URINARY SYSTEM AND HOMEOSTASIS

1. URINARY SYSTEM AND HOMEOSTASIS Dr.dr.Zaenal M. Sofro, AIFM, Sport & Circ. Med. Bagian Ilmu Faal Fak.Kedokteran UGM

5. Stimulates fluid absorption Enhances taste Promotes fluid balance Helps body to “hold” onto water Avoid Hyponatremia Maintains desire to drink NaCl

6. Muscle Motor Neuron Muscle Fibres Muscle Physiology Motor Unit

8. Homeostasis • The urinary system maintains homeostasis in several ways: • Removal of urea (nitrogenous waste) from the bloodstream. • Control of water and salt balance in the bloodstream. • Involved in blood pressure regulation.

9. Bayi yang baru Lahir Perempuan dewasa Laki-laki dewasa

10. ICF ISF plasma organs external environment internal environment Exchange and communication are key concepts for understanding physiological homeostasis.

11. Body Fluid Compartments: ICF: 55%~75% • Male (60%) > female (50%) • Most concentrated in skeletal muscle • TBW=0.6xBW • ICF=0.4xBW • ECF=0.2xBW 2/3 X 50~70% lean body weight TBW Extravascular Interstitial fluid 3/4 1/3 ECF Intravascular plasma 1/4

13. Internal Structure of the Kidney Renal Lobe Renal pyramids Renal papilla Renal Columns

14. Kidney - Internal Micro Anatomy • Nephron – the functional unit of kidney • Three physiological processes: 1) filtration, 2) reabsorption , and 3) secretion • These three processes cooperate to achieve the various functions of the kidney • Different sites  different primary functions

15. Renin • Renin is an enzyme released by the kidneys in response to a drop in blood pressure. • Renin catalyzes the production of angiotensin, a hormone that causes arterioles to constrict, raising blood pressure. This also causes water retention. How does this maintain homeostasis of blood pressure?

16. Renal Corpuscle and Filtration

17. % 120 100 80 General Level of Physiologic Function 50 40 20 Active Person Age, year Sedentary Person

18. Erythropoietin • A second response to low blood pressure is the release of erythropoietin, another hormone. • Erythropoietin travels to the bone marrow and stimulates the production of new blood cells. How does this maintain homeostasis?

19. Proximal tubule • Nutrients (salts, vitamins, etc.) are moved out of the tubule through active transport. • Water follows the nutrients by osmosis.

20. Nephron-Tubular System • Proximal convoluted tubule • Descending loop of Henle • Ascending loop of Henle • Distal convoluted tubule • Collecting duct

21. Loop of Henle • Tissue around the Loop of Henle is salty, from active transport and diffusion of sodium chloride. • The salty conditions allow water to diffuse out of the loop.

22. Distal tubule • Active transport is used to move more nutrients out of the concentrated urine. • Some ions, drugs, and toxins are actively pumped into the tubule.

23. Collecting Duct • More water leaves the tube by osmosis, since the tube is surrounded by salty tissue. • Some urea leaves by diffusion, and may be cycled through the system.

26. Extremely Dehydrated Drink Water Immediately Mildly Dehidrated Drink More Water Safe Zone Not Dehydrated

27. Figure 25.5

28. urine flow drink 1200 ml water drink 1200 ml isotonic saline osmolarity osmolarity urine flow PENGARUH JENIS MINUMAN TERHADAP OSMOLARITAS TUBUH Two Very Different Experimental Observations

30. Thirst

31. Second Level Brain Stem Third Level First Level

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