Blood Properties and Functions

Study Notes

Blood is a red fluid within blood vessels, representing 8% of body weight (5 liters in women, 5.5 liters in men).
Specific gravity: 1.060 for whole blood, 1.030 for plasma, 1.090 for blood cells.
Viscosity: 5 times that of water for whole blood, 2 times for plasma.

Plasma: The fluid portion, comprising 55% of blood volume.
Cellular Elements: Comprising 45% of blood volume:
- Red Blood Cells (RBCs): Erythrocytes.
- White Blood Cells (WBCs): Leukocytes.
- Platelets: Thrombocytes.

Transport:
- Carries oxygen to tissues and carbon dioxide to the lungs.
- Transports absorbed nutrients from the gut.
- Transports waste products for excretion (e.g., urea, uric acid).
- Transports hormones and regulatory substances.
Temperature Regulation: Plasma absorbs and distributes heat produced by metabolism.
Hemostasis: Blood clots to stop bleeding and seal injuries.
Defense:
- White blood cells attack invading organisms.
- Antibodies provide immune defense.
Nutrition:
- Provides nutrients for tissues (sugars, amino acids, fatty acids, minerals).
- Plasma proteins can be broken down for extra amino acids.

Fluid portion of blood, comprising 3.5 liters in a 70 kg man (5% of body weight).
Yellow color.
Specific gravity: 1.030.
pH: 7.4.
Viscosity: 2 times that of water.
Osmotic pressure:
- Crystalloid: 5000 mmHg.
- Colloid (proteins): 25 mmHg.

Water: 90%, medium for transport and temperature regulation.
Plasma Proteins: 6-8% of total weight.
Inorganic Constituents: 1% of total weight (Na+, Cl-, HCO3-, K+, Ca2+, Mg+).
Other: Nutrients, waste products, dissolved gases, hormones.

Fluid remaining after blood clots and the clot is removed.
Same composition as plasma but lacks fibrinogen and clotting factors II, V, and VIII.

Important components that remain in the plasma and perform various functions.
Do not pass through capillary pores due to their size.
Exist in a colloidal dispersion.
Total concentration: 6-8 g/dl.
Three groups:
- Albumin: 4-4.5 g/dl.
- Globulin: 2.5 g/dl (subdivided into α1, α2, β1, β2, and γ globulins).
- Fibrinogen: 0.3 g/dl.
Albumin/Globulin (A/G) ratio: 1.2-1.6.