Erythrocytes

Question 1

erythropoiesis

Answer 1

formation of red blood cells
kidneys control secretion of EPO

Question 2

how can erythropoietin effect red blood cell numbers?

Answer 2

anemia causes low O2 capacity of the RBCs and decreased tissue oxygenation
kidneys increase EPO secretion and stimulates RBC production which brings the RBC concentration back into normal range

Question 3

hemoglobin

Answer 3

synthesized during RBC maturation
components: heme (iron), globin (amino acids)
Hgb bound to O2 = oxyhemoglobin

Question 4

red blood cell maturation

Answer 4

rubriblast —> prorubricyte —> rubricyte —> metarubricyte —> polychromatophil/reticulocyte —> erythrocyte

Question 5

when does the nucleus get taken out of a red blood cell?

Answer 5

between the metarubricyte and polychromatophil phases
polychromatophils don’t have a nucleus

Question 6

when would a polychromatophil be called a reticulocyte?

Answer 6

when seen in a new methylene blue stain

Question 7

corrected white blood cell count

Answer 7

must correct white blood cell count when 5 or more nRBCs are present in the differential
machines count all cells with nuclei so it will count nRBCs as WBCs

Question 8

nRBC

Answer 8

nucleated red blood cell

Question 9

formula for corrected white blood cell count

Answer 9

(WBC x 100) / (100 + nRBC)

Question 10

polychromatophils characteristics

Answer 10

larger than mature erythrocytes
no nucleus
blue-red cytoplasm
has less hemoglobin (more RNA)

Question 11

polychromasia

Answer 11

presence of polychromatophils

Question 12

reticulocytes

Answer 12

polychromatophils stained with new methylene blue
reticulocyte count used to quantify anemia

Question 13

erythrocyte life span

Answer 13

~50-150 days
cat: 68
dog: 110
cattle: 160
horse: 120
since cats have a shorter erythrocyte lifespan they can get anemic faster

Question 14

what type of animals have a shorter erythrocyte lifespan?

Answer 14

smaller animals with faster metabolic rates

Question 15

how are old or damaged red blood cells removed?

Answer 15

destroyed by splenic macrophages

Question 16

mammalian erythrocyte morphology

Answer 16

round and biconcave with a central pallor (can be difficult to discern in cats)
they are also anucleated when mature

Question 17

normocytic

Answer 17

normal erythrocyte size

Question 18

macrocytic

Answer 18

large erythrocyte size
means high MCV

Question 19

microcytic

Answer 19

small erythrocyte size
means low MCV

Question 20

anisocytosis

Answer 20

cells of different sizes in the same sample

Question 21

normochromic

Answer 21

normal erythrocyte color

Question 22

hypochromic

Answer 22

ghost cells
have less hemoglobin = low MCHC
have increased central pallor
caused by defective or inhibited Hgb production

Question 23

hyperchromic

Answer 23

high MCHC
artifact

Question 24

torocytes

Answer 24

punched-out cells
artifact

Question 25

poikilocytosis

Answer 25

cells of different shape in the same sample general term, use specific terms if possible

Question 26

echinocytes

Answer 26

short, pointy, evenly spaced projections "Burr cell": elongated, may be more blunt can be caused by crenation (artifact), electrolyte imbalance, renal disease, snake bite

Question 27

acanthocytes

Answer 27

irregular, blunt, even projections caused by altered metabolism, liver disease, vascular abnormalities

Question 28

keratocytes

Answer 28

"blister cells", "helmet cells" vacuole or blister horn-like projections localized damage to cell membrane caused by anemia or liver disease

Question 29

leptocytes

Answer 29

increased membrane stomatocytes and codocytes

Question 30

stomatocytes

Answer 30

slit shaped central pallor caused by artifact or membrane damage

Question 31

codocytes

Answer 31

target cells central area of pigment surrounded by a clear ring large numbers of codocytes seen in liver disease small numbers of codocytes seen in healthy blood or anemia

Question 32

schistocytes

Answer 32

sheared or fragmented cells are ripped apart by fibrin strands DIC: disseminated intravascular coagulopathy often seen with a thrombocytopenia

Question 33

spherocytes

Answer 33

spherical, microcytic no central pallor stains darker difficult to identify in cats partially phagocytized by macrophages and healed immune mediated hemolytic anemias (IMHA)

Question 34

dacryocytes

Answer 34

tear-drop shaped if all of them are pointed the same way it's probably just an artifact otherwise can be caused by myelofibrosis or myeloproliferative disorders

Question 35

drepanocytes

Answer 35

sickle cells crescent shaped normal in deer and some sheep and goat breeds otherwise it's a mutation in the hemoglobin structure

Question 36

howell-jolly bodies

Answer 36

small, basophilic, and round they're nuclear remnants and will stain like a nucleus normal in small numbers in cats caused by partial removal of the nucleus by splenic macrophages or regenerative anemia more common after splenctomy

Question 37

heinz bodies

Answer 37

rounded protuberance on cell surface stains pale in diff quick stains blue in NMB denatured hemoglobin seen in small numbers in healthy cats caused by diabetes, hyperthyroidism, lymphoma in cats, toxins (red maple leaves in horses, onions, drugs)

Question 38

basophilic staining

Answer 38

small, dark blue specks in the cytoplasm residual RNA in cytoplasm seen in immature cells of ruminants (regenerative anemia) caused by lead toxicity

Question 39

rouleaux

Answer 39

cells stacked like coins common in healthy horses and cats often an artifact caused by increased fibrinogen or globulins

Question 40

agglutination

Answer 40

clusters or clumps of erythrocytes can be seen in immune mediated hemolytic anemia (IMHA) do saline test to make sure it's agglutination: add saline to a drop of blood, true agglutination will survive a 1:5 of blood to saline

Question 41

platelets/thrombocytes life cycle

Answer 41

megakaryoblast ---> megakaryocyte ---> megakaryocyte breaks into platelets

Question 42

primary hemostasis

Answer 42

activated platelets form a platelet plug part of the mechanical phase occurs within minutes

Question 43

secondary hemostasis

Answer 43

reinforcement of the frail platelet plug with fibrin strands part of the chemical phase occurs within hours

Question 44

fibrinolysis hemostasis

Answer 44

clot dissolves after vascular wall repair occurs within days