Physiology Blood Analysis Exercise 11

Blood Analysis Overview

Blood consists of two main components: plasma and cellular elements.

Plasma

Composition

• Water: The primary component, making up about 90-92% of plasma, serves as a solvent and helps in the transport of nutrients and wastes.

• Organic Molecules: Includes hormones, metabolites, and nutrients such as amino acids, fatty acids, and glucose which are vital for energy and cellular function.

• Ions: Includes sodium, potassium, calcium, bicarbonate, and magnesium, which are essential for nerve function, muscle contraction, and maintaining fluid balance.

• Proteins: Composed of approximately 7-8% of plasma, includes:

  • Globulins: Function in immune responses (antibodies) and transport of lipids and fat-soluble vitamins.

  • Fibrinogen: Converts to fibrin in the clotting process, crucial for healing after injury.

  • Transferrin: Main protein for iron transport, regulating iron levels in the body.

  • Albumins: Maintain osmotic pressure and transport hormones and drugs.

• Blood Gases: Includes Oxygen (O2) which is essential for cellular respiration, and Carbon Dioxide (CO2) which is produced as a metabolic waste product.

• Nitrogenous Waste: Byproducts such as urea and creatinine from protein metabolism, which are filtered by the kidneys.

• Trace Elements & Vitamins: Necessary for enzymatic reactions and metabolic processes; deficiencies can lead to various health issues.

Cellular Elements

Overview

Composed of:

• Red Blood Cells (RBCs):

  • Role: Transport oxygen from the lungs to tissues and carbon dioxide back to the lungs.

  • Lifespan: Approximately 120 days; produced in the bone marrow.

  • Hemoglobin: The protein in RBCs that binds oxygen.

• White Blood Cells (WBCs):

  • Role: Part of the immune system, fighting infections and foreign invaders.

  • Lifespan: Varies from hours to years, depending on the type.

Types of WBCs:

• Lymphocytes:

  • Function: Responsible for specific immune responses; includes B cells (produce antibodies) and T cells (destroy infected cells).

• Monocytes:

  • Function: Differentiate into macrophages that engulf and digest pathogens and debris through phagocytosis.

• Neutrophils:

  • Function: The most abundant WBCs, first responders to sites of infection, and highly effective phagocytes.

• Eosinophils:

  • Function: Attack larger parasites and are involved in allergic reactions.

• Basophils:

  • Function: Involved in inflammatory responses and release histamine and other chemicals during allergic reactions.

• Platelets:

  • Role: Cell fragments essential for blood clotting; aggregate at sites of vascular injury to form a plug and release chemicals that promote healing.

Hematocrit (Hct)

Definition and Importance

• Definition: Hct measures the proportion of blood volume that is occupied by RBCs; critical for assessing oxygen-carrying capacity.

• Normal Ranges:

  • Males: 42% to 52%

  • Females: 37% to 47%

• Abnormal Conditions:

  • Anemia: Decreased Hct indicating low RBC count or blood loss.

  • Polycythemia: Increased Hct often due to dehydration or conditions causing increased RBC production.

Complete Blood Count (CBC)

Purpose and Key Measurements

• A CBC provides a comprehensive overview of the blood components and is used for diagnosing various conditions.

• Key Measurements:

  • Mean Corpuscular Volume (MCV): Average volume of a red blood cell, indicating size.

  • Mean Corpuscular Hemoglobin (MCH): Average amount of hemoglobin per RBC, reflecting oxygen-carrying capacity.

  • Mean Corpuscular Hemoglobin Concentration (MCHC): Average concentration of hemoglobin in a given volume of packed RBCs.

• Normal Ranges from CBC:

  • Hematocrit: Males 42-52%, Females 37-47%

  • Hemoglobin (g Hb/dL): Males 14-17, Females 12-16

  • Red Cell Count (cells/µL): Males 4.5–6.5 × 10^6, Females 3.9–5.6 × 10^6

  • Total White Count (cells/µL): 4–11 × 10^3 for both genders.

  • Differential White Cell Count %:

    • Neutrophils: 50–70%

    • Eosinophils: 1–4%

    • Basophils: less than 1%.

Lipid Panel (Additional Specimen Testing)

• Cholesterol Levels:

  • Total Cholesterol (mg/dL):

    • Desirable: < 200 mg/dL

    • Borderline High: 200-239 mg/dL

    • High: > 240 mg/dL

  • LDL (Low-Density Lipoprotein) Levels:

    • Optimal: < 100 mg/dL

    • High: > 140 mg/dL

    • At Risk (chronic disease): < 70 mg/dL

  • HDL (High-Density Lipoprotein) Levels:

    • Optimal: > 60 mg/dL

    • Risk for CVD: Males < 40 mg/dL, Females < 50 mg/dL