The Blood I SPR25

Blood Overview

• Course: ZOOL 352 Spring 205

Blood-related Terms

• Hematology: The study of blood.

• Circulatory System: Composed of blood, blood vessels, and the heart.

• Cardiovascular System: Focuses on blood vessels and the heart.

Functions of Blood

1. Transportation:

   • Nutrients, wastes, gases, hormones, and heat to and from cells.

   • From blood loss: Involves hemostasis and platelets.

   • From pathogens: Involves immune responses by leukocytes.

2. Protection:

   • Maintains pH levels and fluid balance.

   • Aids in thermoregulation (body temperature control).

3. Regulation:

   • Regulates various physiological parameters.

Blood Composition

• Connective Tissue:

  • Contains two main components:

  • Cells (formed elements):

    • Erythrocytes: Red blood cells, responsible for oxygen transport.

    • Leukocytes: White blood cells, essential for immune response.

    • Thrombocytes: Platelets, critical for clotting.

  • Extracellular Matrix (plasma): Liquid component of blood.

Hematocrit Test

• Measures the proportion of red blood cells in blood.

• Components of blood:

  • Plasma: 55% of total blood volume.

  • Erythrocytes: Approximately 45% of total blood volume.

  • Buffy Coat: Contains leukocytes and platelets.

• Reference Values:

  • Children (up to 5 years): Hemoglobin (11.0 g/dL), Hematocrit (33%)

  • Children (5-11 years): Hemoglobin (11.5 g/dL), Hematocrit (34%)

  • Nonpregnant women: Hemoglobin (12.0 g/dL), Hematocrit (36%)

  • Pregnant women: Hemoglobin (11.0 g/dL), Hematocrit (33%)

  • Men: Hemoglobin (13.0 g/dL), Hematocrit (39%)

Plasma Characteristics

• Description: Sticky, yellow-colored substance.

• Solvent: Primarily water, containing over 100 solutes including:

  • Proteins

  • Nutrients

  • Electrolytes

  • Hormones

  • Gases

  • Wastes

Plasma Proteins

• Albumins:

  • Smallest and most abundant plasma proteins.

  • Act as pH buffers and transport solutes.

  • Produced by the liver.

• Globulins (3 types):

  • Role in transporting solutes and clotting (e.g., prothrombin).

  • Produced by the liver.

  • Types:

    • Alpha: Involves solute transport and immunity (complement proteins).

    • Beta: Antibodies or immunoglobulins (Ig) secreted by plasma cells.

    • Gamma: Involved in immune response.

• Fibrinogen:

  • Protein precursor produced by the liver.

  • Activated to form fibrin, which is essential for clot formation.

  • Plasma without fibrinogen is known as serum.

Related Blood Properties

• Viscosity:

  • Describes the "stickiness" of blood and its resistance to flow.

  • Influenced by:

    1. Concentration of plasma proteins.

    2. Packed Cell Volume (PCV).

    3. Temperature.

  • Higher viscosity can lead to increased blood pressure.

• Osmolarity:

  • Concentration of solutes in blood; low osmolarity results in "thin, watery blood" leading to swelling (edema).

Application: Liver Disease

• Healthy Liver vs. Disease: Fibrosis, Cirrhosis, Carcinoma.

• Symptoms: Ankle edema, ascites.

Waste Products in Plasma

• Urea

• Uric Acid

• Creatinine: Nitrogenous wastes that reflect renal function.