Di Sole 1

Question 1

general functions of the kidney

Answer 1

every 30 mins the kidneys filter the entire blood supply

• Excretion of metabolic waste products and foreign substances
• regulation of body fluids and electrolytes balance, acid-base balance and arterial blood pressure
• elaboration of endocrine hormones (erythropoietin, active vit D)
• Gluconeogenesis (during long fast)

Question 2

Glomerular capillary membrane layers

Answer 2

Layers make up the FILTRATION BARRIER

• endothelium of the capillary
• a basement membrane
• a layer of epithelial cell (podocytes)

High filtration rate across the glomerular capillary is supported by:

• perforation of the endothelium (fenestrae)
• meshwork o the basement membrane
• the long foot-like processes of the podocytes

Question 3

cortical nephrone vs juxtamedullary ephrone

Answer 3

• Cortical nephrone
  
  • neprhons that have glomeruli located in the outer cortex and SHORT loop of henle
  • surrounded by extensive network of PERITUBULAR CAPILLARIES
    
    • allows flexibility in regulation
• Juxtamedullary nephrones
  
  • nephrones that have glomeruli located deep in the cortex and LONG loop of henle (20-30% of nephrons)
  • SPECIALIZED peritubular capillaries (VASA RECTA)
    
    • specialized network of capillaries essential for formation of CONCENTRATED URINE

Question 4

Kidney processes: basic steps in urine formation

Answer 4

1. flomerular filtration
2. re-absorption of subatances from renal tubules into the blood
3. secretion of substances from the blood into the renal tubules
4. urinary excretion

EXRETION = FILTRATION - REABSORPTIONS + SECRETION

Question 5

Glomerular filtration rate (GFR)

Answer 5

• deteremined by the net filtration pressure and glomerular capillary filtration fraction coefficient
• Net filtration pressure is deteremined by the SUM OF:
  
  • Hydrostatic forces across the glomerular membrane
    
    • FORCE EXERTED BY FLUID AGAINST CAPILLARY WALL
  • Colloid osmotic forces across the glomerular membrane
    
    • PRESSURE EXERTED BY PROTEINS IN THE PLASMA
    • pressure required to prevent the solvent migration across a semipermeable membrane via osmosis

Question 6

what are the effect of changes in resistance on glomerular filtration rate (GFR)

Answer 6

• VASOCONSTRICTION of AFFERENT arteriole –> DECREASED GFR
• VASOCONSTRICTION of EFFERENT arteriole –> INCREASED GFR
• VASODILATION of EFFERENT arteriole –> DECREASED GFR
• VASODILATION of AFFERENT arteriole –> INCREASED GFR

Question 7

Stuff about filtration etc. Make notecards