Human Blood

Human Blood

• Blood is a specialised body fluid that delivers necessary substance to various cells like nutrients and oxygen and transports waste products away from those cells. Blood accounts for 7% of human body weight. The average human adult has a blood volume of approximate  5 litres.Arteries carry inhaled oxygen rich blood from the heart to the tissues while veins carry carbon dioxide rich blood deoxygenated from the tissues to the lungs to be in exhaled.

Composition of Blood

• Blood is made up of plasma, red blood cells, white blood cells including leukocytes and platelets. Plasma constitutes about 50 4.3 % of blood RBCs 45% and WBCS about 7%.
• RBCs contain haemoglobin and distribute oxygen to tissues.Leukocytes attack and remove pathogens and provide immunity.
• Platelets are responsible for clotting of blood.
• Plasma is the blades liquid medium.its circulates dissolved nutritions and removes waste products, it is yellow in colour.

Functions of blood

• Supply oxygen to tissues.
• Supply nutrition such as glucose, amino acids and fatty acids.
• Remove is such as carbon dioxide, urea and lactic acid.
• Provide immunity against pathogens.
• Coagulation.
• Transport hormones.
• Regulate Ph.
• Regulate core body temperature.