2. Functions of The Urinary System -Rid the body of Nitrogen Waste -Regulate water balance -Regulate electrolytes (ions) Ca+, K+, Na+ -Regulate acid/base -assist in blood pressure -stimulate RBC production

3. I.Kidney-- Location-dorsal lumbar region protection – rib cage size –5’’ x 2 ½” 1. Hilus—Indentation, blood vessels, nerves enter & exit 2. Adrenal gland- sits atop, endocrine system 3. Renal Capsule-encloses & maintains kidney position 4. Renal Cortex-outer region, contains Bowman’s Capsule 5. Renal Medulla---inner region,contains Medullary Pyramids (Loop of Henle) 6. Renal Pelvis—Basin cavity contains, tips of pyramids  ureter upper part--Calyx

4. II Blood Supply ¼ of blood is filtered per minute – 1.25 L/minute 7. Renal artery - blood supply to cortex tissue -- dirty 8. Renal vein –returns blood -- clean 9. Ureter – Function: carry urine from kidney to bladder via peristalsis valve flaps at junction to bladder 10. Urinary bladder- collapsible muscular sac 3 openings into that form trigone area (infections occur) In males– prostrate gland problems Function: stores urine 1 pint  2 pints 11.Urethra – carry urine outside of body via perstalsis internal sphincter—involuntary control external sphincter—voluntary control

5. Nephron: -functioning unit of the kidney, filters & produces urine upper section in the cortex lower section makes up the medullary pyramids 2 structures make up the nephron: 1. Glomerulus– knot of capillaries 2. Renal Tubule– collecting tube 1. Bowman’s Capsule: closed end of renal tubule that cups end encloses the glomerulus 2. Renal Tubule: made up of 3 areas 1. Proximal Convoluted Tubule (PCT) many villi 2. Loop of Henle 3. Distal Convoluted Tubule (DCT) 3. Collecting Tubule: receives urine from nephron, runs through pyramid & empties into pelvis

6. Urine Formation: 3 step process - filtration - reabsorption - secretion ~maintain balance of water and electrolytes & remove nitrogen 1. Filtration: -Occurs at Bowman’s Capsule -passive process of filtration due to blood pressure 2. Reabsorption: -Occurs at PCT *Primary Site* - active transport -reabsorb useful molecules aa Na + K + glucose (also occurs) Loop of Henle – reabsorption of water by passive diffusion ~urea and uric acid not reabsorbed 3. Secretion: -some substances pass back into tubule based on bodies electrolytes levels and pH -occurs at DCT

7. Nitrogen Waste 24 hr filter 150L-180L of blood = 1  1.8L urine produced Filtrate- mostly blood plasma filtered at the Bowman’s capsule Urine- remainder of filtrate that contains waste Nitrogen waste – 1.Urea- end product of protein (aa) breakdown ammonia +Co2 2.Uric acid- breakdown of nucleic acids (DNA+RNA) produced birds + reptile 3.Creatinine -by product of energy production in muscle

8. Water Balance H2O reabsorption is controlled by hormones Stimulate – pituitary Result – release ADH antidiuretic hormone Target tubule increased permeable to H2O = increased ADH Urine Characteristics * Fresh urine - clear  deep yellow yellow color- pigment urochrome - destroyed hemoglobin increase solutes – deep yellow is from concentrated urine up H2O – diluted pale urine Color affected by blood, beets First formed – sterile ammonia smell comes from bacteria pH ~6 affected by diet + disease

9. Abnormalities in Urine Glycosuria – glucose in urine Proteinuria – protein in urine Pyuria – WBC’s + bacteria in urine Hematuria – RBC’s in urine Disorders Hydronephrosis – kink in ureter - blocks kidneys Kidney stones – urine solutes, uric acid form crystals - few, small – no problem - lodged, pokes ureter walls - pain, irritation blood

10. Disorders Renal failure – any condition interferes with kidney function – Acute condition- extensive damage urea builds in blood – Complete failure – death in 1-2 weeks Glomerulonephritis – inflammation of filter membrane Glomerulus filter clogged with WBC’s +plasma proteins Urinary tract infection – inflammation of urethra, ureters, kidneys Painful urination Incontinence – loss of voluntary control of external urethral sphincter Dialysis – need when too many of nephrons are damaged artificial kidney