1 / 45

Urinary System

Urinary System. Ch 26. Function. Remove nitrogenous wastes Maintain electrolyte, acid-base, and fluid balance of blood Homeostatic organ Acts as blood filter Release hormones: calcitriol & erythropoietin. Kidneys as Filters. Diuretic- lose water; coffee, alcohol

zahir-vasquez
Download Presentation

Urinary System

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Urinary System Ch 26

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

  3. Kidneys as Filters • Diuretic- lose 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

  4. Each kidney contains over 1 million nephrons and thousands of collecting ducts renal cortex renal medulla DCT Glomerulus PCT Collecting duct Loop of Henle

  5. Nephron’s functions: • glomerular filtration • tubular reabsorption • tubular secretion

  6. Histology of a renal corpuscle

  7. Pressures that drive glomerular filtration

  8. The filtration membrane

  9. Nephron

  10. Composition of Glomerular Filtrate • Water • Small Soluble Organic Molecules • Mineral Ions

  11. 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+

  12. 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

  13. 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

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

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

  16. urea Nitrogenous Wastes uric acid ammonia

  17. Hormonal Control of Kidney Function ADH ANP Renin-Aldosterone-Angiotensin

  18. Fig. 18.09 ADH

  19. posterior pituitary antidiuretic hormone collecting ducts Hormonal Control of Kidney Function hypothalamus

  20. ANP aldosterone

  21. Regulation of Aldosterone secretion by renin-angiotensin-aldosterone (RAA) pathway Fig. 18.16

  22. juxtaglomerular apparatus renin Hormonal Control of Kidney Function reduced blood pressure and glomerular filtrate

  23. angiotensinogen angiotensin I angiotensin II Hormonal Control of Kidney Function renin

  24. adrenal cortex aldosterone convoluted tubules Hormonal Control of Kidney Function angiotensin II

  25. ureters internal sphincters external sphincters urethra Urinary Bladder

  26. Bladder • Mucosa (transitional epithelium) • Muscular layer (detrusor muscle): 3 layers of smooth muscle • Fibrous adventia

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

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

  29. Urinalysis Why do doctors ask for a urine sample?        • 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

  30. Odor odor- normal is ammonia-like diabetes mellitus- smells fruity or acetone like due to elevated ketone levels diabetes insipidus- yucky asparagus---

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

  32. Color 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

  33. Specific Gravity Water: s.g. = 1g/liter; Urine: s.g. ~ 1.001 to 1.030 Pyelonephritus- urine has high s.g.; form kidney stones Diabetes insipidus- urine has low s.g.; drinks excessive water; injury or tumor in pituitary

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

  35. Abnormal Constitutes of Urine 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, bacterialtoxin

  36. Abnormal Constitutes of Urine 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

  37. Abnormal Constitutes of Urine 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

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

  39. Moment of Zen KIDNEY

More Related