3 functions of the urinary system

1. 3 functions of the urinary system • Excrete nitrogenous wastes • Urea produced from the metabolism of proteins and nucleic acids • Other animals produce ammonia or uric acid • Regulate water balance • Regulate salt balance

3. Filters the blood Produces urine (contains urea) Regulates water and salt balance

4. Transports urine from the kidney to the urinary bladder

5. Stores the urine. Has specialized expandable cells

6. Carries the urine to the outside of the body

9. Bowman’s capsule Proximal tubule Glomerulus Capillaries Artery Fig. 25-6d Artery Distal tubule From another nephron Branch of renal vein Collecting duct Loop of Henle with capillary network

10. Everything in the blood smaller than blood cells or large proteins is filtered into the nephron at the glomerulus/bowman’s capsule Salts are secreted into urine if their concentration in the blood is too high Vital materials -sugars -amino acids -water -NaCl Are reabsorbed into the blood, so they do not leave the body Urine is excreted from the body

11. Kidney tubule Kidney tubule 1 Bowman’s capsule H2O Nutrients H2O HCO3– NaCl HCO3– NaCl Blood K+ Some drugs and poisons H+ H+ 3 Fig. 25-8 Filtrate composition Collecting duct Cortex H2O NaCl HCO3– H+ Urea Glucose Amino acids Some drugs Medulla Loop of Henle 2 NaCl NaCl H2O Reabsorption Secretion Filtrate movement Urea NaCl H2O Urine (to renal pelvis)

13. Fig. 25-7 Filtration Reabsorption Secretion Excretion Nephron tubule Urine H2O, other small molecules Capillary Interstitial fluid