Kidneys by Uchenna

  1. The Nephron
    • 1 million cells each kidney
    • Consists of glomerulus and tubules

    • 2 types
    • Juxtamedullary
    • (15%)
    • Cortical
    • (85%)

    *know where drugs work and how dysfunction of each area manifests
  2. The Glomerulus
    • Consists of compact tuft of capillaries – Bowman’s capsule
    • Fluid and particles filtered into Bowman’s space
  3. Tubular Components of NEPHRON
    • 4 segments
    • Proximal convoluted tubule
    • Loop of Henle Distal
    • Convoluted tubule
    • Collecting tubule
  4. Glomerular Filtration
    • Begins with filtration of fluid into Bowman’s space
    • Chemical composition similar to plasma, except almost no proteins – cannot pass through glomerular wall
    • Approx 125ml filtrate formed each minute (Glomerular filtration rate = GFR) Protouria is issue with filtration
    • High pressure system (60mmHg)
    • Innervated by Sympathetic nervous system, renin-angiotensin-aldosterone system
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  6. Tubular Reabsorption and Secretion
    • Nearly all of Glomerular filtrate reaborbed in normal circumstances
    • Water and urea passively absorbed
    • Sodium, potassium, chloride, calcium, phosphate ions, glucose, amino acids are actively transported across cell membranes
  7. Tubular Reabsorption and Secretion
    • Proximal tubule – 65% of all reabsorption along with nutrients (ex. Glucose)
    • Loop of Henle – concentration of urine- reabsorbs more NA and CL than water Distal and collecting tubules – reabsorbs sodium and chloride, impermeable to water – dilutes tubular fluid
  8. Regulation of Urine Concentration
    ADH effects kidney to concentrate or dilute urine to respond to changes in osmolality of ECFADH controls permeability of tubules
  9. Regulation of Blood Flow
    • Kidneys filter 1000ml – 1300ml blood/minute and receive 20% - 25% of cardiac output
    • Neural and Humoral Control
    • Dopamine
    • Angiotensin II
    • ADH
    • Autoregulatory
    • Blood flow varies based on arterial pressure
    • Juxtaglomerular Complex
    • Plays feedback role in release of renin
  10. Elimination Functions of the Kidney Slide 2
  11. Uric Acid Elimination
    • Product of purine metabolism
    • Urea Elimination
    • End product of protein metabolism
    • Drug Elimination
  12. Elimination Functions of the Kidney Slide 1
    • Renal Clearance
    • Volume of plasma cleared each minute Every substance has its own clearance rate Ex: glucose normally should be zero
    • Regulation of Na+ and K+ elimination Regulated by GFR and humoral agents Regulation of pH Conserves base bicarbonate and eliminates H+ ions
  13. Uric Acid Elimination
    • Product of purine metabolism
    • Urea Elimination
    • End product of protein metabolism
    • Drug Elimination
  14. Endocrine Functions of the Kidney
    • Renin-Angiotensin-Aldosterone System
    • Renin synthesized in juxtaglomerular nephrons of kidneys

    • Erythropoetin
    • Most formed in kidneys
    • Responsible for RBC formation in bone marrow

    • Vitamin D
    • Activation occurs in kidneys
  15. Urine tests Tests of Renal Function
    • Single specimens
    • 24 hour collections

    • Glomerular Filtration Rate
    • Creatinine Clearance – 115 – 125ml/min

    • Blood Tests
    • Serum creatinine – 0.6 – 1.2mg/dl
    • BUN – 8 – 20 mg/dl
  16. Based on what you know, what would expect to be the normal values of each of the following in a urine sample?
    • Color
    • Clarity
    • Glucose
    • RBCs
    • WBCs
    • Protein
    • Ketones
  17. Agenesis and Hypoplasia
    • Congenital Disorders
    • Most of amniotic fluid is fetal urine – indicator of fetal kidney function
    • Simple and Acquired Renal Cysts
    • Medullary Cystic Disease
    • Cause of renal failure in up to 25% of children
  18. Polycystic Kidney Disease
    • Autosomal dominant disorder
    • Manifestations: pain as cysts enlarge, hematuria, UTI from infected cysts, HTN, may progress to ESRD
    • Dx: US, CT
    • Tx: control of sx, HTN, dialysis and renal transplant in ESRD cases
  19. Hydronephrosis
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    • Obstruction causes stasis of urine in kidney → renal calculi, infection, dilation of renal pelvis and eventual renal atrophy

    Manifestations: pain, s/s uti, s/s renal dysfunction
  20. Renal Calculi
    Crystalline materials of normally excreted by products in urine

    • Types of stones
    • Calcium – most common
    • Magnesium – often associated with infection
    • Aka: struvite stones
    • Uric acid – usually present in acidic urine
    • Cystine – rare

    • Manifestations: pain, nausea, vomiting
    • Dx: Xray, US, CT, IVP, urinalysis
    • Tx: pain relief, fluids, surgery, stone
  21. Urinary Tract Infections
    • Most pathogens enter via urethra
    • Can affect lower or upper urinary tract
    • Factors that predispose patients
    • Host defenses
    • Pathogen virulence
    • Obstruction
    • Reflux
    • Catheters
    • Manifestations: urgency, frequency, dysuria, pelvic or back pain, cloudy or foul smelling urine, fever
    • Dx: UA and urine c/s, US, CT
    • Tx: Antibiotics
  22. Pyelonephritis
    • Acute
    • Caused by infection
    • Chronic
    • Caused by infection or other problems such as reflux

    • Manifestations: abrupt onset of fever, malaise, chills, back pain, CVA tenderness, dysuria, frequency
    • Dx: UA, urine c/s
    • Tx: Antibiotics
  23. Nephritic Syndromes
    • hematuria with RBC casts, ↓ GFR, azotemia, oliguria, HTN
    • Caused by diseases that provke inflammatory responses in cells of glomeruli
    • 3 types
    • Acute Proliferative Glomerulonephritis
    • Usually caused by strep infection
    • Rapidly Progressive Glomerulonephritis
    • Numerous causes (Lupus, vasculitis, etc)
    • IgA Nephropathy
  24. Nephrotic Syndrome
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    • Problem that results in excessive loss of protein (>3.5g/24h) from increased glomerular permeability
    • Edema and hyperlipdemia characteristic
    • Can be acute or chronic in nature
  25. Drug-Related Nephropathies
    • Drugs can impair blood flow, damage nephrons, form crystals which cause obstruction or by producing hypersensitive reactions
    • Ex: sulfa drugs, PCNs, NSAIDs, ASA
  26. Chronic Glomerulonephritis
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    • Many causes
    • SLE – caused by deposits on immune-complexes in glomerular wall
    • Diabetes – elevations in glucose alter glomerular membrane and increase amount of protein in filtrate
    • Hypertension – causes sclerosis of renal arteries, reducing blood flow
  27. Wilms Tumor
    • most common primary neoplasm of young children
    • Dx: CT
    • Tx: Surgery, chemo, RTx
    • Adult Kidney Cancer
    • Dx: CT, MRI
    • Tx: Surgery, chemo
  28. Renal Failure
    • Kidneys not able to remove body’s metabolic wastes which disrupts fluid volume, electrolyte balance, acid-base balance
    • Two Types
    • Acute
    • Chronic
  29. Acute Renal Failure Phases
    • Phases
    • Onset
    • Maintenance
    • Recovery
    • Dx: urine tests, serum BUN, Cr
    • Tx: ID cause, avoidance of nephrotoxic substances, strict I&O, dialysis
  30. Chronic Renal Failure
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    • Develops when renal function < 25% of normal or when GFR <15ml/min
  31. Stages of CKD
    Edit and add ur own
  32. Treatments For Chronic Kidney failure
    • Dialysis
    • Hemodialysis
    • Peritoneal Dialysis
    • Renal Transplant
    • Dietary Management
  33. Nerve Control of Bladder Function
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  34. Urinary Obstruction and Stasis
    • Congenital: congenital narrowing of external meatus
    • o r
    • Acquired: BPH
    • Can cause urinary stasis → UTI, hydroneprosis, kidney damage
  35. Neurogenic Bladder Disorders
    Spastic Bladder - failure to store urine due to reflex bladder spasm with a decrease in bladder urine volume

    • Flaccid Bladder – atony of the bladder allowing for overfilling
    • Non-relaxing External Sphincter
  36. Urinary Incontinence
    • Stress Incontinence
    • Involuntary loss of urine associated with activities (ex. Coughing)
    • Urge / Overactive
    • Urgency and frequency associated with hyperactivity of the detrusor muscle
    • May or may not cause involuntary loss of urine
    • Overflow
    • Involuntary loss of urine when bladder pressure exceeds urethral pressure
  37. Urinary Incontinence
    • Dx: blood tests, urine tests, voiding diary, stress test, urodynamic studies
    • Tx: kegel exercises, toileting schedule, medications, surgery
  38. Catheter-Associated Urinary Tract Infections
    • Who is at risk for CAUTIs?
    • How can nurses reduce the risk of CAUTIs in patients undergoing urinary catheterization?
Card Set
Kidneys by Uchenna
Kidney and Urinary