2. URINARY SYSTEM

3.  To identify and describe the main organs of the urinary system  To describe the structure of a nephron.  To describe the 3 steps of urine formation in the nephron. OBJECTIVE

4. URINARY SYSTEM  All reactions in the body require watery surroundings in order to occur  That fluid must be closely regulated to ensure that the solution is not too salty or not salty enough  The urinary system helps to keep that balance.

5. SIMON SAYS

6. KIDNEY remove wastes from the blood, form urine

7. URETERS  transfer urine from the kidneys to the bladder

8. BLADDER  store urine until it is released by the body

9. URETHRA  carry urine from bladder to outside of the body

10. NEPHRON  The kidney is made up of repeating units called nephrons  These help maintain fluid balances

11. NEPHRON STRUCTURE

12. Glomerular capsule Proximal Convoluted Tubule (PCT) Distal Convoluted Tubule (DCT) Nephron Loop Collecting Duct Glomerulus

13.  Renal corpuscle NEPHRON STRUCTURE

14.  Take 2 minutes to study your nephron diagrams.  Be able to label  Renal corpuscle  Glomerulus  Glomerular capsule  Proximal Convoluted Tubule  Nephron Loop  Distal Convoluted Tubule  Collecting Duct NEPHRON STRUCTURE 2:001:591:581:571:561:551:541:531:521:511:501:491:481:471:461:451:441:431:421:411:401:391:381:371:361:351:341:331:321:311:301:291:281:271:261:251:241:231:221:211:201:191:181:171:161:151:141:131:121:111:101:091:081:071:061:051:041:031:021:011:000:590:580:570:560:550:540:530:520:510:500:490:480:470:460:450:440:430:420:410:400:390:380:370:360:350:340:330:320:310:300:290:280:270:260:250:240:230:220:210:200:190:180:170:160:150:140:130:120:110:100:090:080:070:060:050:040:030:020:01End

15. NEPHRON STRUCTURE

16.  Occurs in nephron  3 Steps  Filtration  Reabsorption  Secretion URINE FORMATION

17.  Movement of water and solutes from the capillaries into the glomerular capsule URINE FORMATION: FILTRATION What about blood?

18.  Glomerular filtration rate (GFR): total amount of water filtered per unit of time URINE FORMATION: FILTRATION

19.  Movement of useful substances (water, salts, glucose) back into the capillaries. URINE FORMATION: REABSORPTION

20.  Filtrate from glomerular capsule flows into the renal tubule.  Substances are reabsorbed into the surrounding capillaries. URINE FORMATION: REABSORPTION

21.  Sodium is actively pumped out of the epithelial cells of the renal tubule and diffuses into capillaries. URINE FORMATION: REABSORPTION

22.  The increased sodium in the interstitial space creates high osmotic pressure, which draws water out of the tubule by osmosis. URINE FORMATION: REABSORPTION

23.  At the same time that the “good” substances are being reabsorbed, wastes (urea) still in the blood are actively secreted from the capillaries. URINE FORMATION: SECRETION

24. URINE FORMATION

25. PRACTICE

26.  What causes sodium reabsorption? PRACTICE

27.  What causes water reabsorption? PRACTICE

28.  In which step of urine formation are waste substances put INTO the renal tubule? PRACTICE