Patho ch30.txt

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Patho ch30.txt
2011-10-17 17:21:21

Mountain State University Physician Assistant Class of 2014 - Pathophysiology Ch 30
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  1. What is the difference between afferent and efferent arterioles?
    Afferent carry blood toward the nephron, efferent carry blood away
  2. Where are the kidneys located?
    Outside the peritoneal cavitiy in the back of the upper abdomen, level of t12-L3
  3. How much blood flow do the kidneys receive?
    About 22% of cardiac output
  4. What are the high and low pressure systems for in the nephron?
    • High for filtration
    • Low for reabsorbtion
  5. What happens if you increase resistance in the Afferent arterioles?
    Gfr decreases
  6. What happens when the Efferent arterioles constrict?
    Hydrostatic pressure increases so gfr increases but renal blood flow decreases so filtration fraction decreases
  7. Describe the proximal convoluted tubule
    • Highly coiled
    • Drains bowmans capsule
    • Rich in mitochondria
    • Regulates filtrate ph by exchanging H+ in interstitium for bicarb in filtrate
    • Site of origination for renal cell carcinoma
  8. What is symport?
    Transportation of different molecules or ions in the SAME direction by a common carrier
  9. What is antiport?
    Transportation of different ions in OPPOSITE directions
  10. What are the elimination functions of the kidney?
    • Renal clearance
    • Regulation of sodium
    • Pottasium elimination
    • pH dependent elimination of ions
    • Uric acid
    • Urea
    • Drugs
  11. Describe the juxtaglomerular complex
    • Juxtaglomerular cells are modified smooth muscle cells in afferent and sometes efferent that contain renin
    • Extraglomerular mesangium (lacis cells) phagocytic located in angle between afferent and efferent
    • Macula densa of DCT triggers renin release
    • Granular epithial peripolar cells at angle of parietal to viseral capsule at corpuscle controls ecf and gfr thru renin-angiotensin
  12. What is the definition of renal clearance?
    The volume of plasma that is completely cleared each minute of any substance in the urine
  13. What determines renal clearance?
    • Ability of the substance to be filtered by glomeruli
    • The capacity of the renal tubules to reabsorb or secrete the substance
  14. What are the characteristics of normal urine?
    • Clear to amber color
    • 95% water 5% dissolved solids
    • Normally 1.5L a day
    • Metabolic wastes and no proteins blood cells or glucose
  15. What are some tests for renal function?
    • Urinalysis
    • Gfr
    • Blood test - serum creatinine blood urea nitrogen
    • Cytoscopy
    • Ultrasonography
    • Radiologic and other imaging
  16. What happens during sympathetic stimulation of the kidneys?
    Blood flow is directed to the medulla to maintain urine concentrating to maintain blood volume such as in shock
  17. What are the two types of nephrons?
    Cortical (85%) and juxtamedullary (15%)
  18. The thin double walled capsule that surrounds the capillaries in the glomerulus
    Bowmans capsule
  19. Perforations in glomerular capillaries endothelial layer
  20. Structures in the epithelial layer that contain slit pores?
    Foot processes or podocytes
  21. What are the four segments of the nephron tubule?
    PCT, loop of henle, DCT, CT
  22. What are Mesengial cells?
    Support glomerulus cailleries where basment membrane and endothelium dont cover, secrete substance similar to basement membrane, may be involved in regulation of blood flow
  23. What are the two segments of the DCT?
    • The diluting sement
    • Late distal tubule
  24. What are the two segments of the collecting tubule?
    • Cortical collecting tubule
    • Inner medullary collecting tubule
  25. What layers do the tubules consist of?
    Single layer of epithelial cells resting on a basement membrane
  26. What can happen during sting sympathetic stimulation such as shock?
    Gfr and urine output can drop to zero
  27. 65% of all reabsorption and secretory processes occur where?
  28. What are the endocrine functions of the kidney?
    • Renin-angiotensin
    • Epo
    • Activation of vitamin D
  29. How do loop diuretics like lasix work?
    Reduce sodium and potassium reabsorbtion and increase calcium and magnesium elimination in the thick ascending loop of henle
  30. How do thiazide diuretics work?
    They prevent the reabsorbtion of sodium in the early DCT