study questions wk 4 Flashcards
Erythropoietin
A cytokine responsible for the production of RBCs
Where and why is EPO produced?
In the kidneys in response to decrease in oxygen tension in the blood
normal canine RBC
biconcave disc shape with an area of central pallor
normal feline RBC
Round with little to no area of central pallor
5 categories for morphologic characteristics of erythrocytes
a. Cell arrangement
b. Size
c. Color
d. Shape
e. Presence of structures in or on the erythrocyte
Rouleaux
stacking of erythrocytes; artifact; normal in horses - may be in dogs or cats; disperses in saline
Autoagglutination
occurs in immune-medicated disorders; cells coat with antibodies resulting in bridges and clumps; differentiate from rouleaux with a drop of saline
Anisocytosis
variation in cell size
Polychromasia
bluish tint in cells
Hypochromasia
decreased color
Hyperchromatophilic
darkly stained; too much color
Poikilocyte
abnormally shaped; general term
Schistocyte
RBC fragments; half of cell is gone
Acanthocyte
spur cells; spiky and bumps
Echinocyte
burr cells; lots of spikes; artifactual
Drepanocyte
sickle cells; ice/frozen over look
Keratocyte
helmet cells; blister cells; vacuole/white bubbles; cancer
Spherocyte
small, dark staining with reduced or no central pallor; red orange spheres; a little smaller than normal
Leptocyte
target cells; general term
Stomatocyte
folded cells; artifacts; white line down center
Knizocyte
Barr cells; dark slit/opening
Eliptocyte
ovalcytes; oval
Eccentrocytes
diabetic; darker on one side - similar to helmet cells
Dacrocyte
teardrop; artifact
Basophilic Stippling
Presence of small, dark-blue bodies, Residual RNA,
Immature RBCs of ruminants, Cats responding to anemia, Lead poisoning
Howell-Jolly Bodies
Basophilic nuclear remnants in young RBCs in response to anemia, Removed when passed through spleen, Increased numbers = splenic disorders
Heinz bodies
Round blue structures—denatured hemoglobin, Caused by oxidant drugs and chemicals
What is the minimum number of oil immersion fields to count for a platelet estimate?
10
Platelet clumping is common in mammals
true
What does the presence of megathrombocytes suggest?
early release of platelets from the bone marrow
What is the formula for determining a platelet estimate?
-Total the number of platelets counted divide by 10
-Multiply the estimated platelet number by 20,000
Average platelets/oif X 20,000 = estimated platelets/ul
