Erythrocytes Flashcards
What kind of erythrocyte is this
Dog:
Uniform size
Central pallor (concave)
What kind of erythrocyte is this
Cat:
Smaller
Anisocytosis (variation in size)
Scarce central pallor (less concave)
What kind of erythrocyte is this
Horse:
Rouleaux formation (clustering of RBCs in standing blood)
Not strong attachment but strong impact on sedimentation time (shorter)
What kind of erythrocyte is this
Ruminant:
Crenation (silky appearance)
Variation in size
What kind of erythrocyte is this
Camelid:
Ellipsoid
How does haemoglobin binding work
In regions of high oxygen concentration (lung) globin releases CO2 & iron binds to O2 (oxyhaemoglobin)
In regions of low oxygen concentration, O2 is released & CO2 bound (carbaminohaemoglobin)
What is erythropoiesis
Continuous process of replenishment
Occurs in red bone marrow & spleen
Formation of erythrocytes requires adequate amounts of:
Protein, iron, copper, folic acid & vitamins
What is erythropoietin and where is it sourced from
Hormone that controls rate of erythrocyte production
Used for doping in horse racing
Source:
Embryonic life
Yolk sac, liver, kidney, spleen & bone marrow
Adult life
Kidney
Label the erythrocyte production diagram
Describe erythrocyte breakdown
As they age:
Lose sialic acid residues from their surface
Exposes galactose moieties that induce their phagocytosis
Become more fragile
May become swollen due to failure of normal membrane function
Normal lifespan in dogs = 120 days
Transfused lifespan much shorter (21 days)
Describe iron metabolism
Free iron is toxic to cells as it acts as catalyst in formation of free radicals from reactive oxygen species
What is PCV
Packed cell volume (PCV):
Measure of volume occupied by red blood cells in given volume of blood
Expressed as percentage
What is hematocrit
Volume of red blood cells as percentage of total blood volume
What is total RBC count
Absolute number of RBC in given volume of blood
Provides information about oxygen carrying capacity of blood
What is haemoglobin concentration
Measures amount of haemoglobin in given volume of blood
Expressed as g/dl or g/L of blood
Reflects oxygen carrying capacity of blood
Important indicator of anemia
Label parts of microhaematocrit
What are the different microhaematocrits showing
What is MCV
Mean cell volume (MCV)
Average volume or size of RBC
MCV = PCV/ total RBC count
Used to classify RBC into categories based on their size to diagnose anemias
Microcytic (small), normocytic (normal), macrocytic (large)
What is MCH
Mean corpuscular hemoglobin (MCH)
Average amount of hemoglobin in single RBC
MCH = total hemoglobin/total RBC count
Helps evaluate type of anemia & classify RBC as hypochromic (low hemoglobin) or normochromic (normal hemoglobin)
What is MCHC
Mean corpuscular hemoglobin concentration (MCHC)
Average concentration of hemoglobin in RBC
MCHC = (total hemoglobin/PCV) x 100
What is anemia
Condition in which capacity of blood to transport oxygen is reduced
Reduced number of circulating erythrocytes
Reduced amount of hemoglobin per erythrocyte
Defined by 3 basic variables
Total hemoglobin
PCV/haematocrit
RBC count
