Download - Peripheral Smear
Peripheral Smear
Sarmishtha Ghosh
Physiology
CBC
• TOTAL RBC COUNT
• TOTAL WBC COUNT
• PERIPHERAL SMEAR– SHAPE, SIZE & COLOR OF RBCs– DIFFERENTIAL WBC COUNT– PLATELET COUNT
• HEMOGLOBIN CONCENTRATION
• BLOOD INDICES – MCH, MCV, MCHC
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4
2
3
Normal RBC distribution
HEAD- TOO THICK, SMALL & HYPOCHROMIC
TAIL- TOO THIN, MACROCYTIC & FLAT
SHAPE
HEMOGLOBIN CONTENT & DISTRIBUTION
WHITE BLOOD CELLS- LEUCOCYTES
NEUTROPHIL
EOSINOPHIL
BASOPHIL
LYMPHOCYTE
MONOCYTE
Hemocytometer
Blood Indices
• The relationships between the hematocrit, the hemoglobin level, and the RBC are converted to red blood cell indices through mathematical formulas.
• These formulas were worked out and first applied to the classification of anemias by Maxwell Wintrobe in 1934.
• The indices include these measurements: mean corpuscular volume (MCV); mean corpuscular hemoglobin (MCH); mean corpuscular hemoglobin concentration (MCHC); and red cell distribution width (RDW). They are usually calculated by an automated instrument as part of a complete blood count (CBC).
Mean corpuscular volume (MCV)
• MCV is the index most often used. • It measures the average volume of a red blood
cell by dividing the hematocrit by the red blood cell count.
• The MCV categorizes red blood cells by size.
• Cells of normal size are called normocytic, smaller cells are microcytic, and larger cells are macrocytic. Following formula is used to calculate MCV
Mean corpuscular hemoglobin concentration (MCHC)
• measures the average concentration of hemoglobin in a red blood cell.
• This index is calculated by dividing the hemoglobin by the hematocrit. The MCHC categorizes red blood cells according to their concentration of hemoglobin.
– Cells with a normal concentration of hemoglobin are called normochromic;
– cells with a lower than normal concentration are called hypochromic.
– Because there is a physical limit to the amount of hemoglobin that can fit in a cell, there is no hyperchromic category.
• Anemias are categorized as hypochromic or normochromic according to the MCHC index.
Mean corpuscular hemoglobin (MCH)
• The average weight of hemoglobin in a red blood cell is measured by the MCH.
• Anemias are categorized as hypochromic or normochromic or hyperchromic according to MCH index.
• MCH is most useful in diagnosis of severely anemic patients. Among those with lesser degrees of anemia, it is less useful because the measurement has a potential for a relatively wide range of error.
• MCH (in pg) = hemoglobin (in g/dL) x 10 ÷ RBC count (in millions/mm3)
Normal results for red blood cell indices are as follows:
• MCV 82 to 98 fl (femtoliters)
• MCHC 31 to 37 g/dl (or %)
• MCH 26 to 34 pg (picograms)
LAB EXERCISES
References cellbio.utmb.edu/microanatomy/Blood.htm
Constructed by:Dr. Sarmishtha Ghosh
MBBS2012
IDENTIFY WITH JUSTIFICATION : a,b,c,d1
a b c de f
2
• 1) What is the advantage of the biconcave shape of RBCs?
• 2) Why is the absence of a nucleus an advantage?
3
R- Red Blood Cell
N- Neutrophil
E- Eosinophil
• 1) What is the function of N & E respectively?
• 2) The eosinophil count of a patient is 7%. What might be the probable indications?
4
R- Red Blood Cell
N- Neutrophil
E- Eosinophil
• Identify “X”.
• What is it composed of?
• What is its function in the body?
X
5
• The photograph shows a Monocyte
• What made you identify it to be a Monocyte?
• Where would you expect monocytes to be in an infection?
• What is their function?
6
• These cells in the are 25-33% of white blood cells.
• What is it and what is its function?
7
• Identify Cell # 1
• Identify Cell # 2
• Identify Cell # 3
8
•This is a Lymphocyte.
•State the Identifying features
•Is this a T lymphocyte or a B- lymphocyte
9
Comment on RBCs in the three slides A,B and C.
10 A
B C