1. The Urinary System

2. Function 1.Remove nitrogenous wastes 2.Maintain electrolyte, acid-base, and fluid balance of blood 3.Homeostatic organ 4.Acts as blood filter 5.Release hormones: calcitriol & erythropoietin

3. Kidneys as Filters Diuretic- loose water; coffee, alcohol Antidiuretic- retain water; ADH Aldosterone- sodium & water reabsorption, and K + excretion GFR= 180 liters (50 gal) of blood/day 178-179 liters are reabsorbed back into blood Excrete a protein free filtrate

5. Maintaining Chemical Homeostasis The Urinary System

7. urine blood filtration tubular reabsorption and secretion General Functioning of the Kidney “refreshed” blood

8. Nitrogenous Wastes ammonia urea uric acid

9. Organs of the Urinary System kidneys ureters urinary bladder urethra

10. renal capsule renal cortex renal medulla renal pelvis renal pyramids ureter Kidney Anatomy

11. renal artery renal vein nephron

12. urine blood filtration tubular reabsorption and secretion Nephron Functioning “refreshed” blood

13. Composition of Glomerular Filtrate WaterWater Small Soluble Organic MoleculesSmall Soluble Organic Molecules Mineral IonsMineral Ions

14. From the original 1800 g NaCl, only 10 g appears in the urine Urine Water- 95% Nitrogenous waste: urea uric acid creatinine Ions: sodium potassium sulfate phosphate

15. Hormonal Control of Kidney Function

16. Urinary Bladder ureters internal sphincters external sphincters urethra

17. Bladder 1.Mucosa (transitional epithelium) 2.Muscular layer (detrusor muscle): 3 layers of smooth muscle 3.Fibrous adventia

18. Internal urethral sphincter: Smooth muscle Involuntary control More superiorly located External Urethral sphincter: Skeletal muscle Voluntary control Posteriorly located Sphincter Muscles on Bladder

19. When bladder fills with 200 ml of urine, stretch receptors transmit impulses to the CNS and produce a reflex contraction of the bladder (PNS) Diuresis (Micturition) When is incontinence normal?

20. Why do doctors ask for a urine sample? Urinalysis characteristics: smell- ammonia-like pH- 4.5-8, ave 6.0 specific gravity– more than 1.0; ~1.001- 1.003 color- affected by what we eat: salty foods, vitamins

21. pH- range 4.5-8 ave 6.0 vegetarian diet- urine is alkaline protein rich and wheat diet- urine is acidic

22. Color- pigment is urochrome Yellow color due to metabolic breakdown of hemoglobin (by bile or bile pigments) Beets or rhubarb- might give a urine pink or smoky color Vitamins- vitamin C- bright yellow Infection- cloudy Color

23. Glucose- when present in urine condition called glycosuria (nonpathological) [glucose not normally found in urine] Indicative of: Excessive carbohydrate intake Stress Diabetes mellitus Abnormal Constitutes of Urine

24. Albumin-abnormal in urine; it’s a very large molecule, too large to pass through glomerular membrane > abnormal increase in permeability of membrane Albuminuria- nonpathological conditions- excessive exertion, pregnancy, overabundant protein intake-- leads to physiologic albuminuria Pathological condition- kidney trauma due to blows, heavy metals, bacterial toxin Abnormal Constitutes of Urine

25. Ketone bodies- normal in urine but in small amts Ketonuria- find during starvation, using fat stores Ketonuria is couples w/a finding of glycosuria-- which is usually diagnosed as diabetes mellitus RBC-hematuria Hemoglobin- Hemoglobinuria- due to fragmentation or hemolysis of RBC; conditions: hemolytic anemia, transfusion reaction, burns or renal disease Abnormal Constitutes of Urine

26. Bile pigments- Bilirubinuria (bile pigment in urine)- liver pathology such as hepatitis or cirrhosis WBC- Pyuria- urinary tract infection; indicates inflammation of urinary tract Casts- hardened cell fragments, cylindrical, flushed out of urinary tract WBC casts- pyelonephritus RBC casts- glomerulonephritus Fatty casts- renal damage Abnormal Constitutes of Urine

27. INQUIRY 1.List several functions of the kidneys. 2.What does the glomerulus do? 3.What are several constitutes you should not find in urine? 4.What is specific gravity? 5.What two hormones effect fluid volume and sodium concentration in the urine? 6. Where are the pyramids located in the kidney? 7.What vessel directs blood into the glomerulus? 8.Where does most selective reabsorption occur in the nephron?