Physiology 2Name

Redwood High SchoolClass Period

Using Complete Blood Cell Counts to Diagnose Disease

Background

A healthy adult has about 4.5 to 5 million red blood cells and approximately 8,000 white blood cells ineach drop of blood. Determining the number of red and white blood cells can assist a healthcare

specialist in the diagnosis of disease. A decrease in the number of red blood cells may indicate a condition known as anemia. A lack of red blood cells means a lack of oxygen, which can lead tosymptoms such as fatigue, headache, paleness, shortness of breath, and even fainting. Thepresence of anemia can help direct a physician to a specific diagnosis. A decrease or increase in thenumber of white blood cells can also indicate a problem. For example, a large increase in whiteblood cells is commonly indicative of an infection.

A complete blood cell count (CBC) is a common procedure performed to determine the number of redand white blood cells in an individual. A hemocytometer is a specialized counting chamber used forblood cell counts. Blood is diluted and added to the surface of the hemocytometer that contains a grid. The number and types of cells located within each square of the grid are counted using amicroscope, and are used to estimate the total amounts in blood. In the following activity, you will usea simulated hemocytometer sample to estimate the red and white blood cell count for your patients. Additionally, you will use simulated blood samples to perform an actual RBC count using hemocytometers and microscopes.

Procedure

Read each patient complaint. A blood smear sample in a hemocytometer grid has been provided, aswell as information on any additional abnormal observations that may help in a diagnosis. Follow thedirections to perform a red blood cell, white blood cell, and platelet count.

Patient 11011

A 16 y/o female was brought into the ER after she fainted while playing in a basketball game. She
has been feeling fatigued and experiencing headaches over the last few weeks.

Patient 22022

A 6 y/o male has been experiencing weight loss, weakness, and fatigue. The parents have beenworried that he has not been hungry and is bruising easily.

Patient 33033

A 71 y/o male was brought into the ER with extreme abdominal pain that is made worse by anymovement. He has been experiencing some abdominal discomfort for the past few months.

Patient 44044

A 26 y/o female has been experiencing fever, headache, sweating, sleepiness, fatigue, and vomiting over the last 2 weeks.

Directions

Procedure – Analyzing Simulated Blood using Hemocytometer/Microscopes

  1. You will work with a partner to complete RBC counts, using the hemocytometers for (2) different samples of simulated blood. You will repeat the same procedures for Sample A and Sample B.
  2. You will have a hemocytometer slide, cover slips, pipette and two beakers with simulated blood labeled Sample A and Sample B. Thoroughly stir the sample and, using the available pipette, immediately withdraw a small amount of simulated blood.
  3. Hold the pipette at approximately 60º angle to the slide and dispense (1) drop at the edge of the cover slip. The sample should be drawn under the cover slip by capillary action and completely cover the counting chamber.
  4. You will count the RBCs from (5) grids on the hemocytometer – each of the four corner grids and the central grid. The grids and the pattern for their count are indicated in the figure below.
  5. When you encounter cells that are touching the grid lines, count any cells touching the top and left lines and do not count cells touching the bottom and right lines. Record your results in Data Table 3.
  6. Repeat steps 4 and 5 for the second counting grid on your slide (on the opposite side of the slide).
  7. Wash and dry the hemocytometer slide, clean the pipette, and get a new cover slip.
  8. Repeat steps 2 to 7 for the second simulated blood sample.

Table 3. Simulated RBC Counts

Sample A
A / B / C / D / E / Average
Count 1
Count 2
RBC/grid
RBC/grid x 105= RBC/mm3
Sample B
A / B / C / D / E / Average
Count 1
Count 2
RBC/grid
RBC/grid x 105= RBC/mm3

Table 4. Results and Diagnosis

Patient / Results / Diagnosis/Explanation
A
B

Analysis

After completing the diagnosis, answer the following questions.

  1. What is a complete blood cell count? How does a hemocytometer help perform a blood cell count?
  1. Research any one of the diagnosed diseases. Briefly discuss the cause, effect and treatment of the condition.