John's blood test report indicates a high toxin level is that reabsorption or secretion

It is due to secretion process that John's blood contains high amount of toxin.

If the secretion is not proper, it leads to high amount of toxins in blood.

The organs system which is involved in removal of waste product from the body is called as excretory system. Kidney is the major organ of excretory system. The nephron is considered as the structural as well as functional unit of kidney.  

Every nephron starts with a filtration part that channels the blood entering the kidney. This filtrate at that point streams along the length of the nephrons, which is a cylindrical structure lined by a solitary layer of specific cells and encompassed by vessels.

Such type of arrangement is involved in sending back the required substance into the body by process called reabsorption, and sending the wastes out the body through process called secretion.

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