1. Josephine Ebejer Grech

2. The Kidneys Your kidneys are two bean- shaped organs, each about the size of your fist. They are located in the middle of your back, just below your rib cage, on either side of your spine.

3. Josephine Ebejer Grech Your kidneys weigh about 0.5 percent of your total body weight. Although the kidneys are small organs by weight, they receive a huge amount - 20 percent - of the blood pumped by the heart. The Kidneys

4. Josephine Ebejer Grech cortex medulla pyramid pelvis Renal artery ureter

5. Josephine Ebejer Grech Renal vein The large blood supply to your kidneys enables them to do the following tasks:

6. Josephine Ebejer Grech The Kidneys Regulate the composition of your blood keep the concentrations of various ions and other important substances constant keep the volume of water in your body constant remove wastes from your body (urea, ammonia, drugs, toxic substances) keep the acid/base concentration of your blood constant Help regulate your blood pressure Stimulate the making of red blood cellsred blood cells Maintain your body's calcium levels

7. Josephine Ebejer Grech The human kidneys: are two bean-shaped organs, one on each side of the backbone. receive 20–25% of the total arterial blood pumped by the heart Each contains from one to two million nephrons.

8. Josephine Ebejer Grech The Nephron The nephron is a tube; closed at one end, open at the other. It consists of a:

9. Josephine Ebejer Grech The Nephron Bowman's capsule. Located at the closed end

10. Josephine Ebejer Grech The Nephron Glomerulus. A capillary network within the Bowman's capsule.

11. Josephine Ebejer Grech The Nephron Proximal convoluted tubule. Coiled and lined with cells carpeted with microvilli and stuffed with mitochondria.

12. Josephine Ebejer Grech The Nephron Loop of Henle. It makes a hairpin turn and returns to the

13. Josephine Ebejer Grech The Nephron Distal convoluted tubule, which is also highly coiled and surrounded by capillaries.

14. Josephine Ebejer Grech The Nephron Collecting tubule. It leads to the pelvis of the kidney from where urine flows to the bladder and, periodically, on to the outside world.

15. Josephine Ebejer Grech