intro Flashcards
Two Types of Nephrons
Juxtamedullary:
- Longer nephron with Loop of Henle extending into Kidney Medulla
- Primarily for urine concentration
- Reabsorbs higher proportion of filtrate
- HIGH use of energy
Cortical: SHORTER nephron with Loop of Henle extending into Kidney Cortex; less efficient
Filtration: must pass through what
Fenestrated Capillary Membrane
Glomerular Basement Membrane
Podocyte Foot Processes
countercurrent multiplier
Renal blood flow (RBF), glomerular capillary pressure (P_GC), glomerular filtration rate (GFR), filtration fraction (FF), and end-proximal fluid delivery define
Renal Blood Flow (RBF): volume of blood that passes through the kidneys per unit time
Glomerular Capillary Pressure (P_GC): BP within the capillaries of the glomeruli
GFR: rate at which blood is filtered through all the glomeruli in the kidneys
FF: ratio of the glomerular filtration rate (GFR) to the renal plasma flow (RPF) -> plasma component of RBF
End-proximal Fluid Delivery: volume of fluid that reaches the end of the proximal tubule in the nephron
Effects of afferent and efferent tone
functions of Kidneys:
Synthesis of Vitamin D
Secretion of EPO
- feedback loop, important in CKD
Cystatin C test
A protein whose level is related to renal function
↑ Cystatin C = ↓ Renal Function
new test!!
eGFR calculating factors
eGFR = (140-age) x Weight (kg)72 x Cr x .85 (female)
NO RACE in equation
Know age, weight, creatinine, gender affects it
- Age: kidney function worsens over years; lean body mass decreases with age
eGFR uses
- staging ds
- CKD: staging and planning
- medication management: if kidney not working -> adjust dose
- safety during procedures
KUB xray
not used often: Bowel gas in the way
evaluates kidneys, ureter, bladder
Ultrasound: use as diagnostic imaging
- fast, noninvasive, no radiation
- evaluate structure of kidney and bladder
- doppler US: evaluate renal blood flow
urinary pyelogram: use as diagnostic imaging
IV contrast is evaluated as it is excreted by kidneys
Used to assess functional urinary system
cystography: use as diagnostic imaging
- Contrast injected via urinary catheter into urinary system
- May evaluate vesicoureteral reflux
○ Incompetent valve allowing urine to flow backward -> could cause a major infection in the kidney (pyelonephritis)
CT w IV contrast: use as diagnostic imaging
STRUCTURAL eval of kidneys
Bumps in renal artery: RENAL ARTERY STENOSIS
risk:
- 1) adverse effect on kidney function
2) Extravasation = common
3) Allergic reactions
Ureteroscopy: use as diagnostic imaging
Endoscopic examination of Upper GU
- pass through urethra to bladder
nephrotic vs nephritic syndrome
Nephrotic:
- inflammation causes increased permeability and increased filtration
- EDEMA: facial and generalized
- proteinuria ; decrease protein in serum
- hyperlipidemia
- hypercoagulable state
Nephritic:
- BLOOD in urine: “coca cola urine”
- destruction of epithelial lining of glomerulus
- decreased renal perfusion causing increased BP
- oliguria
Minimal change disease
MCC of nephrotic syndrome in children!!!
Bx of nephron/glomerulus: under light microscopy looks normal
- need histology under electron microscope
- “loss of foot processes or effacements”
secondary causes of nephrotic syndrome
Focal Segmental Glomerulosclerosis
MCC of nephrotic syndrome in Adults
Microscopy = Tissue Scarring
- some glomeruli scarred while others spared
