 Did you know in the next 60 seconds 1.2 liters of blood will be filtered through your kidneys? The blood contains urea which is a waste product formed from the breakdown of excess protein in the body Need to get rid of this urea as it is toxic to the body if it pulls up The job of the kidneys is to filter out the urea along with the excess water and ions and excrete them from the body in the urine So how does the kidneys do this? Well, each kidney is actually made up of about a million microscopic poultry units called nephrons As the blood flows into the kidney in the renal artery it splits into smaller and smaller arteries These eventually become capillaries. Each capillary then forms a bundle called glomerulus The blood is now under very high pressure and the glomerulus has little pores in it that allows the parts of the blood to be squeezed out The water, glucose, amino acids, ions and urea all get squeezed out of the collected Biostructure at the beginning of the nephron called the Bowman's capsule and they are now referred to as the Fultrate The blood cells and large proteins stay in the capillary as they are too big to be squeezed out This process is called ultra filtration The nephron is a quill tube that moves through the kidneys As the Fultrate passes along anything that the body needs to keep is taken back into the blood by a process called selective Reabsorption. However, the blood does not want the urea so it carries it moving through the nephron and eventually reaches the collecting duct The collecting duct takes waste down the area of the kidney called the pyramid where it collects all the waste from all the nephrons Then it follows out of the kidney in the urethra down the bladder where it's stored until the person gets that urge You know the urge when you need to go and then it's released out of the urethra That feels better. So the question is how many litres of blood have your kidneys filtered during the course of this video? Press pause now to give yourself time to work it out Did you get it right? The answer is Right all this talk of urinating and now I've got the urge. Oh well. See you later