Case 8 Flashcards
what is the urinary bladder composed of? (parts) what happens at each part?
• The urinary bladder is a smooth muscle chamber composed of two main parts:
- The body – urine collects here.
- The neck - is a funnel-shaped extension of the body, passing inferiorly and anteriorly into the urogenital triangle and connecting with the urethra. The lower part of the bladder neck is also called the posterior urethra because of its relation to the urethra.
what is the smooth muscle of the bladder?
detrusor muscle
detrusor muscle
- direction of fibres
- pressure inside bladder - what happens
- how are the smooth muscle cells of the muscle arranged and why
Its muscle fibres extend in all directions.
When contracted, can the pressure inside the bladder is increased. This allows the emptying of the bladder (normal range = ≤ 15-20 cmH20)
Smooth muscle cells of the detrusor muscle fuse with one another so that low-resistance electrical pathways exist from one muscle cell to the other.
- Therefore, an action potential can spread throughout the detrusor muscle, from one muscle cell to the next, to cause contraction of the entire bladder at once.
where is the posterior wall of the bladder? what is on the posterior wall?
On the posterior wall of the bladder, lying immediately above the bladder neck, is a small triangular area called the trigone.
what is the mucosa of the trigone like compared to the remainder of the bladder mucosa?
smooth, in contrast to the remaining bladder mucosa, which is folded to form rugae.
where do the two ureters enter the bladder? how do they pass into the bladder?
The two ureters enter the bladder at the uppermost angles of the trigone.
Each ureter, as it enters the bladder, courses obliquely through the detrusor muscle and then passes another 1-2cm beneath the bladder mucosa before emptying into the bladder.
where does the bladder open into the posterior urethra? how long is it? what composed of? what is the muscle called? what form is it in?
At the lowermost apex of the trigone, the bladder neck opens into the posterior urethra.
This is 2-3cm long, and its wall is composed of detrusor muscle interlaced with a large amount of elastic tissue.
The muscle in this area is called the internal sphincter.
o Its natural tone normally keeps the bladder neck and posterior urethra empty of urine and, therefore, prevents emptying of the bladder until the pressure in the main part of the bladder rises above a critical threshold.
what happens beyond the posterior urethra? what does thin contain in wall?
Beyond the posterior urethra, the urethra passes through the urogenital diaphragm, which contains a layer of muscle called the external sphincter of the bladder.
why type of muscle is the external sphincter? what are the other muscles in the bladder? what does this mean the external sphincter can do? what control are they under?
This muscle is a voluntary skeletal muscle, in contrast to the muscle of the bladder body and bladder neck, which is entirely smooth muscle.
The external sphincter muscle is under voluntary control of the nervous system and can be used to consciously prevent urination even when involuntary controls are attempting to empty the bladder.
- Internal sphincter = smooth muscle = involuntary control (parasympathetic)
- External sphincter = skeletal muscle = voluntary control (somatic)
what is normal urine flow?
20-50 ml/s.
describe the innervation of the bladder
- what is the principal nerve supplying the bladder
• Parasympathetic Innervation (autonomic) - the principal nerve supply of the bladder is by way of the PELVIC SPLANCHNIC NERVES, which connect with the spinal cord through the sacral plexus (S2,3,4):
Sensory nerve fibres(afferent)
- These detect the degree of stretch in the bladder wall.
- Stretch signals from the posterior urethra are especially strong and are mainly responsible for initiating the reflexes that cause bladder emptying.
Motor nerve fibres (efferent)
- These terminate on ganglion cells located in the wall of the bladder.
- Short postganglionic nerves then innervate the detrusor muscle (M3 receptor).
- This aids micturition.
• Sympathetic Innervation (autonomic) - the bladder receives sympathetic innervation from the sympathetic chain through the HYPOGASTRIC NERVES (L2).
These cause relaxation of detrusor muscle (B3 receptor) and contraction of urethra (a1 receptor), thus allowing bladder to fill.
Some sensory nerve fibres also pass by way of the sympathetic nerves and may be important in the sensation of fullness and, in some instances, pain.
• Somatic Innervation (voluntary) - other innervation of the bladder is skeletal motor fibres transmitted through the PUDENDAL NERVE to the external sphincter.
These innervate and provide voluntary control over the skeletal muscle of the external sphincter (ACh). (nicotinic receptor)
Higher centres can override this contraction and cause the external sphincter to relax.
- Parasympathetic nervous system drives the voiding of the bladder - makes the detrusor muscle in the wall contract
- Adrenergic system relaxes the wall of the bladder and constricts the outflow of the bladder
- If your ANS is not working properly (spinal injury or neuropathy in diabetes) it can affect these nerves so affects bladder control
what are the roots of parasympathetic nerve fibres? what does this innervation cause?
• Parasympathetic nerve fibres (S2,3,4) cause:
Contraction of detrusor muscle in the body of the bladder (M3 receptor).
Relaxation of the urethra.
This aids micturition.
what are the roots of sympathetic nerve fibres? what does this innervation cause?
• Sympathetic nerve fibres (T11-L2) cause:
Relaxation of the detrusor muscle in the body of the bladder (B3 receptor).
Contraction of the urethra (a1 receptor).
This aids the filling of the bladder.
what are the roots of the somatic nerve fibres? what does this innervation cause?
• Somatic nerve fibres (S2,3,4) cause:
Contraction of the external sphincter.
Higher centres can override this contraction and cause the external sphincter to relax.
what is micturition? what are the two main steps?
• Micturition is the process by which the urinary bladder empties when it becomes filled.
• This involves two main steps:
1. The bladder fills until the tension in its walls rises above a threshold level.
2. This elicits a nervous reflex called the micturition reflex that empties the bladder or, if this fails, at least causes a conscious desire to urinate.
is the micturition reflex an autonomic spinal cord reflex?
Although the micturition reflex is an autonomic spinal cord reflex, it can also be inhibited or facilitated by centres in the cerebral cortex or brain stem.
what is the composition of urine expelled from the bladder like compared to that flowing out collecting ducts?
Urine that is expelled from the bladder has the same composition as fluid flowing out of the collecting ducts of the kidneys.
urine flows from the collecting ducts into where? causing what? what does this do?
- Urine flows from the collecting ducts into the renal calyces, thus stretching them.
- This increases their pacemaker activity, which in turn initiates peristaltic contractions that spread to the renal pelvis and then downward along the length of the ureter, thereby forcing urine from the renal pelvis to the bladder.
what do the walls of the ureters contain?
smooth muscle
what is the smooth muscle of the ureters innervated by?
innervated by both sympathetic and parasympathetic nerves and by an intramural plexus (nerve plexus within the wall) that extends along the entire length of the ureters.
what are peristaltic contractions in the ureter enhanced and inhibited by?
Peristaltic contractions in the ureter are enhanced by parasympathetic stimulation and inhibited by sympathetic stimulation.
where do the ureters enter? what prevents back flow of urine? what can sometimes happen? what can this lead to?
• The ureters enter the bladder through the detrusor muscle in the trigone region.
The normal tone of the detrusor muscle in the bladder wall tends to compress the ureter, thereby preventing back flow of urine from the bladder when pressure builds up in the bladder during micturition or bladder compression.
- Sometimes, the contraction of the bladder during micturition does not always lead to complete occlusion of the ureter (valve).
- As a result, some of the urine in the bladder is propelled backward into the ureter - vesicoureteral reflux.
- Such reflux can lead to enlargement (dilatation) of the ureters.
- If severe it increases the pressure in the renal calyces and the renal medulla, causing renal dysfunction.
are the ureters supplied with many pain nerve fibres? what happens when a ureter becomes blocked? what is this called? why important?
- The ureters are well supplied with pain nerve fibres.
- When a ureter becomes blocked (e.g. by a ureteral stone), intense reflex constriction occurs, associated with severe pain.
- Also, the pain impulses cause a sympathetic reflex back to the kidney to constrict the renal arterioles, thereby decreasing urine output from the kidney.
- This effect is called the ureterorenal reflex and is important for preventing excessive flow of fluid into the pelvis of a kidney with a blocked ureter.
what are the micturition contractions a result of?
the micturition reflex
describe the micturition reflex
As the bladder is filling, sensory stretch receptors in the bladder wall, especially by the receptors in the posterior urethra, initiate a stretch reflex.
Sensory signals from these stretch receptors are conducted to the sacral plexus through the ‘sensory’ afferents of the pelvic splanchnic nerves and then reflexively back to the bladder through the ‘motor’ efferent fibres of the same pelvic splanchnic nerves.
When the bladder is only partially filled, these micturition contractions usually relax and the detrusor muscles stop contracting, and pressure falls back to the baseline.
As the bladder continues to fill, the micturition reflexes become more frequent and cause greater contractions (more powerful) of the detrusor muscle.
Once a micturition reflex begins, it is “self-regenerative”.
That is, initial contraction of the bladder activates the stretch receptors to cause a greater increase in sensory impulses to the bladder and posterior urethra, which causes a further increase in reflex contraction of the bladder; thus, the cycle is repeated again and again until the bladder has reached a strong degree of contraction.
After a little while, the self-regenerative reflex begins to fatigue and the regenerative cycle of the micturition reflex ceases, permitting the bladder to relax.
what happens to micturition reflexes as the bladder becomes more and more filled?
what happens once the micturition reflex becomes powerful enough?
what happens if this inhibition is more potent in the brain than the voluntary constrictor signals to the external sphincter? if not what happens?
- As the bladder becomes more and more filled, micturition reflexes occur more frequently and more powerfully.
- Once the micturition reflex becomes powerful enough, it causes another reflex, which passes through the pudendal nerves to the external sphincter to inhibit it.
- If this inhibition is more potent in the brain than the voluntary constrictor signals to the external sphincter, urination will occur.
- If not, urination will not occur until the bladder fills still further and the micturition reflex becomes more powerful.
The micturition reflex is a completely autonomic spinal cord reflex, but it can be inhibited or facilitated by centres in the brain. where are these centres located? facilitative or inhibitory?
- Brainstem (pons) – these are strong facilitative and inhibitory centres.
- Cerebral cortex – these are mainly inhibitory but can become excitatory.
although the micturition reflex causes micturition, what normally exerts final control of micturition? how?
higher centres
- The higher centres keep the micturition reflex partially inhibited, except when micturition is desired.
- The higher centres can prevent micturition, even if the micturition reflex occurs, by continual tonic contraction of the external sphincter until a convenient time presents itself.
- When it is time to urinate, the cortical centres can facilitate the sacral micturition centres to help initiate a micturition reflex and at the same time inhibit the external urinary sphincter so that urination can occur.
how is voluntary urination usually initiated?
- Voluntary contraction of abdominal muscles.
- This increases the pressure in the bladder and allows extra urine to enter the bladder neck and posterior urethra under pressure, thus stretching their walls.
- This stimulates the stretch receptors, which excites the micturition reflex and simultaneously inhibits the external urethral sphincter.
usually, all the urine will be emptied with rarely more than how much left in the bladder?
5-10 ml
micturition reflex contraction cannot occur if what happens? what happens in each case? what are common causes?
- The sensory nerve fibres from the bladder to the spinal cord are destroyed, thereby preventing transmission of stretch signals from the bladder.
When this happens, a person loses bladder control, despite intact efferent fibres from the cord to the bladder and despite intact neurogenic connections within the brain.
Instead of emptying periodically, the bladder fills to capacity and overflows a few drops at a time through the urethra.
o This is called overflow incontinence.
A common cause of atonic bladder is crush injury to the sacral region of the spinal cord.
- The spinal cord is damaged above the sacral region but the sacral cord segments are still intact.
As a result, typical micturition reflexes can still occur.
However, they are no longer controlled by the brain. - There is damage to the brain stem.
This interrupts most of the inhibitory signals.
The uninhibited neurogenic bladder results in frequent and relatively uncontrolled micturition.
Facilitative impulses passing continually down the cord keep the sacral centres so excitable that even a small quantity of urine elicits an uncontrollable micturition reflex, thereby promoting frequent urination.
what is the prostate gland?
a compound tubuloalveolar exocrine gland of the male reproductive system.
what is function of prostate? fluid is what volume of the semen? along with what?
The function of the prostate is to secrete a slightly alkaline fluid, milky/white in appearance, that in humans constitutes roughly 30% of the volume of the semen along with spermatozoa and seminal vesicle fluid.
- Antegrade ejaculation (prostate closes to allow for antegrade instead of retrograde ejaculation)
- Contributes to 25% ejaculate volume
- Milieu for sperm to thrive - nutrition, antimicrobial (Zn, selenium)
- Prostatic specific antigen (PSA) enzyme (controls ejaculate) - semen coagulation, semen liquefaction
what does the alkalinity of semen do? how is semen made alkaline?
- The alkalinity of semen helps neutralise the acidity of the vaginal tract, prolonging the lifespan of sperm.
- Semen is made alkaline overall with the secretions from the other contributing glands - seminal vesicle fluid.
describe difference between spermatozoa expelled together with mainly seminal vesicular fluid compared to those expelled in prostatic fluid?
Better motility
Longer survival
Better protection of the genetic material
what does the prostate also contain (other than glands)?
some smooth muscles that help expel semen during ejaculation.
structure of prostate gland
- size
- where
- within
- what does urethra merge with
- how can prostate be divided
- does it have a capsule
- where is it sheathed
- A healthy male prostate is the size of a walnut.
- It surrounds the urethra just below the urinary bladder and can be felt during a rectal exam.
- Within the prostate, the urethra coming from the bladder is called the prostatic urethra and merges with the 2 ejaculatory ducts (from the seminal vesicles – one form each side of the body).
- The prostate can be divided in 2 ways: by ZONE or by LOBE.
- The prostate does not have a capsule; rather an integral fibromuscular band surrounds it.
- It is sheathed in the muscles of the pelvic floor, which contract during the ejaculatory process.
what is the zone classification used for? what are the different zones?
in the pathology of the prostate
- transition zone
- peripheral zone
- central zone
- fibromuscular zone (anterior zone)
transitional zone
- what percentage of gland at puberty
- where
- what special about it
- what responsible for
• Transitional zone – up to 5% of gland at puberty
This zone surrounds the proximal urethra.
It is the region of the prostate gland that grows throughout life
Therefore, responsible for the disease of benign prostatic hyperplasia (BPH)
- about 30% of prostate cancer happens here
peripheral zone
- what percentage of gland
- where
- what does it surround
- how big
- what important about it
- what responsible for
• Peripheral zone – up to 70% of gland
The sub-capsular portion of the posterior aspect of the prostate gland that surrounds the distal urethra.
This region is the largest and closest to the rectum - can easily be felt during a digital rectal examination (DRE).
70–80% of prostatic cancers originate here
central zone
- what percentage of gland
- what does it surround
• Central zone – up to 25% of gland
This zone surrounds the ejaculatory ducts.
fibromuscular zone
- what percentage of gland
- what is it
- what is it composed of and what not
• Fibromuscular zone – up to 5% of gland
This isn’t actually a zone but rather a sheath on the anterior aspect of the prostate.
This zone is usually devoid of glandular components, and composed of muscle and fibrous tissue
what is the male sexual response? what does sperm go through? what causes excretion?
During male ejaculation, sperm is transmitted from the ductus deferens into the male urethra via the ejaculatory ducts, which lie within the prostate gland.
During orgasm, smooth muscle tissue in the prostate contracts in order to push semen through the urethra.
It is possible for men to achieve orgasm solely through stimulation of the prostate gland.
what are the prostatic secretions like? what composed of?
The prostatic secretions are a milky white mixture of simple sugars (such as fructose and glucose), enzymes, and alkaline chemicals.
in the secretions, what percentage is the protein content? what does it include?
less than 1% Proteolytic enzymes – to break down coagulants and other proteins, to make the semen more viscous Citric acid Prostatic acid phosphatase Beta-microseminoprotein Prostate-specific antigen (PSA) Zinc – antimicrobial
what do the sugars secreted by the prostate function as?
as nutrition for sperm as they pass into the female body to fertilize ova.
what do enzymes in the secretions do?
they work to break down proteins (coagulants) in semen after ejaculation to free sperm cells from the viscous semen.
what do the alkaline chemicals in the prostatic secretion do?
neutralise acidic vaginal secretions to promote the survival of sperm in the female body.
regulation of growth and division
- where is testosterone produced
- what happens to it
- what is the ultimate mediator of prostatic growth
- how
- what can also stimulate growth
Testosterone is produced in the testicles.
It travels to the prostate and is converted to dihydrotestosterone (DHT) in the stromal cells by the action of the enzyme type 2 5α-reductase.
Dihydrotestosterone (DHT) is the ultimate mediator of prostatic growth as it causes CELL GROWTH and INHIBITS APOPTOSIS.
DHT binds to nuclear androgen receptors, which regulate the gene expression that support the growth and survival of prostatic epithelium and stromal cells.
Although testosterone can also bind to androgen receptors and stimulate growth, DHT is 10 times more potent.
Binding of DHT to androgen receptor (AR) activates the transcription of androgen-dependent genes.
is DHT a direct mitogen for prostate cells?
no, instead DHT-mediated transcription of genes results in the increased production of several growth factors and their receptors.
what is the most important among these growth factors transcribed through DHT binding to receptor? what are other ones produced in BPH? what do they do?
Most important among these are members of the fibroblast growth factor (FGF) family, and particularly FGF-7 (keratinocyte growth factor).
Other growth factors produced in BPH are FGF-1 and FGF-2 which promote fibroblast proliferation.
what is through to contribute to BPH?
Although the ultimate cause of BPH is unknown, it is believed that DHT-induced growth factors act by increasing the proliferation of stromal cells and decreasing the death of epithelial cells.
what may exacerbate clinical symptoms of lower urinary tract obstruction caused by prostatic enlargement?
by contraction of prostatic smooth muscle mediated by α1-adrenergic receptors.
how is the flow of urine through the prostatic urethra controlled?
The urethra runs from the bladder, through the prostate, and out through the penis.
The muscle fibres of the prostate are wrapped around the urethra and are under involuntary nervous system control (SNS – hypogastric nerve (a1)).
These fibres contract to slow and stop the flow of urine.
give a summary of the male genital system
- pathway
- roles of different parts
- The male genital system begins with the 2 testis where sperm is produced.
- The epididymis is system of convoluted small tubules leading from each testis and emptying into the vas deferens.
- After being joined by the duct of the seminal vesicles, the vas deferens becomes the ejaculatory duct which enters the prostate where it joins with the urethra to convey the sperm contained in semen to the penis.
- The walnut sized prostate gland is situated just beneath the bladder and encircles the upper part of the urethra.
- It secretes alkaline fluids rich in enzymes and prostaglandins.
- This secretion is important to the survival and performance of the sperm.
- The seminal vesicles also play an important role in contributing secretions which enhance the sperms chance of success.
- During ejaculation the connection between the bladder and the urethra is closed while the prostate, seminal vesicles, urethra and the penis all undergo rhythmical contraction moving forward the semen which is composed semen plus secretions from the prostate, seminal vesicles and minor glands.
what is the aging male prone to developing?
enlargement of the prostate known as BPH (benign prostate hyperplasia)
what does the prostate contain? what happens in BPH?
• The prostate contains small glands, muscle fibres and connective tissue.
In BPH all of these enlarge, resulting in the enlargement of the prostate gland.
what are the first changes in BPH?
first changes in BPH involve proliferation of glandular tissue in the transitional zone.
what is constantly happening in prostate? what is thought to be an important factor in causing BPH?
- New cells are constantly being formed by division as a result of the pathogenesis of BPH.
- Room has to be made for these new cells by a special process of apoptosis so that in normal health the number of cells being produced is balanced by the number of cells being removed.
- Impairment of apoptosis is thought to be an important factor in causing BPH.
what happens as the prostate enlarges? what does this cause?
it compresses the prostatic urethra, causing disruption to the normal flow of urine.
when epithelial cells multiply excessively in either BPH or in prostate cancer, they may release what? why normally released? why do levels increase? what is the difference in this release between BPH and prostate cancer?
• When epithelial cells multiply excessively in either BPH or in prostate cancer, they may release an excessive amount of a glycoprotein called prostate specific antigen (PSA) into the circulation (normal range = 0-4ng/ml):
Normally, the prostate epithelial cells secrete prostate ‘specific’ antigen (PSA). This is required to liquefy the semen.
The level of this will increase if the prostate enlarges because there are more epithelial cells secreting PSA.
In prostate cancer, there are more cells than in BPH. Therefore, in prostate cancer, the level of PSA in the blood is greater than that in BPH.
what are risk factors for BPH?
- Age and Male
- Androgens
- Functional androgen receptors
- Obesity
- Diabetes (& elevated fasting glucose)
- Dyslipidaemia
- Oestrogens
- Genetic
what reduces risk of BPH?
- Castration
- Moderate/severe physical exercise
- Weight loss
- Modification of cardiovascular risk
how common is BPH? in which age? what percentage of men aged 40 have histologic evidence? how many of those with microscopic evidence have clinically detectable enlargement of the prostate and develop clinical symptoms? what percentage of 71-80 year olds have BPH on autopsy?
• BPH is an extremely common disorder in men over 50-65.
• Incidence:
Histologic evidence can be seen in approximately 20% men aged 40.
Prevalence of BPH after Autopsy (left)
Prevalence of BPH after Clinical (right)
23% aged 41-50 yrs 14% aged 40-49 yrs
42% aged 51-60 yrs 24% aged 50-59 yrs
71% aged 61-70 yrs 43% aged 60-69 yrs
82% aged 71-80 yrs 40% aged 70-79 yrs
Only 50% of those who have microscopic evidence of BPH have clinically detectable enlargement of the prostate, and of these individuals, only 50% develop clinical symptoms.
30% of white Americans over 50 years having moderate-severe symptoms.
what are the symptoms of BPH?
• BPH may cause lower UT symptoms.
• Storage Symptoms:
Going frequently to pass urine
A feeling that the bladder is full (urgency)
Waking up at night to pass urine (nocturia)
Leakage of urine when one does not get to the toilet in time (urge incontinence)
• Voiding Symptoms:
Needing to wait for the stream to start (hesitancy)
Weak stream
The stream starts and stops intermittently
Having to push and strain to pass urine
Dribbling at the end of urination
Sensation of incomplete bladder emptying
• Sometimes, despite urination, the bladder may not empty completely causing a large post-void residual urinary problem, increasing the risk of infection/ bladder stone formation/ cancer development.
what are complications of BPH?
- Infection <1 – 12%
- Renal Failure < 2.5%
- Bladder calculi 0.3 – 3.4%
- Incontinence <1%
- Retention 1 – 2%/yr
- Haematuria
what are investigations for BPH?
- Abdominal examination – usually palpate to check for a distended bladder.
- Rectal examination – prostate feels enlarged but smooth. (nodules would indicate cancer)
what are two types of drug treatments for BPH?
- anti-androgen
- alpha1-adrenergic receptor antagonists
anti-androgen
- what are examples
- mechanism of action
- effect on PSA
- Finasteride, Dutasteride
- Block the enzyme 5α-reductase type 2.
- This slows the conversion of testosterone into DHT, thus slowing down the growth of the stromal and epithelial prostate cells.
- This also promotes apoptosis.
- Reduces PSA (due to promotion of apoptosis)
- 5-alpha reductase inhibitors
- slowly shrink the prostate so that is stops pressing on the urethra, making it easier to urinate
- can shrink the prostate by around a quarter after 6 to 12 months of treatment
- usually offered these if your prostate is very large – because they work particularly well in men who have a larger prostate
- e.g. finasteride, dutasteride
- reduce the amount of PSA in your blood – means doctor will need to change way they look at any PSA tests you have
what are the benefits of anti-androgens?
Safe Reduce prostate volume Reverse pathology Reduced risk of complications Reduce risk of surgery
what are the drawbacks of anti-androgens?
Slow Acting Erectile Dysfunction Gynaecomastia Reduced Libido Reduce PSA too much
alpha1-adrenergic receptor antagonists (alpha-1 blockers)
- examples
- dose
- mechanism of action
- effect on PSA
- Tamsulosin, Alfuzosin, Doxazosin
- Competitive inhibition for the binding site of the α1-adrenergic receptors.
- Causes prostatic smooth muscle relaxation.
- This reduces urethral occlusion.
- These drugs may also encourage apoptosis.
- No effect on PSA
• Tamsulosin (Flomax) - 0.4 mg od • Alfuzosin (Xatral) - 10 mg od • *^ Doxazosin (Cardura) - 1 - 8 mg od • requires titration ^ antihypertensive
- Alpha-blockers
- relax muscles in prostate and around opening of the bladder, making it easier to urinate
- they don’t cure an enlarged prostate but they can help to relieve symptoms
- usually first type of medicine you will be offered, unless your prostate is very large
e. g. Tamsulosin, alfuzosin, doxazosin, terazosin
what are the benefits of alpha1-adrenergic receptor antagonists?
Quick Acting
Safe
Selective
Long Lasting
Advantages: • Rapid onset • Safe (very) • Doesn’t alter PSA • Symptoms improvement maintained
what are the drawbacks of alpha1-adrenergic receptor antagonists?
Dizziness
Drowsiness
Headaches
Little or no sperm on edjaculation
Side effects:
• Postural hypotension - 2 - 5% (due to receptors in arterioles)
• Retrograde ejaculation (relaxed prostate at bladder neck) (means its working)
• Headaches
how are these drugs given, together or separately? what can also be given?
- Both these drugs are given in combination because the anti-androgen drugs are better, but they are short acting.
- Phytotherapy may also be used – ‘saw palmetto’ extracts.
- In acute retention or retention with overflow, the first priorities are to relieve pain and to establish urethral catheter drainage.
when does BPH require surgery?
Deterioration in renal function or the development of upper tract dilatation requires surgery.
what surgical procedures can be carried out? (BPH)
Bladder neck incision
Trans-urethral resection of prostate (TURP)
Holium laser enucleation of prostate (HOLEP)
Open prostectomy
Prostatic stent
transurethral resection of the prostate (TURP)
- when is it used, what line of therapy
- what happens
Transurethral resection of the prostate (TURP)/Transurethral Prostatectomy
• This has been the gold standard in terms of reducing symptoms, improving flow rates, and decreasing post-voiding residual urine.
• It is indicated as a first line of therapy in recurrent urinary retention.
• If urethral catheterisation is impossible, suprapubic catheter drainage should be done.
TURP (transurethral resection of the prostate)
- Remove parts of the prostate that have grown too large and are pressing on the urethra
- Most common type of surgery for an enlarged prostate
- During the operation, the surgeons passes a thin tube up your penis into your urethra
- They then pass an electrically-heated wire loop through the tube and use it to remove small pieces of prostate tissue
TURP
- what is it
- when necessary
- anaesthesia
- describe procedure
• A surgical procedure that removes part/all of the prostate.
• This would be necessary if:
The first treatments for prostate enlargement, such as medication, fail to control symptoms.
An enlarged prostate leads to complications such as bladder stones, infections or difficulty emptying it.
• This is performed under general/spinal anaesthesia:
General – unconscious throughout the procedure
Spinal/epidural – awake throughout but not feel anything
- A device called the resectoscope is used which is a thin metal tube consisting of a light, a camera and a loop wire.
- The resectoscope is inserted into the urethra and guided to the site of the prostate.
- An electric current is used to heat the loop of wire, and the heated wire is used to cut away the section of your prostate that is causing the symptoms.
- After the procedure, a catheter is used to pump saline water into the bladder and flush away pieces of prostate that have been removed.
- Before the surgery, NaCl is administered IV.
- This is to make the smooth muscles in the prostate and the bladder more apparent.
- Glycine may also be used for this purpose, but the prostatic venous sinuses absorb this – it is then metabolized in the portal bed and kidneys. Ammonia is a major by-product of glycine metabolism.
what are the advantages of TURP?
No strain to urinate More control over holding in urine No more nocturia Stronger stream of urine No more pads
what are the disadvantages of TURP?
Loss of ability to ejaculate (retrograde ejaculation – 70%) and ED (erectile dysfunction)
Stricture (narrowing)
HOLEP
- what is this
- what happens
- what are advantages
Holmium Laser Enucleation of the Prostate (HOLEP)
• An alternative to this method is the Holmium laser enucleation of the prostate (HOLEP):
In this a laser is used to separate excess tissue from the prostate into the bladder and the tissue is then removed.
HOLEP causes less blood loss, involves a shorter stay in hospital and is suitable for moderate to large prostates.
pathogenesis of BPH
- Mainly due to impaired cell death – lack of apoptosis.
- This results in the accumulation of senescent cells in the prostate.
- Androgens (mainly DHT), which mediate the development of BPH, can not only increase cellular proliferation, but also inhibit cell death.
- Stromal cells are responsible for androgen-dependent prostatic growth because the type 2 5α-reductase enzyme is only found in the stromal cells.
• As well as the enlargement of the glandular tissue, fibroblasts also proliferate and enlarge.
This is because of excessive FGF growth factors.
As a result of this fibrosis, the bladder wall can’t contract properly and so there is residual urine volume left over always, increasing the risk of infections etc.
what happens to growth and multiplication in prostate cancer? what happens in addition to this?
- In prostate cancer the growth and multiplication of cells escapes from normal control.
- In addition there is impairment of apoptosis (usually a gene mutation of p53).
where does prostate cancer usually occur?
in the peripheral zone
what happens in prostate cancer compared to BPH? (in terms of cell multiplication and subsequent effects)
- Unlike the situation in BPH where cell multiplication is much more controlled, in prostate carcinoma the malignant cells multiply out of control, begin to invade the stroma which is the connective tissue of the prostate and extend beyond it to the surrounding structures such as the seminal vesicles.
- Having breached the capsule, the tumour is now able to spread more widely.
