Blood/Components

Overview of Blood

  • Discussion begins with emphasis on the complexity and speed of blood studies.

  • Instructor encourages students to practice skills like taking blood pressure, highlighting the importance of systematic examination from head to toe.

Blood Examination Procedures

  • Head-to-Toe Assessment

    • Importance of a systematic approach in patient examination.

    • Instructor prefers starting with central areas before peripheral areas, performing all anterior assessments followed by posterior ones.

    • Focused on patient comfort, especially those with breathing difficulties.

Blood Terminology

  • Suffixes and Prefixes Related to Blood

    • Hemo/Hemat: Relates to blood.

    • Ending in "-emia" indicates conditions associated with blood.

Example: Polycythemia

  • Poly: Means multiple.

  • Cyto: Refers to cells.

  • Polycythemia Defined: Condition of having an overabundance of red blood cells.

Blood Volume and Characteristics

  • Average adult holds about 5 liters of blood.

  • Potential for rapid blood loss in case of severe injury, leading to loss of consciousness within seconds.

    • Severity depends on the impacted blood vessel, specifically large vessels like the aorta which can be dislodged in accidents.

Nature of Blood

  • Connective Tissue: Blood is classified as connective tissue, circulating in vascular pathways.

  • Functionality of Blood:

    • Circulation is vital for oxygen delivery and carbon dioxide removal.

    • Red blood cells are akin to a "Life Raft" delivering oxygen efficiently throughout the body.

Dynamics of Oxygen Transport

  • Oxygen is delivered based on the laws of diffusion:

    • Natural flow is from areas of high concentration (oxygen-rich) to low concentration (oxygen-depleted).

    • Cycle: Red blood cells deliver oxygen to tissues, then return to lungs to pick up more oxygen.

Components of Blood

  • Red Blood Cells (Erythrocytes)

    • Primary function: Oxygen transport.

  • White Blood Cells (Leukocytes)

    • Combat infections through various types:

    • Different kinds to tackle various pathogens.

    • Antibodies: Proteins that identify pathogens and assist in eliminating them (e.g., COVID antibodies).

  • Platelets

    • Responsible for blood clotting; they aggregate and form clots to prevent excessive bleeding.

Blood Functions

  • Transport System

    • Delivers oxygen and nutrients.

    • Removes waste products including carbon dioxide.

    • Circulates hormones and enzymes.

  • Regulatory Functions:

    • Maintains acid-base balance.

    • Regulates body temperature through dilation and constriction of blood vessels.

Blood Composition and Structure

  • When blood is separated via centrifugation:

    • Plasma:

    • Makes up approximately 55% of blood volume.

    • Carries water, proteins (e.g., albumin), electrolytes (sodium, potassium), gases, nutrients, enzymes, and hormones.

    • Its role is vital for fluid balance and transport of medications.

    • Buffy Coat:

    • Consists of white blood cells; approximately 1% of blood volume.

    • Erythrocytes:

    • Red blood cells, accounting for about 45% of blood volume.

  • Hematocrit: Measurement of the percentage of blood that consists of formed elements (red blood cells).

Blood Viscosity

  • Blood should ideally have a thin consistency: thicker than water but not sludgy.

  • High Viscosity Issues:

    • Blood that's overly concentrated (such as in diabetics) can lead to circulation issues, clogs in small vessels (e.g., in eyes, feet, kidneys).

    • Can result in serious complications like blindness and kidney failure requiring dialysis.