Clinical Pathology - Exam 1

Front 1

Where is bone marrow primarily found?

Back 1

long and flat bones

Front 2

Name products of marrow hematopoiesis?

Back 2

-RBCs - oxygen delivery to tissues
-WBCs - host defense
- Platlets - hemostasis

Front 3

How many days from stem (rhubroblast) cell to reticulocyte release?

Back 3

5

Front 4

What happens with erythropoiesis?

Back 4

start with large blast cells; cells become smaller with maturation and divisions; increased hemoglobin

Front 5

What starts with an early rubricyte?

Back 5

hemoglobin synthesis starts

Front 6

What happens with a late rubricyte?

Back 6

- critical hemoglobin concentration is reached
- shuts off cell division
-continues to mature

Front 7

What happens with a metarubricyte?

Back 7

- nucleus is small and pyknotic
- ready to extrude nucleus

Front 8

What happens with a reticulocyte (polychromatophilic RBC)?

Back 8

-nucleus is extruded
-contains residual RNA and organelles
-released into marrow sinus (except horse)
-the residual organs give it a bluish color
-increases numbers indicate a response

Front 9

Explain the process of reticulocyte release.

Back 9

-micrates through endothelial cells into venous sinuses
-matures 24 hours in blood
-spleen pits the organells

Front 10

What stain is used for reticulocyte ID?

Back 10

New methylene blue stain

Front 11

Explain the characteristics of a mature RBC.

Back 11

-no RNA
-gains full hemoglobin
-loses blue grey color

Front 12

What is the life span of a mature RBC?

Back 12

70-160 days (about 100)

Front 13

What characterizes anemia?

Back 13

-decrease in:
(1) #RBC/microL;
(2) hemoglobin/dl;
(3) %PCV (Hct)

-RBC loss or destruction > production

Front 14

What is the body's response to anemia?

Back 14

-anemia decreases oxygen carrying capacity
-renal hypoxia causes EPO release from cortex
-EPO stimulates: erythrocyte progenitors, hemoglobin production and early marrow release
-takes 2-3 days

Front 15

What does EPO stimulate?

Back 15

erythrocyte progenitors, hemoglobin production and early marrow release

Front 16

What does anemia describe?

Back 16

a data abnormality, NOT a diagnosis or a disease

Front 17

What does the RBC indice mean: MCV

Back 17

mean corpuscular volume - used in classification of anemia

-average volume of red cells

Front 18

What does the RBC indice mean: MCH

Back 18

mean corpuscular hemoglobin - used in classification of anemia

-mean amount of hemoglobin per cell

Front 19

What does the RBC indice mean: MCHC

Back 19

mean corpuscular hemoglobin concentration - used in classification of anemia
-mean concentration of hemoglobin per cell

Front 20

How is MCV measured?

Back 20

by instrument
-calculated by HCT X 10 / RBC

Front 21

Where are the values MCV, MCH, and MCHC found?

Back 21

on CBC data sheets
-calculated using RBC, HGB, and HCT

Front 22

If a patient is anemic and MCV is < the reference interval what is this called?

Back 22

Microcytic anemia - cells average smaller than normal

Front 23

If a patient is anemic and MCV is within the reference interval what is this called?

Back 23

Normocytic anemia - cells have average normal volume

Front 24

If a patient is anemic and MCV is > the reference interval what is this called?

Back 24

Macrocytic anemia - increased number of reticulocytes

Front 25

Give an example of a cause of microcytic anemia. Explain.

Back 25

Iron deficiency

-hemoglobin synthesis needs iron
-critical (HGB) reached late rubricyte (normal)
-results in extra (5th rubricyte division
-smaller cells in circulation

Front 26

Give an example of a macrocytic anemia. Explain.

Back 26

Regenerative anemia - reticulocytes present

Front 27

Which is more accurate, MCH or MCHC?

Back 27

MCHC --> mean concentration of hemoglobin/cell

Front 28

What is the difference between MCH and MCHC?

Back 28

MCH - mean AMOUNT of hemoglobin/cell

MCHC - mean concentration of hemoglobin/cell

Front 29

What are the values of MCH, MCV, and MCHC in the case of reticulocytosis?

Back 29

-MCH is normal
-MCV is increased
-MCHC is decreased

Front 30

What is the term if MCH or MCHC is < the reference range?

Back 30

hypochromic - iron def. or less HGB/cell

Front 31

What is the term if MCH or MCHC is in the reference range?

Back 31

Normochromic

Front 32

What is the term is MCH or MCHC is > the reference range?

Back 32

hyperchromic - FAKE

Front 33

What does a hyperchromic result usually mean?

Back 33

FAKE - indicates RBC lysis (introvascular hemolysis or poor sample handling)
-can mean presence of Heinz bodies

Front 34

How are anemias classified?

Back 34

(1) Size (MCV) --> macrocytic, normocytic or microcytic

(2) Classify as to hemoglobin (MCH, MCHC) --> hyperchromic, normochromic, hypogromic

(3) reticulocyte count -->regenerative or non-regenerative

Front 35

How many reticulocytes are normally in a canine and what type?

Back 35

1% - aggregate - all are counted

Front 36

How many reticulocytes are normally in a feline and what type?

Back 36

0.4%
-2 types:
(1) aggregate (counted)
(2) punctate (not counted)

Front 37

Where are reticulocytes found in the horse?

Back 37

they are not - absent in health and in anemias because complete bone marroe maturation of RBCs in bone marrow

Front 38

What are 3 major causes of anemia?

Back 38

(1) blood loss - acute/chronic; internal/external
(2) hemolysis - inra or extra vascular
(3) lack of production

Front 39

Non-regenerative anemia is often a result of what?

Back 39

production failure - BM

Front 40

What are the most likely causes of regenerative anemia?

Back 40

Lysis>Loss
-can tell by plasma proteins

Front 41

What happens when epinephrine is released?

Back 41

-spleen contracts
-releases HCT (80%) and platelets (1/3 of ciruclating platelets stored in spleen)

Front 42

What happens with fluid therapy hours to days later?

Back 42

-dilutes cells and proteins --> anemia and hypoproteinemia

Front 43

How long does it take reticulocytosis to develop?

Back 43

-2-3 days
-max of 7-10 days because it takes 5 days for stem cells to develop

Front 44

How long does it take for reticulocytosis to resolve?

Back 44

1-2 weeks

Front 45

What are signs of regeneration?

Back 45

(1) macrocytosis (increased MCV)
(2) hypochromia (decreased MCHC)
(3) reticulocytosis
($) hypercellular bone marrow

Front 46

How is metarubricytosis classified?

Back 46

appropriate (nRBCs with reticulocytosis)
or
inappropriate (nRBCs without reticulocytosis)

Front 47

What is the most common cause of iron def?

Back 47

chronic hemorrhage

Front 48

How many divisions occur when there is an iron deficiency?

Back 48

5 b/c longer to reach critical HB

Front 49

What are typical findings of an animal with chronic hemorrhage?

Back 49

-anemia (microcytic, hypochromic, less regenerative)
-panhypoproteinemia
-thrombocytosis

Front 50

If anemia is regenerative, what two types could it be?

Back 50

loss or lysis

Front 51

Blood loss can be ..

Back 51

acute/chronic
or internal/external

Front 52

Hemolysis can be...

Back 52

intravascular or extravascular

Front 53

Non-regenerative anemia can be caused by what?

Back 53

lack of production

Front 54

What are 2 rule outs for microcytosis?

Back 54

(1) iron deficiency
(2) portosystemic shunts
(asian breed dogs)

Front 55

What are reasons for macrocytosis?

Back 55

regneration; agglutination

Front 56

What is a reason for hypochromasia?

Back 56

low iron
reticulocytosis (because less hemoglobin per cell)

Front 57

What is a reason for hyperchromasia?

Back 57

artifact; hemolysis
Heinz Body anemia
Hemolytic Anemia

Front 58

Can intra and extravascular hemolysis occur at the same time?

Back 58

yes

Front 59

What is a normal % of RBCs that are destroyed and made at the same time?

Back 59

1%

Front 60

Where are RBCs phagocytosed by macrophage?

Back 60

-in spleen or liver - normal is 1%

Front 61

What phagocytoses RBCs and what happens after this is done?

Back 61

-macrophages
- and then lysed and digested in the phagosome

Front 62

After RBC are lysed, what happens to hemoglobin?

Back 62

-it is digested to (1) globin and (2) heme
(1) globin--> amino acids
(2) heme --> iron (recycled) and bilirubin (another tour)

Front 63

Once bilirubin goes into the blood, it is bound to what?

Back 63

albumin as unconjugated bilirubin

Front 64

Once bilirubin goes into the blood, what happens?

Back 64

bound to albumin (unconjugated) --> goes to hepatocyte (glucuronide conjugation) --> conjugated bilirubin is excreted into the bile --> bile does to SI to help with digestion

Front 65

What is happening if you see bilirubin increased?

Back 65

hemolysis

Front 66

Why does extravascular hemolysis occur?

Back 66

-accelerated RBC phagocytosis by splenic macrophages (more common) or liver (less common); the macrophages line the sinusoids
-macrophages detect an abnormality on RBC membrane surface

Front 67

Give an example of what type of RBCs may be phagocytosed by macrophages thus causing extravascular hemolysis.

Back 67

antibody on RBC, RBC parasite or Heinz Body

Front 68

When a RBC is phagocytosed partially, what re-forms?

Back 68

a spherocyte

Front 69

RBC phagocytosis results in what?

Back 69

RBC destruction (hemolysis_ - regenerative

Front 70

Spherocytes (partial phagocytosis) represents what?

Back 70

RBC targeting
-spherocytes are more likely to be phagocytosed

Front 71

What are possible lab findings of hemolysis anemia?

Back 71

-hyperbilirubinemia
-moderate to marked reticulocytosis (iron is being recycled)
-positive direct antiglobulin test - detects antibody
-autoagglutination
-abnormal RBCs on smear - hemic parasites, heinz bodies

Front 72

What does the following test show/detect?
(1) Positive Direct Antiglobuilin Tests (Coomb's)
(2) autoagglutination

Back 72

(1) detects anti-RBC antibodies and complement bound to RBC surface --> IMHA (primary or secondary)and indicated hemolytic anemia

Front 73

What does the following test show/detect?
(2) autoagglutination

Back 73

(2) Anti-RBC IgM or IgG (red cells cluster as grapes); infers hemolytic anemia (also will get increased MCV)

Front 74

In what species is rouleaux normal?

Back 74

-equine
-this must be disdinguished from autoagglutination (red cells stack like coins)

Front 75

Why is Rouleaux abnormal in most species?

Back 75

-most species have a negatively charged surface membrane that repels other neighbors

Front 76

What is a possible cause of Rouleaux and why?

Back 76

-inflammation increases proteins in blood and coats surface nonspecifically (fibrinogen)
-this masks the negative charges and therefor no longer repels each other

Front 77

How do you tell the difference between Autoagglutination and rouleaux?

Back 77

-dilute with saline 1:10
-wet mount, rouleaux disperses and autoagglutination remains

Front 78

What is it called when bilirubin spills into the urine?

Back 78

bilirubinuria

Front 79

What does hyperbilirubinemia mean?

Back 79

hemolysis - pathologic

Front 80

What are signs of regeneration?

Back 80

-macrocytosis - increased MCV
-hypochromia - decreased MCHC
-reticulocytosis
-increased target cells
-hypercellular bone marrow - erthroid hyperplasia

Front 81

What are target cells?

Back 81

-bull's eye pattern
-occur in regenerative anemia because they have skipped a division and are therefore bigger cells with an increased surface volume

Front 82

What type of reticulocyte count is preferred?

Back 82

absolute-->
% x RBC (millions) = reticulocyte #

Front 83

What is normoblastemia?

Back 83

nRBCs in ciruclation (metarubricyes) - 1/100 WBC

Front 84

What is the difference between appropriate and inappropriate metarubricytosis?

Back 84

-appropriate metarubricytosis -- nRBC with lots of polychromasia (reticulocytes)

-inappropriate metarubricytosis - increased nRBC without regeneration (or even without anemia)

Front 85

What are some causes of metarubricytosis?

Back 85

-severe hypoxia
-heavy metal toxicosis
-bone fractures
infiltrative bone marrow disease (leukemia)
-extramedullary hematopoiesis - from spleen
-heat stroke
-sepsis

Front 86

What occurs with slow onset of anemia due to chronic blood loss?

Back 86

adaptation to lowered oxygen
-increased 2,3 DPG (not cow or cat)
-increased erythropoiesis

Front 87

What does chronic blood loss cause?

Back 87

-depleted iron stores (external or internal) - GI, urinary are most common
-most common cause of iron def (esp young animals because they already have a low iron diet)

Front 88

What type of anemia is caused by iron def?

Back 88

-microcytosis and hypochromasia
-regenerative initially and then non-regenerative eventually
-increased RBC fragility - less deformable

Front 89

Where is iron stored?

Back 89

BM, liver, spleen

Front 90

What are (4) typical findings with chronic blood loss?

Back 90

(1) anemia --> microcytic, hypochromic, regeneration, then less so
(2) panhypoproteinemia - all proteins lost with RBCs
(3) thrombocytosis - reactive cytokine-mediated
(4) characteristic RBC poikilocytosis -- different shapes of RBCs

Front 91

Hyperbilirubinemia means what?

Back 91

hemolysis - pathologic

Front 92

Bilirubin that spills into the urine, bilirubinuria is normal (in small amounts) for what species?

Back 92

dogs

Front 93

What are causes of hemolysis?

Back 93

extra-vascular
-intra-vascular
-overlap of the two

Front 94

What does oxidative damage cause?

Back 94

-intravascular and extravascular hemolysis
-denatures hemoglobin
-denatures hemoglobin and hemoglobin precipitates and aggregates forming heinz bodies
-heinz bodies and eccentrocytes

Front 95

What animal is more susceptible to heinz bodies?
why?

Back 95

-cats are more susceptible because not removed as effectively by the spleen; hemoglobin conformation is different
-5% heinz bodies is normal in cats

Front 96

What are heinz bodies?

Back 96

-HGB precipitates under cell membrane after oxidative damage that is irreversible
-this causes a membrane abnormality
-splenic macrophages "pit" the Heinz bodies
-OR in more severe cases, Heinz bodies weaken the RBC membrane and the cells lyse in circulation
-this causes RBC ghosts due to increased membrane fragility

Front 97

What are some causes of oxidative damage that eventually cause heinz bodies?

Back 97

onions, garlic, acetaminophin, zinc, red maple; cats are more susceptible

Front 98

What happens with intravascular hemolysis?

Back 98

-red cells are lysed in circulation and spill out the hemoglobin
-cause hemoglobinemia --> instead of clear, you see a red tinged plasma because there is hemoglobin free in circulation

Front 99

With intravascular hemolysis, what it the relationship of HGB X 3 to PCV?

Back 99

HGB X 3 > PCV
-they normally are about equal to each other
-MCHC is also increased

Front 100

Why is it important with intravascular hemolytic anemia to tie up the free hemoglobin?

Back 100

(1) need to conserve the Fe (HGB --> heme --> Fe and bilirubin
(2) hemoglobin can be toxic to renal tubules (the Fe in it) - more in horses and people

Front 101

What does Fe in the renal tubules cause?

Back 101

-causes redox reactions

Front 102

What recovers and binds free hemoglobin as a result of intravascular hemolysis

Back 102

-the haptoglobin recovery system (the liver produces the haptoglobin)
-haptoglobin binds free hemoglobin
-the hemoglobin-haptoglobin complex is huge and it is taken up by the hepatocyte

Front 103

Describe the signs of intravascular hemolysis.

Back 103

-acute
-may present BEFORE regeneration
-hemoglobinemia
-+/- hemoglobinuria if severe
-hyperbilirubinemia
-bilirubinuria

Front 104

Describe extravascular hemolysis.

Back 104

-chronic
regenerative response
-normal or increased plasma proteins
-+/-hyperbilirubinemia if acute or severe

Front 105

What do you call increased PCV?

Back 105

Erthrocytosis or polycythemia

Front 106

What are some examples of relative polycythemia?

Back 106

-hemoconcentration (dehydration, fluid shifts
-redistribution (excitement)

Front 107

What are some examples of absolute polycythemia?

Back 107

Primary - polycythemia vera (neoplasia)
- secondary - increased EPO

Front 108

What is the number one WBC is a cow and rabbit?

Back 108

lymphocyte

Front 109

What is used to count leukocytes?

Back 109

electronic particle counter

Front 110

What is used for a differential white cell count?

Back 110

absolute count = Total WBC x %

Front 111

What does a left shift mean?

Back 111

increased numbers of band neutrophils

Front 112

What is the difference of where RBCs and WBCs work?

Back 112

RBCs - inside vessels (oxygen transport)
WBCs - at tissue level

Front 113

What is the function of leukocytes?

Back 113

-fight pathogens --> infectious agents (bacterial, virus, rickettsial)
-neutrophils are the first line of defense

Front 114

The total number of blood neutrophils consists of what?

Back 114

circulating neutrophil pool and marginal neutrophil pool

Front 115

Name three types of neutrophilia?

Back 115

(1) excitement/physiological/epinephrine
(2) stress/corticosteroids
(3) inflammation

Front 116

What other changes occur with neutrophilia caused by excitement/physiological?

Back 116

-mature neutrophilia
-lymphocytosis
-erythrocytosis
-thrombocytosis

Front 117

Why does erythrocytosis and thrombocytosis occur with neutrophilia caused by excitement?

Back 117

-splenic contraction - increased hematocrit and oxygen carrying capacity (epinephrine response)
-platelets

Front 118

How long does epinephrine neutrophilia last and what type of neutrophilia is it?

Back 118

-transient - 20 minutes
-increased heart rate, blood flow

Front 119

Why does neutrophilia truly occur with excitement?

Back 119

-normally just circulating neutrophils are sampled from a population, but when epinephrine is excreted, blood speeds up and the marginal neutrophils join the circulating neutrophils

Front 120

What is seen on a stress leukogram?

Back 120

-leukocytosis
-neutrophilia
-LYMPHOPENIA
-Monocytosis
-Eosinopenia (maybe)

Front 121

What is the difference in length between neutrophila caused by epinephrine and stress?

Back 121

-Epinephrine: short term, transient, 20 mintues

- stress/steroid: long term, severe, hours - days

Front 122

What are causes of a stress leukogram?

Back 122

-severe physical or emotional stress
-hyperadrenocorticism
-iatrogenic

Front 123

What causes the neutrophilia due to stress?

Back 123

-decreased margination
-increased bone marrow release

Front 124

How long do neutrophils stay in the factory and how many divisions take place?

warehouse?

Back 124

-2.5 days with 5 divisions

-2.5 days