Notes
Blood Composition and Function
Sections
Overview
Plasma: 55%
Formed Elements: 45%
Plasma Details
Water: 90% of plasma volume
Acts as a transport medium, absorbs and distributes heat.
Proteins: buffer blood pH, osmotic balance between interstitial fluid and blood, produce blood viscosity.
Albumin is the most abundant; contributes to osmotic pressure.
Immunoglobulin plays a role in immune defense.
Fibrinogens are clotting factors.
Electrolytes: buffer blood pH and help maintain blood's osmotic balance, regulate membrane permeability.
Metabolic nutrients: respiratory gases (oxygen), glucose, fatty acids and vitamins
Metabolic waste: respiratory gases (carbon dioxide), urea and uric acid
Hormones
Formed Elements
Erythrocytes: 98-99%
Transport oxygen and carbon dioxide.
Leukocytes (white blood cells): 1-2%
Granulocytes (granules visible after staining):
- Basophils: inflammatory response
- Eosinophils: parasitic infection and allergic reactions
- Neutrophils: most abundant, engulf bacteria
Agranulocytes (granules not visible under microscope):
- Monocytes: engulf bacteria
- Lymphocytes: B and T cells, differentiate in bone marrow and thymus
Platelets: fragments of megakaryocytes, function in hemostasis
Clinical Correlations
Deep Venous Thrombosis (DVT):
Poor blood flow causes clumping of blood fragments
Hemophilia:
Occurs when a genetic mutation causes a clotting factor deficiency