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Flashcards in Exam 3 Renal Deck (53)
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1

ROLE OF THE KIDNEY

  • Balance solute and water
  • Help control blood pressure
  • Cleansing (filtering) of extracellular fluid (ECF) and maintenance
  • of ECF volume and composition
  • Excrete metabolic water-soluble wastes & foreign substances
  • Convert nutrients 
  • Regulates acid/base
  • Secretes renin and erythropoietin
  • Help maintain red blood cell levels
  • Converts vitamin D
  • Calcifediol to calcitriol, the active form

2

NEPHRONS

  • Nephrons are the functional unit of the kidney
    • Renal corpuscle (Glomerulus + Bowman capsule)
    • Proximal convoluted tubule
    • Loop of Henle
    • Distal convoluted tubule
    • Collecting duct 
  • All the components of the nephrons contribute to URINE formation 

3

GLOMERULAR FILTRATION RATE

(GFR)

  • Filtration rate of plasma per unit per time
  • 125 mL/minute
  • Prostaglandins increases GFR
  • Epinephinre and Endothelin decreases GFR
  •  

4

HOW DO KIDNEYS AFFECT

BP

Blood Pressure

  • Juxtaglomerular cells measure blood flow in the afferent arteriole and urine flow and composition.
  • Release renin, to Angiotensin II to aldosterone (RAAS)
  • Turns on Na/K ATPase
  • Increases BP
  • Vasoconstriction/thirst
  • Does not change blood osmolarity
  • Na and H2O reabsorbed
  • Lowers K

5

MICTURITION REFLEX

Micturition Reflex Begins when the bladder contains 150 to 250 mL of urine

Can be filled to ~500 ml, but pressure of detrusor muscle will overcome external sphincter

Bladder fills with urine  stretch receptors  sacral spinal cord stimulated  Spinal reflex stimulated

Babies

6

HYDROURETER

Dilation of the ureter

7

HYDRONEPHROSIS

Expansion of the kidney with urine

  • Increased pressure inside the renal capsule
  • Compartment syndrome compresses blood vessels inside kidney; renal ischemia

8

URINARY STASIS

Urinary Retention

  • Risk of infection
  • Stones

9

POSTOBSTRUCTIVE DIURESIS

Polyuric state in which copious amounts of salt and water are eliminated after the relief of a urinary tract obstruction

10

CAUSES OF

KIDNEY STONES

  • Masses of crystals, protein or other substances that are a common cause of urinary tract infections

Saturation theory: Urine is supersaturated with stone components. Influenced by pH and temperature 

  • Alkaline urine > chance of Ca+ stone formation
  • Acidic urine > of uric acid stone formation 

Matrix theory: Organic materials act as a nidus for stone formation 

Inhibitor theory: A deficiency of substances that inhibit stone formation

  • Unilaterally located in the kidneys, ureters, bladder
  • Renal tubules have many surfaces which attract a stone
  • Stones < 5mm have a 50% chance of spontaneous passage

Risk factors: 

  • Race
  • Age 
  • Gender
  • Geographic location& seasonal factors 
  • Fluid intake
  • Occupation

11

SIGNS & SYMPTOMS OF 

KIDNEY STONES

 

Flank pain (moderate to severe), may radiate to groin 

If stone is obstructing, pt may experience urgency, frequent voiding

May or may not have hematuria 

12

TREATMENT OF

KIDNEY STONES

  • Imaging needed to determine location of stone, severity of obstruction, size of stone
  • Obtain a UA to determine pH of urine 
  • STRAIN urine to retrieve stone for further analysis 
  • Pain management 
  • Dietary modification PRN
  • Nephrolithotomy or lithotripsy to remove stones

13

Benign Prostatic Hyperplasia

(BPH)

  • Non-malignant prostate enlargement due to excessive epithelial cell growth

14

SIGNS and SYMPTOMS

Benign Prostatic Hyperplasia 

(BPH)

S&S

  • Urinary hesitancy
  • Dysuria
  • Straining to void
  • Postvoid dribbling
  • Frequent daytime voiding 
  • Nocturia 
  • Poor force of stream 
  • Intermittent stream
  • Feelings of incomplete emptying

15

TREATMENT

Benign Prostatic Hyperplasia 

(BPH)

  • Invasive treatment
  • Transurethral resection of the prostate (TURP) 

Drug therapy 

  • 5-Alpha Reductase Inhibitors
  • Alpha1-Adrenergic Receptors 
  • Ie. Finasteride (Proscar)

    Reduces prostate size, takes several months

    MOA. Inhibits 5-alpha reductase enzyme that converts testosterone to dihydrotestosterone (DHT)

    SE. decreased ejaculate, toxic to male fetus

  • Ie. Doxazosin (Cardura), Tamsulosin (Flomax)

    MOA. Blockade of alpha1 receptors, relaxes smooth muscle in bladder neck, decreasing obstruction of urethra

    SE. Hypotension, fainting, dizziness 

 

16

URGE INCONTINENCE

(DETRUSOR OVERACTIVITY)

Common Causes:

  • Stroke
  • Alzheimer's disease
  • Parkinson's disase
  • BPH with overflow

Common Symptoms:

  • Urgency and frequency, day or night

Pharmacological Treatment

  • Anticholingergic drugs
  • Oxybutynin
  • Tolterodine

17

STRESS INCONTINENCE

(OUTLET INCOMPETENCE)

Common Causes:

  • Urologic procedures
  • history of multiple childbirths

Common Symptoms:

  • small volumes of urnie loss with coughing, sneezing

Pharmacological Treatment:

  • Alpha agonists
  • Topical estrogen

 

18

MIXED UI and SI

Common Causes:

See UI and SI

 

Common Symptoms:

 

Pharmacological Treatment:

19

OVERFLOW  INCONTINENCE

Common Causes:

  • BPH
  • Fecal impaction

Common Symptoms:

  • Poor stream
  • Incomplete emptying

Pharmacological Treatment:

  • Alpha-adrenergic blockers (e.g., terazosin and tamsulosin)

20

ATONIC BLADDER

Common Causes:

  • Severe diabetic neuropathy, stroke

Common Symptoms:

  • Complete loss of bladder control

Pharmacological Treatment:

  • Intermittent catherizations

21

FUNCTIONAL  INCONTINENCE

Common Causes:

  • Inability to get to the bathroom
  • Change in mental status

Common Symptoms:

  • Symptoms will vary

Pharmacological Treatment:

  • Eliminate causes

22

NOCTURNAL ENURESIS

  • involuntary urination that happens at night while sleeping, after the age when a person should be able to control his or her bladder.

23

NEUROGENIC BLADDER

UNINHIBITED BLADDER

(loss of bladder sensation)

Uninhibited bladder: reduced awareness of bladder fullness and a low capacity bladder; urinary incontinence

24

NEUROGENIC BLADDER

SPASTIC (HYPERTONIC)

  • Spastic (hypertonic): volume is typically small, pressures increase and involuntary contractions occur; increased frequency, urine leakage
  • Lesions between the pontine micturition center and sacral spinal cord
  • Bladder contraction and external urinary sphincter relaxation are typically uncoordinated (detrusor-sphincter dyssynergia)

25

NEUROGENIC BLADDER

FLACID (HYPERTONIC)

  • Flaccid (hypotonic): volume is large, pressure is low, and contractions are absent; overflow incontinence
  • Lesions from the sacral cord or sacral nerve root injuries

26

DETRUSOR

(BLADDER WALL)

HYPERTROPHY

Obstructions

27

OVERACTIVE BLADDER

(OA)

4 symptoms:

  • Urinary urgency                   
  • Urinary frequency
  • Nocturia
  • Urge incontinence

***Usually the result of involuntary contraction of the bladder***

28

TREATMENT OF

OVERACTIVE BLADDER

Behavioral 

  • Schedule voiding, time fluid intake, Kegel exercises, avoid caffeine 

Drug 

  • Anticholinergic agents which block muscarinic receptors
  • Ie. Oxybutynin (Ditropan)
  • These drugs block muscarinic receptors not only in the bladder but elsewhere…a way around this is using drugs that are selective for muscarinic receptors in the bladder (M3 receptors)
  • Even so they have a high SE profile of anticholinergic activity causing constipation (from reducing bowel motility), blurred vision and photophobia (from preventing contraction of the ciliary muscle)

29

UTI

URINARY TRACT INFECTIONS

 

Bacteria usually enter through the urethra

Host defenses include:

  • Washout phenomenon
  • Protective mucin layer
  • Local immune responses and IgA
  • Phagocytic blood cells
  • Normal bacterial flora and prostate secretions

Inflammation of urinary epithelium from bacteria

Can occur in the urethra (urethritis), prostate (prostatitis), bladder (cystitis), ureter, kidney (pyelonephritis)

Subtypes: complicated and uncomplicated; upper or lower 

Risks:

  • Premature newborns
  • Sexually active and pregnant women
  • Spermicide users
  • Individuals with indwelling catheters 
  • DM patients
  • Neurogenic bladder patients

30

ORGANISMS THAT

CAUSE UTI

Factors:Community associated 

E.coli (80%)

Hospital associated 

Klebsiella, Enterobacter, Proteus 

Catheter-associated urinary tract infection (CAUTI)