Anatomy and physiology 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. A Kidney Blood and waste enter through renal artery Filtered blood leaves through renal vein Excess water and toxic waste leaves through ureter as urine
- 7. General Functioning of the Kidney
- 8. Nitrogenous Wastes Proteins Amino acids COOH -NH2 Ammonia Urea Uric Acid
- 9. ureter Kidney Anatomy renal cortex renal pelvisrenal medulla renal pyramids renal capsule nephron
- 10. renal cortex renal medulla Each kidney contains over 1 million nephrons and thousands of collecting ducts Collecting duct Loop of Henle PCT DCTGlomerulus
- 11. Glomerulus To renal pelvis Peritubular capillaries Collecting duct PCT Loop of Henle DCT
- 12. Glomerular Filtration afferent arteriole glomerulus efferent arteriole Bowman’s capsule Filters blood; proteins can’t pass through
- 13. Composition of Glomerular Filtrate • Water • Small Soluble Organic Molecules • Mineral Ions
- 14. Proximal Convoluted Tubule Reabsorbs: water, glucose, amino acids, and sodium. • 65% of Na+ is reabsorbed • 65% of H2O is reabsorbed • 90% of filtered bicarbonate (HCO3 -) • 50% of Cl- and K+
- 15. Loop of Henle Creates a gradient of increasing sodium ion concentration towards the end of the loop within the interstitial fluid of the renal pyramid. • 25% Na+ is reabsorbed in the loop • 15% water is reabsorbed in the loop • 40% K is reabsorbed in the loop
- 16. Distal Convoluted Tubule Under the influence of the hormone aldosterone, reabsorbs sodium and secretes potassium. Also regulates pH by secreting hydrogen ion when pH of the plasma is low. • only 10% of the filtered NaCl and 20% of water remains
- 17. Collecting Duct Allows for the osmotic reabsorption of water. ADH (antidiuretic hormone)- makes collecting ducts more permeable to water-- produce concentrated urine
- 18. 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
- 19. Urinary Bladder ureters internal sphincters external sphincters urethra
- 20. 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?
- 21. 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; ~1.001-1.030 • color- affected by what we eat: salty foods, vitamins
- 22. odor- normal is ammonia-like diabetes mellitus- smells fruity or acetone like due to elevated ketone levels diabetes insupidus- yucky asparagus--- Odor
- 23. 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
- 24. Water: s.g. = 1g/liter; Urine: s.g. ~ 1.001 to 1.030 Specific Gravity When urine has high s.g.; form kidney stones Diabetes insipidus- urine has low s.g.; drinks excessive water; injury or tumor in pituitary
- 25. pH- range 4.5-8 ave 6.0 vegetarian diet- urine is alkaline protein rich and wheat diet- urine is acidic
- 26. Normal Constitutes of Urine
- 27. Normal Constitutes of Urine
- 28. Glucose Indicative of: • Excessive carbohydrate intake • Stress • Diabetes mellitus Abnormal Constitutes of Urine
- 29. Albumin Abnormal Constitutes of Urine
- 30. • Ketone • RBC • Hemoglobin • Bile • WBC • Casts Abnormal Constitutes of Urine
- 31. 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?
- 32. Moment of Zen