Complete Blood Count PSI AP Biology

Transcription

1 Complete Blood Count PSI AP Biology Name: Objective Students will examine how the immunological response affects molecules in the blood. Students will analyze three complete blood counts and create diagnoses based on them. Standard Essential Knowledge: 2D1a : Cell activities are affected by interactions with biotic and abiotic factors. 2D4 : Plants and animals have a variety of chemical defenses against infections that affect dynamic homeostasis. Materials Every student needs: Activity worksheet Procedure 1. Read the worksheet. 2. Answer the Analysis and Application questions.

2 Complete Blood Count Cells are affected by a variety of biotic and abiotic factors. Examples of abiotic factors include temperature, ph, and water availability. Biotic factors include pathogens that enter and/or attack an individual. When this occurs, the immune system creates a response that defends the body against the pathogen. During an immunological response, the levels of different molecules in the blood will change in response to the specific pathogen. By analyzing the molecules in the blood, medical professionals assess the health of their patients. This type of analysis is called a Complete Blood Count, or CBC. A CBC analyzes red blood cells (erythrocytes), white blood cells (leucocytes), and platelets (thrombocytes). Erythrocytes deliver oxygen throughout the body Red Blood Cell count (RBC) a count of the actual number of red blood cells in a sample Hemoglobin (Hb) a count of the hemoglobin in the sample Leucocytes cells of the immune system that defend the body against infection White Blood Cell count (WBC) a count of the actual number of white blood cells in a sample White blood cell differential count the different types of white blood cells o Neutrophils target bacteria and fungi; act as macrophages o Lymphocytes associated with B cells, T cells and natural killer cells (release antibodies and attack viruses and tumor cells) o Monocytes differentiate into macrophages that engulf pathogens o Eosinophils target larger parasites o Basophils release histamine for the inflammatory response Thrombocytes important for the formation of blood clots Platelet count a count of the actual number of platelets in a sample

3 The following chart details conditions that would cause abnormal counts for each of the above blood counts. Test Full Name Low Values High Values RBC Red blood cell count Called anemia. Acute/chronic bleeding Nutritional deficiency Bone marrow disorder Kidney failure Called polycythemia. Dehydration Pulmonary disease Smoking Hb Hemoglobin Anemia Usually mirrors the RBC results. WBC White blood cell count Called leukopenia. Bone marrow disorders Autoimmune conditions Severe infections (sepsis) Immune system diseases (ex. HIV) Called leukocytosis. Bacterial/viral infection Inflammation Leukemia Allergies, asthma Neu Neutrophils Called neutropenia. Sepsis Autoimmune disorder Leukemia Lymph Lymphocytes Called lymphocytopenia. Autoimmune disorders Infections Mono Monocytes One low count is not medically significant. Called neutrophilia. Acute bacterial infection Inflammation Called lymphocytosis. Acute viral infections Certain bacterial infections (pertussis, tuberculosis) Toxoplasmosis Chronic inflammatory disease Chronic infection Infection of the heart Eos Eosophils Numbers are normally low. Allergies, asthma Parasitic infections Inflammatory disorders Baso Basophils Numbers are normally low. Rare allergic reactions Inflammation Plt Platelet count Called thrombocytopenia. Viral infection Cirrhosis Sepsis Leukemia Called thrombocytosis. Rheumatoid arthritis IBS

4 Analysis For the following three cases, read the patient s description and analyze the CBC to make a diagnosis about what is causing the different cell densities. 1. Patient Description 17-year-old female is suffering from shortness of breath and exhaustion. Last year she was the MVP on her cross country team but this year she is having trouble finishing practice. CBC Test Result Normal Range RBC Hb WBC Neu Lymph Mono Eos Baso Plt Diagnosis: Why?

5 2. Patient Description Middle aged male is complaining about itchy, watery eyes, exhaustion, congestion, and body aches. CBC Test Result Normal Range RBC Hb WBC Neu Lymph Mono Eos Baso Plt Diagnosis: Why? 3. Patient Description A stay-at-home mom has a high fever and is complaining of a severely sore throat. CBC Test Result Normal Range RBC Hb WBC Neu Lymph Mono Eos Baso Plt Diagnosis: Why?

6 Application 1. Why is it important to analyze the CBC as well as the patient description? 2. Explain how a low hemoglobin count can cause a person to have trouble running. 3. How does an animal s immune system usually fight bacterial pathogens? How would this show up on a CBC? 4. Should antibiotics be given for a viral infection? Why or why not?