Unit 4 - Blood

Question 1

Erythropoiesis

Answer 1

Process of producing RBCs in bone marrow

Question 2

Erythropoietin (EPO)

Answer 2

A hormone secreted by kidney when low O2 in blood

Stimulates eruthropoiesis by red marrow

Question 3

List 4 roles of thrombin in blood coagulation.

Answer 3

1. converts fibrinogen to fibrin
2. activates factor Xlll to stabilize fibrin mesh
3. acts in positive-feedback fashion to facilitate its own formation
4. enhances platelet aggregation

Question 4

hemostasis

Answer 4

arrest of bleeding from a broken blood vessel (aka stopping of hemorrhage)

Question 5

3 steps of Hemostasis

Answer 5

1. vascular spasm
2. formation of platelet plug
3. blood coagulation

Question 6

vascular spasm

Answer 6

when vessel is injured, PARACRINE is released by the endothelial lining of the injured vessel.

Constriction slows blood flow.

Question 7

formation of platelet plug (3 stages)

Answer 7

1. Platelet adhesion
2. Platelet reaction
3. Platelet aggregation

Question 8

Formation of platelet plug: adhesion

Answer 8

injury exposes collagen, which causes platelets to stick

Question 9

Formation of platelet plug: reaction

Answer 9

platelets degranulate releasing:

1. serotonin: a vasoconstrictor
2. ADP: attracts & degranulates more platelets
3. thromboxane A2: promotes aggregation, degranulation, & a vasoconstrictor

Question 10

Formation of platelet plug: aggregation

Answer 10

aka White Thrombus

Question 11

What makes up hemoglobin (Hb)?

Answer 11

Globin = 4 polypeptide chains of amino acids (protein)

Each polypeptide chain has a HEME unit

Each hemoglobin molecule can carry 4 O2 molecules

Question 12

neutrophils

Answer 12

• Leukocyte / WBC
• granulocyte; nuclei w/2-5 lobes
• make up 60-70% of white blood cells
• phagocytic - form NETs
• first defenders

Question 13

lymphocytes

Answer 13

• WBC
• agranulocyte
• 25-33% of WBC
• large nucleus
• B & T type
• involved in diverse infections & immune responses

Question 14

monocytes

Answer 14

• agranulocyte
• 3-8% of WBC
• differentiate into macrophages
• phagocytize pathogens & debris
• “present” antigens to activate other immune cells

Question 15

eosinophils

Answer 15

• granulocyte w/lobed nuclei
• 1-4% of WBC
• respond to allergies & parasitic infections

Question 16

basophils

Answer 16

• granulocyte w/lots of grans that cover nuclei
• < 1% of WBC
• store heparin & histamine

Question 17

Factor I

Answer 17

Fibrinogen - soluble plasma protein that converts to Fibrin

Both intrinsic & extrinsic

Question 18

Factor II

Answer 18

Prothrombin: factor X converts Prothrombin to Thrombin

both intrinsic & extrinsic

Question 19

What is thrombin?

Answer 19

activates Factor XIII - which stabilizes fibrin meshwork

Question 20

Factor III

Answer 20

Thromboplastin
released by damaged tissue
Initiates Extrinsic pathway (only)

Question 21

Factor IV

Answer 21

Ca2+
mineral required in most steps
both intrinsic & extrinsic

Question 22

Factor V

Answer 22

both intrinsic & extrinsic

Question 23

Factor VII

Answer 23

extrinsic only

Question 24

Factor VIII

Answer 24

Anti-hemophilia factor
instrinsic only
deficiency causes Hemophilia A

Question 25

Factor IX

Answer 25

intrinsic only

Question 26

Factor X

Answer 26

both | when activated acts as prothrombin activator

Question 27

Factor XI

Answer 27

intrinsic only

Question 28

Factor XII

Answer 28

Hageman Factor initiates fibrinolysis (breakdown of clot) triggers instrinsic pathway

Question 29

Factor XIII

Answer 29

fibrin stabilizing factor inserts cross-links between fibrin threads both

Question 30

plasmin

Answer 30

a plasma protein made in liver & present in blood inactive form is PLASMINOGEN activated by Factor XII gets caught in clot; later breaks it down

Question 31

Stages of Coagulation

Answer 31

1. Formation of Prothrombin activator (thru Instrinsic or Extrinsic pathway) 2. Conversion of Prothrombin to Thrombin 3. Conversion of Fibrinogen to Fibrin

Question 32

Extrinsic pathway

Answer 32

3 steps | initiated by Factor III - Tissue Thromboplastin -> goes straight to Factor X

Question 33

Instrinsic pathway

Answer 33

7 steps initiated by Factor XII - Hageman Factor Steps -- XII, XI, IX, X

Question 34

common pathway

Answer 34

``` Factor X -> prothrombin -> thrombin -> fibrinogen -> fibrin Factor XIII (activated by thrombin) -> stabilizes fibrin ```

Question 35

fibrinolysis

Answer 35

removal of clot after healing | plasmin breaks down clot

Question 36

3 chemicals that prevent thrombosis

Answer 36

1. heparin 2. Tissue Plasminogen Activator (tPA) - from lungs 3. Antithrombin III - from liver; deactivates thrombin before it can act on fibrinogen

Question 37

role of vit K

Answer 37

involved in the synthesis of many clotting factors

Question 38

Warfarin (drug)

Answer 38

given to prevent clotting vit K antagonist interferes w/formation of clotting factors II, VII, IX, X