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
Functions of Neutrophils:
- 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.
Functions of Eosinophils:
- 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.
Functions of Basophils:
- It Secretes 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.
Functions of Lymphocytes:
- 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.
Functions of Monocytes:
- 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 Secretes 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