Flashcards in Renal Therapeutics 3: Renal dysfunction, controlling incontinence Deck (19):
What are the three parts of the urinary tract and what are their functions?
1. Ureters (tube that connects kidney to bladder)
2. urinary bladder (stores the urine)
3. Urethra- the tube which allows the urine to exit
Describe the micturition reflex and how it co-ordinates the process of urination?
1. Sensory fibers in the pelvic nerve sense stretch due to the bladder filling
2. Parasympathetic fibers control muscle contraction
3. Interneurons communicate with hypothalamus via relays to the cortex
4. Voluntary relaxation of external sphincter results in urination as urethra widens
Explain how the contraction occurs down the walls of the bladder?
1. Bladder fills with urine
2. Stimulus travels down the pelvic nerves which stimulate ganglionic neurons in wall of bladder
3. Postganglionic neuron in intramural ganglion stimulates the detruscor muscle contraction
4. Interneuron relays sensation to thalamus and deliver sensation to cerebral cortex
5. Voluntary relaxation of external thus internal urethral sphincter
How does the micturition reflex differ in infants?
There is a lack of voluntary control over urination as the corticospinal connections are not established
How does the micturition reflex differ in age related changes in the urinary system?
1. Decline in number of functional nephrons
2. Reduced sensitivity to ADH
3. Problems with micturition reflex
What are micturition reflex problems that can occur?
1. Sphincter loses muscle tone which means incontinence
2. Control of the system lost due to:
- Alzheimers disease
- CNS problems that affect cerebral cortex or the hypothalamus
3. Urinary retention may develop if enlarged prostate gland compresses the urethra and restricts urine flow
What does urinary incontinence mean?
The involuntary loss of urine that is enough to cause a social or hygiene concern
What is stress incontinence and how is it caused?
1. Caused by coughing, sneezing, laughing or carrying heavy weights- normal control weakened
2. Urethra moves out of the normal position (prolapses)
- Weakening of level floor muscles
What is urge incontinence and how is it caused?
1. Strong urge to pass frequent and small amounts of urine
2. Caused by muscle of the bladder wall (detrusor muscle) being overactive or bladder infection (less urine produced)
3. Can mean it contracts to squeeze out urine before the bladder is completely full
4. Diabetes can cause excessive production of urine and frequent trips to toilet
What is overflow incontinence and how is it caused?
1. Urine held in the bladder builds up to the point where the bladder can no longer expand
2. Caused by obstruction in the urinary tract or damage to the nerves that supply the bladder
What other factors may cause incontinence?
1. Medication- side effects of some drugs for hypertension such as parson, doxazosin and muscle relaxants like diazepam
2. Urinary system problems like:
- Fistulas (abnormal opening between ureter, urethra or bladder into the uterus or vagina)
- Bladder stones
How do you treat stress incontinence with behavioural techniques
1. Scheduled toileting every 2 to 4 hours
2. Frequently emptying the bladder and keeping the patient dry- recommended for frail elderly or bed ridden patients
3. Pelvic floor exercises
4. Surgical treatments- usually successful
How do you treat incontinence with pharmacologic techniques?
1. Solifenacin succinate: first line of treatment
2. Tofranil (imipramine): similar effect on the bladder: 25mg nightly
1. Duloxetine: moderate to severe stress urinary incontinence
2. Antimuscarinic drugs reduce contractions of bladder and increase its activity- urge incontinence
3. Oxybutynin and tolterodine cause relation of smooth muscle of bladder
What is the prostate?
The prostate is a male reproductive gland that produces the fluid that carries sperm during ejaculation which surrounds the urethra
What is benign prostatic hypertrophy?
When the prostatic enlarges as they get older, this can press on the urethra and cause urination and bladder problems
What are some symptoms of benign prostatic hypertrophy?
1. Dribbling at the end of urination
2. Inability to urinate (urinary retention)
3. Incomplete emptying of bladder
5. Needing to urinate two or more times per night
6. Pain with urination or bloody urine (infection)
7. Slowed or delayed start of the urinary system
8. Straining to urinate
9. Strong and sudden urge to urinate
10. Weak urine stream
How do you see the signs and test for benign prostatic hypertrophy?
1. Take a complete medical history
2. Perform a digital rectal examination to feel the prostate
Other tests include:
1. Urine flow rate
2. After urination see how much urine is left in bladder
3. Pressure flow studies to measure the pressure as you urinate
4. Urinalysis to check for blood or infection
5. Urine culture to check for infection
6. Prostate specific antigen (PSA) blood test to screen for prostate cancer
7. Cytoscopy- inside of bladder
How do you treat benign prostatic hypertrophy? (medication wise)
1. Alpha-1-blockers are a class of medications used to treat high blood pressure
- Relax the muscles of the bladder, neck and prostate (allows for easier urination)
2. Finasteride and dutasteride lower levels of hormones produced by the prostate
- They reduce size of prostate gland
- Increase urine flow rate
- Decrease symptoms of BPH
(3 to 6 month treatment) (decreased sex drive)
3. Antibiotics used for chronic prostatitis (inflammation of prostate)