1. Urinary System Edison D. Ramos, RMT, MPH Assistant Professor II College of Medical Technology Manila Central University

5. Urine Formation by Nephron Blood pressure forces water, glucose, amino acids and urea from capillaries into nephron Glucose and amino acids are reabsorbed into blood from nephron Some water is reabsorbed into blood Urine is urea and salt concentrated in water

6. Regulation of Water Balance Brain monitors water content of blood If low water content, pituitary releases ADH ADH travels in blood to nephron ADH causes more water to move from urine back into blood

7. Urinary System Has specific Performs specific Structure Function enables Kidney includes Nephron Collecting Ducts Minor Calyces Major Calyces Renal Pelvis Ureters Urinary Bladder Urethra Lead to Urine flows to Urine flows to Urine flows to Urine flows to Urine flows to Urine flows to Urine elimination includes Waste and foreign substance Urine storage Urine formation Tubular secretion Tubular reabsorption Glomerular filtration by

8. FUNCTIONS OF THE URINARY SYSTEM 1. Excretion - Kidney filter large amounts of fluid from the bloodstream. They are the major excretory organ because they eliminate nitrogenous wastes, drugs and toxin from the body. It also reabsorb needed substances and return them to blood. 2. Maintain blood volume and concentration - Regulating the proper balance in the blood between salt and water, regulate concentration of ions in body fluids and blood so the proper balance of Na, K, Ca, and phosphate ions is maintained. 3. pH regulation - Control the proper balance of hydrogen ions in the blood 4. Blood pressure - Produce enzyme RENIN which helps maintain blood pressure

9. 5. Erythrocyte concentration - Produce the protein hormone ERYTHROPOIETIN which stimulates red blood cell production 6. Vitamin D production - It converts vitamin D to calciferol which is its active form. Kidney participate along with liver and skin in vitamin D synthesis.

12. CORTEX – outer area of kidney MEDULLA – inner area of kidney RENAL PYRAMID – striated, triangular structure within the medulla whose bases face the cortex and tips point to the center of kidney (renal papillae) RENAL COLUMN – cortical material that extends between the pyramids MINOR CALYX – funnel-shaped structures that surround the tip of renal pyramid MAJOR CALYX – union of minor calyces RENAL PELVIS – union of major calyces, large collecting funnel which narrows to form ureter

14. ANATOMY OF THE NEPHRON NEPHRON – functional unit of kidney

15. BOWMAN’S CAPSULE – double-walled globe where nephron begins. GLOMERULUS – capillary network surrounded by bowman’s capsule PROXIMAL CONVOLUTED TUBULE – first part of the renal tubule DESCENDING LIMB OF HENLE – name given to PCT as it dips into the medulla LOOP OF HENLE – U-shaped structure of the limb of Henle ASCENDING LIMB OF HENLE – name given to loop of Henle as it ascends toward the cortex DISTAL CONVOLUTED TUBULE – name given to the ascending limb of Henle as it enters the cortex and becomes convoluted COLLECTING DUCT – connects with the distal tubules of the other nephron

20. Collecting Duct Allows for the osmotic reabsorption of water. ADH (antidiuretic hormone)- makes collecting ducts more permeable to water-- produce concentrated urine

24. 2. TUBULAR REABSORPTION - transport substances out of the tubular fluid and back into the blood of the peritubular capillary. Majority of the reabsorption occurs in the PCT. Active transport reabsorbs glucose and osmosis reabsorbs water. Positively charged ions are reabsorbed by active transport and negatively charged ions are reabsorbed by electrochemical attraction 3. TUBULAR SECRETION - moves the substances from plasma in the peritubular capillary into the fluid of the renal tubule PCT: secretes penicillin, creatinine and histamine RENAL TUBULE: secretes hydrogen ions DCT, COLLECTING DUCT – secrete potassium ions

28. PROBLEMS OF THE URINARY TRACT Incontinence (urine leakage) Causes of Incontinence Stress incontinence: leaking small amounts of urine when coughing, lifting, or exercising Urge incontinence: the bladder suddenly and unexpectedly contracts and expels urine Overflow incontinence: bladder cannot completely empty so urine dribbles

36. The End