Hematology Physio

Question 1

What are the components of blood

Answer 1

• plasma (55%)
• formed elements (erythrocytes (45%), leukocytes, platelets (1%))

Question 2

What is the normal pH range of our blood

Answer 2

7.35-7.45

Question 3

What is the average blood volume of adult males and females

Answer 3

Male: 5-6L
Female: 4-5L

Question 4

Describe the functions of blood

Answer 4

• Distribution (O2, nutrients, waste, hormones)
• Regulation (temp, pH, fluid)
• Protection (blood loss, infection)

Question 5

What are the components of plasma

Answer 5

- 90% water
- proteins mostly produced by the liver (albumin, globulin, fibrinogen)
- clotting factors
- hormones
- respiratory gases & electrolytes
- nutrients

Question 6

What is the normal albumin-globulin ration

Answer 6

4:2

Question 7

Does serum contain clotting factors?

Answer 7

No, clotting factors are found only in plasma

Question 8

What cell gives rise to all formed elements of our blood?

Answer 8

Multipotential hematopoietic stem cell (hemocytoblast)

Question 9

What are the two types of cells that differentiate from hemocytoblasts

Answer 9

common myeloid progenitor

common lymphoid progenitor

(these branch farther into many cells, leukemias will affect one line or the other)

Question 10

Define erythrocytes

Answer 10

• biconcave discs
• anucleate
• no organelles (anaerobic ATP production)
• contains spectrin

Question 11

What is the purpose of spectrin in erythrocyte plasma membranes

Answer 11

provides flexibility to change shape as needed

(deficiency leads to a type of anemia)

Question 12

Describe the structure of hemoglobin

Answer 12

• protein globin: 2 alpha & 2 beta chains (adults, 2 gamma in fetal)
• heme pigment bonded to globin
• iron atom in each heme (can bind 4 O2)

Question 13

What is a reticulocyte

Answer 13

a mature form of a red blood cell that is not yet an erythrocyte

(formed during erythropoiesis after nucleus is ejected)

Question 14

Where does erythropoiesis occur

Answer 14

red bone marrow

Question 15

What is a scenario in which reticulocyte count would be low

Answer 15

aplastic anemia

Question 16

What regulates erythropoiesis

Answer 16

Hormones
- erythropoietin
- testosterone

Nutrients
- amino acids, lipids, carbs
- iron
- vit B12

Question 17

What is iron stored in the cells as and what is it transferred by

Answer 17

Storage: ferritin & hemosiderin

Transport: transferrin

Question 18

What is the lifespan of a RBC

Answer 18

100-120 days

(then destroyed by macrophages in the spleen)

(Hgb A1C measures this)

Question 19

What happens after a RBC is broken down

Answer 19

• iron salvaged for reuse
• heme degraded to yellow pigment unconjugated bilirubin, which gets conjugated in the liver, excreted as stercobilin & urobilinogen
• globin metabolized into amino acids

Question 20

Define anemia

Answer 20

• blood has abnormally low O2 carrying capacity
• sign, not disease
• fatigue, pallor, SOB, chills

Question 21

What kinds of anemia are caused by insufficient erythrocytes

Answer 21

• hemorrhagic
• hemolytic (RBCs destroyed)
• aplastic (Bone marrow destroyed)

Question 22

What kinds of anemia are caused by low Hgb

Answer 22

• iron deficiency (secondary to hemorrhage, impaired iron absorption
• pernicious (Vit B12 deficiency, lack of intrinsic factor for absorption)

Question 23

What kinds of anemia are caused by abnormal Hgb

Answer 23

• thalassemia (absent/faulty globin, think delicate RBC)
• sickle cell (gene code, low in oxygen)

Question 24

When does sickling happen in sickle cell anemia

Answer 24

When oxygen dissociates from the heme (especially during high O2 demand like exercise)

Question 25

Define polycythemia

Answer 25

excess of RBCs that increase blood viscosity - bone marrow cancer, O2 loss, blood doping

Question 26

What process allows WBC to leave capillaries

Answer 26

diapedesis

Question 27

What makes up granulocytes & agranulocytes

Answer 27

**Granulocytes** - neutrophils (50-70%) - eosinophils (2-4% - basophils (1%) **Agranulocytes** - lymphocytes (25-45%) - monocytes (3-8%)

Question 28

Which WBCs will stain with Wright's stain

Answer 28

granulocytes (neutrophils, eosinophils, basophils) - larger, shorter lived - lobed nuclei - phagocytic

Question 29

Which WBC has granules that contain hydrolytic enzymes or defensins

Answer 29

Neutrophils (bacteria slayers)

Question 30

Which WBC digests parasitic worms & modulates immune response

Answer 30

eosinophils

Question 31

Which WBC contains histamine & functions similarly to mast cells

Answer 31

basophils

Question 32

Describe the 2 types of lymphocytes

Answer 32

- T cells: act against virus-infected cells & tumor cells - B cells: give rise to plasma cells that produce antibodies

Question 33

What is the largest WBC and what does it do

Answer 33

monocytes - differentiates into macrophages - activates lymphocytes for immune response

Question 34

What chemical messengers from bone marrow & mature WBCs stimulate leukopoiesis

Answer 34

interleukins & colony-stimulating factors

Question 35

Describe platelets

Answer 35

- anucleate cell fragments - formation regulated by thrombopoietin (hormone from liver & kidneys)

Question 36

What are in the granules of platelets & why are these important

Answer 36

- Ca, enzymes, ADP, phospholipids, platelet derived growth factor, serotonin - important in hemostasis

Question 37

What does the platelet membrane consist of

Answer 37

- lipid bilayer - glycoprotein receptors (important in hemostasis)

Question 38

What are the functions of platelets

Answer 38

- form temporary plugs that seal breaks in blood vessels - circulating when inactive and made mobile by nitric **oxide & prostacyclin from endothelial vessel lining**

Question 39

Describe the phases of hemostasis

Answer 39

- primary (vascular spasm & platelet plug) - secondary (coagulation) - stoppage of hemostasis (proteins) - fibrinolysis (clot dissolves)

Question 40

Describe the steps of platelet plug formation (step 2 of hemostasis)

Answer 40

- adhesion via vWB factor - aggregation via ADP - secretion of granular contents

Question 41

Describe coagulation (step 3 of hemostasis)

Answer 41

- reactions in which blood is transformed from liquid to gel - reinforces platelet plug with fibrin threads - requires coag/clotting factors, Ca, phospholipids

Question 42

Describe the 3 phases of coagulation

Answer 42

- prothrombin activator formed - prothrombin converted to thrombin - thrombin catalyzes fibrinogen to form fibrin mesh

Question 43

Which clotting factors require vitamin K

Answer 43

Factors II, VII, IX, and X

Question 44

What is the major difference between the intrinsic pathway and extrinsic pathway of clotting

Answer 44

Intrinsic: direct to blood vessel injury Extrinsic: tissue cell trauma prior to blood vessel response

Question 45

What forms all clotting factors

Answer 45

the liver (all circulate in blood in an inactive form)

Question 46

What is the main end product of phase 1 of coagulation

Answer 46

formation of prothrombin activator (activates prothrombin to thrombin in phase 2)

Question 47

What is the main end product of phase 3 of coagulation

Answer 47

fibrin mesh

Question 48

Describe clot retraction

Answer 48

- actin & myosin in platelets contract within 30-60 mins which squeezes serum from the clot

Question 49

Describe clot repair

Answer 49

- **PDGF** stimulates division of smooth muscle cells & fibroblasts to rebuild vessel - **VEGF** stimulates endothelial cells to restore lining

Question 50

Which proteins inactivate activated clotting factors

Answer 50

- antithrombin III - protein C - heparin

Question 51

What things prevent platelet adhesion

Answer 51

- nitric oxide, prostacyclin (from endothelial lining) - vit E, quinine (anticoags)

Question 52

Describe fibrinolysis

Answer 52

- begins within 2 days - plasminogen converted to plasmin by tPA, factor XII, thrombin

Question 53

Describe disseminated intravascular coagulation (DIC)

Answer 53

- widespread clotting blocking intact blood vessels - can cause severe bleeding - common in pregnancy, septicemia, incompatible transfusion - prevention: ASA, heparin, warfarin

Question 54

Describe thrombocytopenia

Answer 54

- deficiency of platelets - petechiae d/t spontaneous widespread hemorrhage - tx with transfusion of concentrated platelets

Question 55

Describe the types of hemophilia

Answer 55

- A: most common, deficiency of factor VIII - B: deficiency of factor IX - mild, deficiency of factor XI - prolonged bleeding (into joints)

Question 56

Which blood groups can cause vigorous transfusion reactions

Answer 56

ABO & Rh

Question 57

Which blood group is a universal recipient

Answer 57

AB

Question 58

Which blood group is a universal donor

Answer 58

O

Question 59

Which blood group can receive blood from B or O

Answer 59

B (has anti-A antibody)

Question 60

Which blood group can receive blood from A or O

Answer 60

A (has anti-B antibody)

Question 61

Which blood group can receive blood from only group O

Answer 61

O (has anti-A and anti-B antibodies)

Question 62

Which blood group can receive blood from A, B, AB, or O

Answer 62

AB (no antibodies)

Question 63

When do Rh antibodies form

Answer 63

- if an Rh negative person receives Rh+ blood - NOT spontaneous

Question 64

Describe hemolytic disease of the newborn (erythroblastosis fetalis)

Answer 64

anti-Rh antibodies cross placenta and destroy RBCs of an Rh+ baby after Rh- mom becomes sensitized to Rh+ exposure & produces anti-Rh antibodies

Question 65

What happens in a transfusion reaction

Answer 65

- occurs in mismatched infusions - donors cells are attacked by recipients agglutinins, clog small vessels, rupture & release Hgb - diminished O2 capacity, renal failure