood components; red blood cells

Answer 2

Derived from stem cells in bone marrow, also called erythrocytes, 98.5% of all O2 travels via RBCs

Question 3

Oxyhemoglobin

Answer 3

Transport of O2 via RBCs

Question 4

How many RBCs enter the bloodstream every second? What percentage is replaced in a day?

Answer 4

3 million RBCs enter each second, 1% are replaced each day

Question 5

What can’t RBCs divide?

Answer 5

Lack of nuclei and ribosomes

Question 6

Blood components; white blood cells

Answer 6

Also called leukocytes, primary role is defence

Question 7

Blood components; platelets

Answer 7

Contain enzymes and other substances important for clotting, clump together and stick to damaged walls

Question 8

How many days do platelets circulate before being removed by the spleen?

Answer 8

9-12 days

Question 9

Blood types;red blood cells / antigens

Answer 9

Type A - A antigen, Type B - B antigen, Type AB - both A and B antigens, Type O - neither A or B antigen

Question 10

Blood types; plasma / antibodies

Answer 10

Type A - antiB antibody, Type B - antiA antibody, Type AB - neither antibody, Type O - both antiA and antiB antibodies

Question 11

Are you Rh+ or Rh- if you have the Rh protein on the surface of the red blood cell?

Answer 11

Rh+ (O+, A+, B+)

Question 12

If you have no Rh proteins on the surface of the red blood cell, are you Rh+ or Rh-?

Answer 12

Rh- (O-, A-, B-) approx 15% of population

Question 13

What three phases occur in rapid overlapping sequence during Hemostasis?

Answer 13

Vascular spasm, platelet plug formation, coagulation or blood clotting

Question 14

Vascular spasm

Answer 14

Allow time for platelet plug formation and blood clotting to occur, constriction of damaged vessel

Question 15

What is vascular spasm triggered by?

Answer 15

Direct injury to smooth muscle, chemicals released by endothelial calls and platelets, reflexes initiated by local pain receptors

Question 16

Platelet plug formation

Answer 16

When endothelial lining is damaged and has exposed collagen fibres, von Willebrand factor is synthesized by endothelial cells and is released

Question 17

Von willebrand factor

Answer 17

Helps platelets adhere to damaged blood vessels and also carries important clotting protein called factor VIII

Question 18

What happens once platelets attach to damaged vessels?

Answer 18

Serotonin - enhances vascular spasm, adenosine diphosphate - attract more platelets to the site, thromboxane A2- enhances spasm and attracts more platelets to the site.

Question 19

How quickly is the platelet plug formed? Is it limited?

Answer 19

60 seconds and limited to the immediate area

Question 20

What are the two pathways to prothrombin activator in coagulation?

Answer 20

Intrinsic pathway, extrinsic pathway

Question 21

Intrinsic pathway

Answer 21

Slower, all factors needed for clotting are present in the blood

Question 22

Extrinsic pathway

Answer 22

Faster, begins with damaged endothelial cells

Question 23

Process if coagulation

Answer 23

Factor X - prothrombinase - prothrombin/thrombin - fibrinogen/fibrin

Question 24

Clot retraction and repair

Answer 24

Within 30 - 60 minutes the clot is stabilized, platelets contain contractile proteins and contract similar to muscle cells, pulls surrounding fibrin strands, squeeze serum from the mass, compact the clot and draw damaged vessel edges together

Question 25

Firbrinolysis

Answer 25

Removes unneeded clots when healing is occurred

Question 26

Plasmin

Answer 26

Fibrin digesting enzyme, lies dormant in the clot until signaled to be activated

Question 27

What drugs affect the blood clotting mechanisms?

Answer 27

Anticoagulants, platelet inhibitors, thrombolytics

Question 28

What are anticoagulant drugs used for?

Answer 28

Deep vein thrombosis, pulmonary embolism, myocardial infarction, atrial fibrillation, stroke