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Introduction

Blood Blood can be defined as: the circulating fluid (plasma) and suspended formed elements, such as red blood cells, white blood cells and platelets in the vascular system of humans and other vertebrates. This essay will mention about structure of the blood and the functions of the blood. Structure of blood has four major parts these are: plasma, red blood cells, white blood cells, and platelets. Plasma is mainly made up from water; nearly %90-%92 is water. This is a straw coloured fluid.

Middle

They only exist for 120 days in body and there are approximately 4.5 - 5.8 million erythrocytes per micro-litre of healthy blood. This quantity depends on gender and age. White blood cells also named as leucocytes. There are different types of leucocytes. These can be defined as; granular and agranural. Depending on their types, they sometimes exist for few hours to few days but sometimes they can exist for many years. Platelets also called as trombocytes. These are granular and disk-shaped cell fragments.

Conclusion

Blood also carries nutrients for our body cells. There are too many reactions happen in our body with the help of enzymes and these enzymes need optimum conditions to work well. One of these optimum conditions is: pH and pH is controlled by blood. Toxins are harmful for our body when the blood takes waste products from our cells than it goes to kidney. Kidney filters the blood and the toxins that filtrated from the blood are removed from the body in the form of urine. Blood plays a very important role in our body. It has very important functions and specialized structure to do them. Blood have a vital job in our body, without blood we could not exist.