Chapter 3-Hematocrit

Question 1

What is hematocrit?

Answer 1

The volume of packed red blood cells in a given volume of blood

Question 2

True or false when measuring hematocrit the tube is centrifuge?

Answer 2

True

Question 3

The Buffy coat between the red blood cells and plasma consist of what

Answer 3

White blood cells and platelets

Question 4

What are some sources of error when measuring hematocrit?

Answer 4

Inadequate centrifugation (falsely high)
Excess EDTA causes cella to shrink

Question 5

What is the rule of three?

Answer 5

RBC x 3 = Hgb +/- 3

HGB x 3 = HCT +/- 3

Question 6

A decrease in the rule of three could mean what?

Answer 6

Anemia

Question 7

An increase in the rule of three could mean what?

Answer 7

Erythrocytosis/polycythemia

Question 8

MCV (Mean cell volume) is?

Answer 8

Average size of a red blood cell 
80 to 100 fl
Less than 80 microcytic
more than 100 macrocytic 
within norms normocytic

Question 9

Causes of a shift in the MCV?

Answer 9

Cold agglutinin,newly transfused cells,reticulocytosis

Question 10

MCH (mean cell hemoglobin) measures what?

Answer 10

The average weight of hemoglobin in a given amount of red cells
27.5 - 33.2 pg

Question 11

MCHC (mean cell hemoglobin concentration) measures what?

Answer 11

The average concentration of hemoglobin in the red blood cells
33-36% normochromic
Less than 33 hypochromic
More than 37 hyperchromic normally spherocytes

Question 12

RDW (red cell distribution width) measures what?

Answer 12

Variation in size and shape of red blood cells on a peripheral smear