Blood

? Definition of blood: is a specialized connective tissue consisting of cells and cell fragments (46% of blood volume) floating in a unique liquid extracellular matrix (54% of blood volume).

? Compositions:
Component Significant
Red blood cells (RBC) Transport gases (oxygen and carbon dioxide)
White blood cells (WBC) Defend body against pathogens, remove toxins, wastes, and damaged cells.
Platelets Participate in clotting response derived from megakaryocytes in the bone marrow
Plasma
Water (90%) Dissolves and transport organic and inorganic molecules, distributes blood cells, and transfers heat.
Electrolytes Normal extracellular fluid ion composition essential for vital cellular activities.
Nutrients Used for energy production, growth, and maintenance of cells.
Organic wastes Carried to sites of breakdown or excretion.
Proteins (8-9)%
1. Albumins Major contributor to osmotic concentration of plasma, transport some lipids
2. Globulins Transport ions, hormones, and lipids
3. Fibrinogen Essential component of clotting system, can be converted to insoluble fibrin.
Serum Yellowish fluid remaining after blood has clotted.


? Functions of blood:
1. Transport of dissolved gases, brining oxygen from lungs to the tissues and carrying carbon dioxide from the tissues to the lungs.
2. Distribution of nutrients absorbed the digestive tract or released from storage in adiposed tissues or the liver.
3. Transport of metabolic wastes from peripheral tissues to sites of excretion, especially the kidneys.
4. Stabilization of the pH and electrolytes composition of interstitial fluids through the body.
5. Prevention of fluid losses through damaged vessels or at other injury sites.
6. Defense against toxins and pathogens.
7. Delivery of enzymes and hormones to specific target tissues.
8. Stabilization of body temperature by absorbing and redistributing heat.