BLOOD is a bodily fluid in human that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells. The components of blood include plasma (the liquid portion, which contains water, proteins, salts, lipids, and glucose), red blood cells and white blood cells, and cell fragments called platelets .

Blood plays an important role in regulating the body’s systems and maintaining homeostasis. It performs many functions within the body, including:

Supplying oxygen to tissues, supplying nutrients such as glucose, amino acids, and fatty acids either dissolved in the blood or bound to plasma proteins.

Removing waste such as carbon dioxide, urea, and lactic acid Immunological functions, including circulation of white blood cells and detection of foreign material by antibodies.
Coagulation, which is one part of the body’s self-repair mechanism (blood clotting by the platelets after an open wound in order to stop bleeding).

Regulating body pH. Regulating core body temperature

Hydraulic functions, including the regulation of the colloidal osmotic pressure of blood
Blood transport oxygen and carbon dioxide. Oxygen is needed for cellular respiration to produce energy for the cells. Carbon dioxide in cells changes to carbonic acid which is toxic as it decreases hameoglobin levels.

Haemoglobin carries oxygen molecules through the blood to all living cells so if carbon dioxide is not removed no oxygen will not get to the cells and this will lead to death. Blood also transport hormones. Hormones are important because hormones transmit signals from a group of cells to a group of another cells, where its effect is determined to the pattern of secretion and the response of the receiving tissue. It has a long onset of action than neurons and thus is more suitable for controlling slow processes of the body, e.g. growth, menstural cycle, metabolism regulation

Simple sugars such as glucose. Also included amino acids, fatty acids, glycerol, vitamins and dissolved minerals because human blood is made up of 55 percent plasma and 45 percent blood cells. These digested products are carried by blood plasma.

Blood also transports nitrogenous waste such as urea are by products of protein metabolism. Urea, uric acid, creatinine, bilirubin and ammonium ions are transported by plasma to kidney to be excreted.