Erythrocytes Flashcards
What is Erythropoeisis?
process of maturation of a RBC
What is the lifespan of a RBC in a Dog?
110 days
What is the lifespan of a RBC in a Cat?
68 days
How are RBC’s classified?
- Cell arangement of blood film
- Color (variation: Polychromasia)
- Size (variation: Anisocytosis)
- Shape (variation: Poikilocytosis)
- Presence of structures
What is Polychromasia?
variation in color
What is Rouleaux Formation?
- grouping of red blood cells in stacks
- sign of increased fibrinogen or globulin concentration
- can be artifact (operator error)
How do you “fix” a Rouleaux Formation?
drop of saline added to blood
What is Agglutination?
- appears as stacks or clusters
- occurs in: immune-mediated disorders
- antibody coats the cell causing clumping
- saline won’t fix
What is Normochromatic?
erythrocytes that are normally colored
What 2 ways can Polychromasia show?
- Hypochromasia
- Hyperchromasia
Polychromatic RBC
- bluish tint (caused by small amt. of nucleus in cytoplasm)
- may appear as reticulocytes
What is Hypochromasia?
- decrease in color
- decreased staining intensity caused by insufficent hemoglobin
- caused by: iron deficency
What is Hyperchromasia?
- cell that appears darker than normal
- oversaturated with hemoglobin
- true hyperchromasia can’t exist!!
What is MCHC?
- mean corpuscular hemoglobin concentration
- describes cell as normochromatic or hypochromatic
What is the normal MCHC?
31-36%
What is Normocyte or Normocytic Cells?
- RBCs that are of normal, consistent size
- Anisocytosis:variation in size
What is Anisocytosis?
- variation in size
- indicates:anemia
- can be microcytic or macrocytic
What is Macrocytosis?
- abnormal amount of cells larger than normal size
- indicate: liver disease and Vitamin B12 deficency
What is Microcytosis?
- abnormal amout of cells that are smaller than normal
- indicates:iron deficency
What is MCV?
- mean corpuscular volume
- describes cells as being normocytic, macrocytic or microcytic
- measures average volume of RBCs
What is the normal values of MCV?
66-77fl (femtoliters)
What is Poikilocytosis?
- major deviation in normal shape of the RBC
- umbrella term
What are Shistocytes?
- fragmented cells
- formed as a result of shearing of the cell by fibrin strands
- occurs when: RBC rapidly pass thru microvasuculature lined or meshed with strands
- observed in hemolysis caused by: DIC, iron deficency
What are Acanthocytes?
- spur cells
- projections vary in length, width and surface distribution
- seen in animals with altered lipid metabolism (hepatic lipidosis, liver disease)
What are Echinocytes?
- burr cell
- have multiple, small, delicate regular shaped spines evenly distributed
- can be artificial
- oven seen with slow drying blood films
- crenation: slow drying blood films, underfilled EDTA tube
- associated with: renal disease, lymphosarcoma, rattlesnake bites
- seen in horses after exercise
What is Crenation?
- artifact
- even membrane projections
- commonly observed in pig blood
What are Drepanocytes?
- sickle cell
- cresent shaped with pointed ends
- often seen in deer and goats
- result of: low oxygen tension
What are Pre-Keratocytes?
- cells with psuedovacuole
- caused when cell bumped into fibrin strand
What are Keratocytes?
- helmet cells
- also called bite cells
- associated with trauma
- psuedovacuole from pre-keratocyte ruptured
What are Spherocytes?
- have a reduced cell membrane strength
- hyperchromatic
- seen most frequently in Immune Mediated Hemolytic Anemia
- usually seen in dogs
What are Dacrocytes?
- tear cells
- seen in myeloproliferative diseases
- can be produced as an artifact
When is a Dacrocyte an artifact?
- when all the tails point in the same direction
- caused by improper blood smear
What are Codocytes?
- umbrella term
- describes cells that have increased membrane surface area
What cells are Codocytes?
- target cell
- folded cell
- stomatocytes
What are Folded Cells?
- have rectangular central palor
- associated with liver disease, acute alcoholism, electrolyte imbalances
What are Stomatocytes?
- resemble smiling mouth
- associated with hereditary diseases, liver disease, electrolyte imbalance
What are Target Cells?
- mainly in dogs
- have increased membrane to volume ratio
- thin bell shaped cells
- indicatd liver disease or hemoglobinopathies
- may be seen as artifact
How is a Target Cell created as an artifact?
-when smears are made in high humidity or blown dry
What are structures found on/in erythrocytes?
- nucleated RBC
- basophilic stippling
- howell jolly bodies
- heinz bodies
- reticulocytes
What are Nucleated Red Blood Cells?
-represent early release of immature RBC during anemia
What is Basophilic Stippling?
- observed in RBCs that contain abnormal aggregation of RNA
- observed in heavy metal poisioning, non regenerative anemia, erythrogenesis
- dogs, cats, ruminants
What are Howell Jolly Bodies?
- nuclear remnants observed in young RBC
- observed in cats and horses
- seen in regenerative anemia
- also seen with spleen disease or spleen removal
What are Heinz Bodies?
- particles of denatured hemoglobin protein
- stain with new methylene blue
- onion toxicity
- acetaminophine toxicity
- spleen lyses cells
What % of Heinz Bodies do cats normally have?
2-3%
What are Reticulocytes?
- immature RBC
- contain organells lost in mature cell
- have 2 types
What are the 2 types of Reticulocytes?
- aggregate
- punctate
What are Aggregate Reticulocytes?
- form large clumps of reticulum
- mature into punctate form within 24 hours
What are Punctate Reticulocytes?
- unique to cats
- contain 2-8 single granules
- circulate for 7-10 days
