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
Nephrotic Syndrome: 24 hour protein urine
Dx: 3-3.5g urine protein or greater
coupled with: < 2.5g/dL serum Albumin
Nephrotic Syndrome: dx
diagnosis of exclusion!!!!!!!!
- r/o secondary causes first
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
primary causes of nephrotic syndrome
minimal change ds** MC children
focal segmental glomerulsclerosis* MC adults
Membranous Glomerulonephritis
Mesangial Proliferative Glomerulonephritis
Rapidly Progressive Glomerulonephritis
nephrotic ds tx
1) treat inflammation first to heal kidney -> Corticosteroids:
- high dose corticosteroids/Prednisone
- based on height m^2 (100-120 mg/day to start)
- then taper
Immunosuppressive Agents:
- Indicated if Recurrent Nephrotic Syndrome or Non-Responsive
- drug name: cyclophosphamide
Treat underlying cause! (while on steroids)
nephrotic ds tx by complications
edema:
- lean protein diet
- limit water + salt intake
- loop diuretics
hypoalbuminemia: dietary protein
hyper coagulability: LMW heparin
hyperlipidemia: statins, diet
Nephritic Syndrome two types
Focal Proliferative
- Alport Syndrome
- SLE
- IgA Nephropathy
- Chronic Hepatic Failure
- Celiac
Diffuse Proliferative Membranoproliferative:
- Hep B/C
- SLE
- Sickle Cell Disease
Diffuse Proliferative : Rapidly Progressing Glomerulonephritis
Nephritic Syndrome MCC
Post-strep glomerulonephritis:
- pt has a sore throat and doesn’t get it fixed
Goodpasture’s Syndrome definition and presentation
Definition: Autoimmune disorder affecting Pulm & Renal
- Immune system insult → Anti-GBM antibodies → Attacks Glomerular Basement Membrane
Pt with lung and kidney damage: spitting out blood and peeing out blood
- Damages the basement membrane
- Suspicious: order antibody test
- Mortality: 100% with no tx
Goodpasture’s Syndrome sx
Hemoptysis
Hematuria/Proteinuria
Nephrotic OR Nephritic Syndrome
Malaise/Fever/Chills
Goodpasture’s Syndrome tx
Plasmapheresis
Immunosuppressive Agent
- Cyclophosphamide
- Prednisone
