FUNCTIONS OF BLOOD
- Blood acts as an oxygen carrier from lungs to the body tissues for metabolic activities.
- It carries back CO2 and waste products to remove through excretory organs – Lungs, Kidney, and Skin.
- Blood supplies nutrients to all parts of the body.
- It transports the hormones from the endocrine glands to the target body tissues.
- It carries vitamins to the body tissues.
- Blood helps in the regulation of body temperature.
- Blood helps in maintaining body fluid volume and its balance in the body.
- It maintains the electrolyte balance in the body fluids.
- Blood has a protective function through –
- Leukocytes, or white blood cells – destroy invading microorganisms and cancer cells.
- Antibodies and other proteins destroy pathogenic substances.
- It carries various enzymes to the body tissues for various specific and vital functions in the body.
- It contains thrombocytes which help in the control of loss of blood from the body through injuries.
FUNCTIONS OF RED BLOOD CELLS or ERYTHROCYTES
- RBC’s provides gaseous exchange between tissues and environment as follows –
- Red blood cells due to their hemoglobin content act as the oxygen carrier to all the body tissue.
- Carries carbon dioxide from the body tissues to the lungs for excretion.
- Hemoglobin acts as an important buffer and helps to maintain normal blood pH.
- RBC’s helps to maintain ionic balance.
- It maintains blood viscosity.
- RBC’s maintains the osmotic relationship with plasma.
FUNCTIONS OF WHITE BLOOD CELLS or LEUKOCYTES
- It forms the first line of defense against the pathogens.
- They play roles in the destruction of bacteria and the release of chemicals that kills or inhibit the growth of bacteria – phagocytosis.
- They attack the parasites that are too large to be engulfed by phagocytosis.
- Eosinophilic granules release chemicals which are toxic to the larvae of parasites.
- It collects at the side of allergic reaction and limits their intensity.
- It Secrete histamine which increases tissue blood flow via dilating the blood vessels
- It also secretes heparin which is an anticoagulant that promotes mobility of other blood cells by preventing clotting.
- Lymphocytes function in destroying cancer cells, cells infected by viruses, and foreign invading cells.
- They also coordinate the actions of other immune cells, secrete antibodies and serve in immune memory.
- They form the second line of defense against any pathogen.
- They function in differentiating into macrophages, which are large phagocytic cells, and digest pathogens, dead Neutrophils, and the debris of dead cells.
FUNCTIONS OF THROMBOCYTES or PLATELETS
- Platelets Secrete vasoconstrictors – histamine and 5HT – which constrict blood vessels, causing vascular spasms in broken blood vessels.
- It Forms temporary platelet plugs to stop bleeding.
- Thrombocytes dissolve the blood clots when they are no longer needed
- It Secrete chemicals that attract Neutrophils and monocytes to sites of inflammation
- Platelets Secrete growth factors and have adhesive property by which it maintains the linings of blood vessels