Blood Collection Methods

1. Capillary: From the finger (adults) or heel (babies).

2. Vacuum: From the arm, wrist, or foot/toe.

3. Syringe: (Method not detailed).

Blood Components & Circulation

• Veins: Carry deoxygenated blood (CO₂-rich, appears blue).

• Arteries: Carry oxygenated blood (O₂-rich, appears red).

• Capillaries: Site where oxygen (O₂) and carbon dioxide (CO₂) mix and exchange.

Vascular System

• Blood vessels are part of the vascular-nervous package, including veins, arteries, and nerves.

Blood Composition

• 100% Blood Composition:

• 45% Cells (RBC, WBC, Platelets)

• 55% Plasma

• Hemoglobin (Hb)

• O₂ + Hemoglobin = HbO₂

• CO₂ + Hemoglobin = HbCO₂

• HbS (Sickle Cell Hemoglobin): Causes sickle cell disease.

• Blood Cells & Function

• Neutrophils: Fight bacteria.

• Basophils: Respond to viral infections.

• Eosinophils: Fight parasites (possibly allergies too).

Blood Clotting & Lifespan

• Platelet Count for Clotting: (150,000–300,000).

• Liver processes red blood cells, which have a lifespan of ~120 days.

• Old blood cells become damaged and ineffective.

Blood Typing & Compatibility

• A, B, AB, O blood groups:

• AB+ = Universal recipient.

• O- = Universal donor.

• Blood type reaction (+) indicates antigen presence; no reaction (-) means no antigen.

Other Notes

• Bone marrow produces red blood cells.

• Low RBC count can indicate anemia.

• Hematocrit (Hct) = The proportion of red blood cells in blood.