Flashcards in Bladder and Micturation Deck (49):
how can you describe the layers of the bladder?
outer peritoneum, layer of smooth muscle and CT (detrusor muscle), inner mucosal layer
How are the urethral sphincters made in men vs. women?
women = smooth muscle fibers in the bladder neck that make up the sphincter
men = smooth mm in bladder neck makes a ring and works with prostate
In the female, what is responsible for continence?
the intrinsic sphincter, comprised of bladder neck muscle fibers and the mid-urethral complex
Is there a difference in what makes a male/female continent?
Yes, the prostate and the bladder work together to make the instrinsic sphincter in the male
*intrinsic sphincter is responsible for continence in both sexes, but the makeup of the sphincter is slightly different
What does the parasympathetic nervous system innervate in the lower urinary tract?
PNS = detrusor muscle - activation results in detrusor muscle contraction and micturation
What does the sympathetic nervous system innervate in the lower urinary tract?
SNS = inhibits detrusor mm contraction, increases tension in the smooth mm of the bladder neck and proximal urethra PREVENTING MICTURATION UNTILL PARASYMP INNERVATION
From where does the motor innervation of the lower urinary tract arise?
S2 - S4 of the spinal cord
*both control voluntary mm of bladder, pelvic floor and urethral sphincter AND carries stretch receptor data from spinal cord to pons
The hypogastric nerves are part of what branch?
Hypogastric nerves = sympathetic branch. arise from T10-L2
The Pelvic nerves are part of what branch of the nervous system?
Pelvic = Parasympathetic (p = p)
* come from sacral plexus
The pudendal nerves carry what fibers?
Lower motor neurons make up the pudendal nerves
*innervate the muscles of the pelvic floor and the external urethral sphincter
Diseases such as dementia, stroke, parkinsonism all affect what part of the brain and therefore mess with what part of the lower urinary tract?
These diseases inhibit cortical function (mess with the cortex in the brain), which will stop the voluntary inhibition of micturation
*THESE DISEASES RESULT IN INCONTINENCE
what do disturbances in the storage function result in?
frequency, urgency, urge incontinence
*storage phase = interrelated and coordinated neural and neuromuscular responses allowing bladder to adapt to increasing volume with little increase in pressure
What is the afferent response of the storage reflex and what might cause dysfunction?
*afferent activity is generated by filling of the bladder
*sensory fibers in the pelvic nerve enter the sacral cord via the sacral DRG
*DYSFUNCTION of the unmyelinated C fiber afferents during spinal cord injury OR MS will lead to reorginization of reflex
What is the efferent response of the storage reflex and what might cause dysfunction?
*efferent responses to bladder filling are controlled at supraspinal levels by activating somatic (pudendal) motor neurons in anterior horn of the sacral spinal cord
*efferent responses are associated with inhibition of the detrusor motor neuron combined somehow with cortical inhibition???
*DYSFUNCTION - can result from stroke, frontal lobe lesions, MS, SCI can all impair inhibitor input resulting in detrusor overactivity
*detrusor activity means micturation
Disturbances in the micturation cycle and thus voiding result in what symptoms?
hesitancy, weak stream, incomplete bladder emptying, retention
What are the 5 steps of the micturation cycle?
1) increase in bladder wall tension
2) afferent input overcomes the pontine micturation center threshold and provides cortical egress making micturation begin
3) pudendal nerve activity ceases, external sphincter/pelvic floor relaxes, detrusor neurons are freed and discharge
4) proximal urethra opens
5) bladder immediately contracts
What nerve impulses are occurring when the bladder is contracting?
when voiding occurs, sympathetic and somatic tone decrease and parasympathetic mediated impulses cause the bladder to contract
What kind of neurons make up the pelvic nerve afferents and what do they do?
pelvic nerve afferents, which monitor the volume of the bladder and the amplitude of bladder contractions consist of small myelinated A-delta fibers and unmyelinated C-fibers
Somatic pudendal nerves have what effect on the bladder and the urethra sphincter?
somatic pudendal nerves inhibit bladder contraction and stimulate the urethra to contract (they inhibit micturation)
Lumbar sympathetic nerves have what effect on the bladder and the urethra sphincter?
The lumbar sympathetic nerves act in the same way as the somatic pudendal nerves do (inhibit micturation by stimulating urethral sphincter contraction and inhibiting bladder contraction)
What effect on the bladder and urethra sphincter do the pelvic parasympathetic nerves have?
The pelvic parasympathetic nerves (p = p) will increase bladder contraction and decrease urethral sphincter contraction
*they aid in micturation
What would a lesion in the cortex or brainstem do to urination?
detrusor = hyperactive
external sphincter = normal
symptom = incontinence due to lack of inhibition
What would a spinal cord injury or MS do to urination?
Detrusor = hyperactive
external sphincter = hyperactive
symptom = dyssinergia
* in this neurogenic disorder, the urethral sphincter muscle, instead of relaxing completely during voiding, dyssynergically contracts causing the flow to be interrupted and the bladder pressure to rise.
A sacral cord injury, nerve root injury, or nerve lesion would have what effect on urination?
detrusor = complete areflexia
external sphincter = normal/hyperactive
Symptom = inability to void
what two major categories for voiding dysfunction exist?
outflow dysfunction and bladder dysfunction
*both are subdivided into overactive or underactive
overactive outflow dysfunction means what symptom?
underactive outflow dysfunction means what symptom?
overactive bladder dysfunction means what symptom?
underactive bladder dysfunction means what symptom?
what are the three main categories of incontinence we discussed?
stress, urge, overflow
(others are unconscious, continuous leakage, nocturnal enuresis, post-void dribble, extra-urethral incontinence, geriatric)
If someone has a CC of incontinence, what are the goals for the office evaluation?
*nature of incontinence
*degree to which it interferes with lifestyle
*predisposing medical/surgical conditions
*prior medical/surgical therapies
*direct appropriate and effective therapy
what elements of the past medical history are important in incontinence evaluation?
DM, bowel problems/constipation, neurological disorders (prior CVA, MS, parkinson's)
What are the surgical procedures you want to nail down in the incontinent patient's history?
*Radical pelvic surgery (prostectomy, APR=abdominal perineal resection)
*bladder outlet procedures
What elements of your physical exam are imperative for the incontinent patient evaluation?
*abdominal (obesity, distended bladder, prior surgical scars)
*neurological (mental status, sensory function, motor function, reflex integrity)
*back/spine (skelatal deformities, scars from trauma/surgery, tuft of hair, skin dimple both of which indicate spina bifuda)
*GU (leakage with cough and DRE=digital rectal exam)
What major landmarks fall in the following dermatomes?
T4-5 = nipples
T10 = umbilicus
L1 = labia majora
L2 = labia minora
L3 = front of knee
S1 = sole and lateral foot
S3-5 = perineum and anus
What office evaluation reflexes can be checked suggesting sacral nerve damage?
*voluntary sphincter contraction during DRE
*Deep tendon reflexes
*bulbocavernosus reflex (S2-4)
What does the voluntary sphincter contraction show you?
*voluntary sphincter contraction during DRE (absence can indicate sacral or peripheral nerve injury)
what does the anal wink reflex show you?
*(touching mucocutaneous junction of perianal skin contracts anal sphincter and the absence of this suggests sacral nerve dysfunction)
What do the deep tendon reflexes show you?
Hyperactive = upper motor neuron lesions
Hypoactive = lower motor neuron lesions
Quadriceps/patellar = L3-4
Achilles tendon = L5, S1-2)
How can you rule out neurologic disorders in the diagnosis of incontinence?
reflexes, and look for redicular pain, paresthesias, muscle weakness, diminished sensation or ocular symptoms
What are the treatment options for urinary control?
What are the pharmacological treatments for overactive bladder?
*antimuscarinic agents = mainstay
*symptoms relieved by inhibition of involuntary bladder contractions or increased bladder capacity
*side effects = dry mouth, dry eyes, blurred vision, constipation, GERD, CNS effects
Muscarinic receptors are part of what nervous system?
*muscarinic acetylcholine receptors
*acting as the main end-receptor stimulated by acetylcholine released from postganglionic fibers in the parasympathetic nervous system.
What are the three drugs that antagonize the efferent neuron action on the bladder?
*treatment of overactive bladder
*Atropine, oxybutynin, tolterodine (all anticholinergics)
What makes oxybutynin have the side effects it does?
*oxybutynin = anticholinergic (treatment for overactive bladder)
*extensive first pass CYP3A4 metabolism results in many active metabolites, and one of these is responsible for side effects
*dry mouth, dry eyes, constipation, CNS impairment
what's up with neurogenic detrusor overactivity?
*aka overactive bladder syndrome*
Urinary incontinence due to detrusor overactivity associated with a neurologic condition, such as multiple sclerosis (MS) or spinal cord injury (SCI), results when the spinal cord and bladder do not communicate effectively.
*For people living with MS, this occurs because they develop lesions on the spinal cord, while people with SCI have irreversible nerve damage, resulting in the inability of the spinal cord and bladder to communicate effectively.
*As a result, the bladder muscle involuntarily contracts, increasing the pressure in the bladder and decreasing the volume of urine the bladder can hold, which causes the individual to leak urine frequently and unexpectedly.
What is stress urinary incontinence?
SUI = stress urinary incontinence
*involuntary, sudden loss of urine during increases in intra-abdominal pressure (laughing, sneezing, coughing)
*if bad enough, exercise or routine activity can cause leakage
*AKA = sudden urine loss, leaking, dripping, flooding
What are the pharmalogical treatments for stress incontinence?
alpha-agonists and estrogen
*Alpha-agonists - phenylpropanolamine, pseudoephedrine, ephedrine
*decent improvement in symptoms
*side effects = hypertension, arrhythmias, anxiety, might interact with estrogen