Week 16 - Urology Flashcards
What are the 4 zones of the prostate?
peripheral
fibromuscular
central
transitional
What vessels supply the prostate?
inferior vesical, middle rectal and internal pudendal arteries
What vessels drain the prostate?
prostatic venous plexus draining into the internal iliac veins
What nerve sympathetically innervates the prostate?
Hypogastric
What nerve parasympathetically innervates the prostate?
pelvic
what is the function of the prostate?
secretes proteolytic enzymes into the semen, which act to break down clotting factors in the ejaculate.
how do proteolytic enzymes leave the prostate?
via the prostate ducts
open into the prostatic portion of the urethra
what are the 4 features of the bladder?
apex
body
fundus
neck
how does urine enter and leave the bladder?
enters via left and right ureters
exits via urethra
what is the trigone in the bladder?
area located within the fundus marked by the 2 ureters and urethra
has smooth walls
what muscles in the bladder help it contract during micturition?
detrusor muscles
what are the 2 sphincters in the urethra and what are their functions?
Internal urethral sphincter:
Male – consists of circular smooth fibres, which are under autonomic control. It is thought to prevent seminal regurgitation during ejaculation.
Females – thought to be a functional sphincter (i.e. no sphincteric muscle present). It is formed by the anatomy of the bladder neck and proximal urethra.
External urethral sphincter – has the same structure in both sexes.
It is skeletal muscle, and under voluntary control.
what vessels supply the bladder?
superior vesical branch from internal iliac artery
Males = supplemented by inferior vesical artery
Females = supplemented by vaginal arteries
what vessels drain the bladder?
drained by vesical venous plexus emptying into internal iliac veins
what is the lymphatic drainage of the bladder?
Superolateral aspect = drains to external iliac lymph nodes
Neck + fundus = drain to internal iliac, sacral and common iliac nodes
What nerve supplies the sympathetic innervation to the bladder and what does it cause?
hypogastric nerve (causes relaxation of detrusor muscle .: urine retention)
what nerve supplies parasympathetic innervation to the bladder and what does it cause?
pelvic nerve (contraction of detrusor muscle .: micturition
what nerves supply the somatic innervation to the bladder and what do they cause?
pudendal nerve (external urethral sphincter providing voluntary control of micturition) + sensory (afferent) nerves
What are the 2 main functions of the bladder?
Temporary storage of urine – the bladder is a hollow organ with distensible walls. It has a folded internal lining (known as rugae), which allows it to accommodate up to 400-600ml of urine in healthy adults.
Assists in the expulsion of urine – the musculature of the bladder contracts during micturition, with concomitant relaxation of the sphincters.
what is the max amount of urine that can be held in the bladder?
400-600ml
what is the bladder stretch reflex? When is it seen?
- Bladder fills with urine, and the bladder walls stretch.
- Sensory nerves detect stretch and transmit this information to the spinal cord.
- Interneurons within the spinal cord relay the signal to the parasympathetic efferents (the pelvic nerve).
The pelvic nerve acts to contract the detrusor muscle, and stimulate micturition.
infants before potty training
spinal injuries
neurodegenerative diseases
what are the 2 phases of micturition?
storage
voiding
what innervation is sent to the bladder during the storage phase of micturition?
sympathetic = hypogastric nerve causes relaxation of detrusor muscles by stimulation of B3-adrenoreceptors and constriction of the IUS via stimulation of A1-adrenoreceptors
somatic = pudendal nerve acts on cholinergic receptors to contract EUS
what innervation is sent to the bladder in the voiding stage of micturition?
parasympathetic - pelvic nerve stimulates muscarinic receptors causing contraction of detrusor muscles
what is BPH?
benign prostatic hyperplasia
caused by hyperplasia of the stromal and epithelial cells of the prostate, presents with lower urinary tract symptoms (LUTS)
when is BPH most common?
men over 50
what re the symptoms of BPH?
Hesitancy
Weak flow
Urgency
Frequency
Intermittency
Straining
Terminal dribbling
Incomplete emptying
Nocturia - significant usually if waking up twice or more
*IPSS - scoring system used to assess severity of LUTS
what investigations are done to test for BPH?
Digital rectal exam - assess size, shape and characteristics of prostate
Abdo exam - palpable bladder or other abnormalities
Urinary frequency volume chart - recording 3 days of fluid intake and output
Urine dipstick - assess for infection, haematuria etc
PSA - prostate cancer
what management is given to those with BPH with mild symptoms?
alpha blockers (tamsulosin) - relax smooth muscle, improve symptoms
5-alpha reductase inhibitors (finasteride) - reduce size of prostate
what surgical options are available in BPH with severe symptoms?
Transurethral resection of the prostate (TURP)
Removal of part of the prostate from inside the urethra
Transurethral electrovaporisation of the prostate (TEVAP/TUVP)
Rollerball electrode rolled across prostate, vaporising prostate tissue and creating more expansive space for urine flow
Holmium laser enucleation of the prostate (HoLEP)
Laser used to remove prostate tissue, creating more expansive space for urine flow
Open prostatectomy via abdo or perineal incision
Open procedure to remove prostate
what is the most common cause of acute urinary retention?
BPH
what is acute urinary retention?
new onset inability to pass urine leading to pain and discomfort, with significant residual volumes.
what are some causes of acute urinary retention?
· UTI - cause urethral sphincter to close, especially in BPH individuals
· Constipation - through compression on the urethra
· Severe pain - medications e.g. anti-muscarinics, spinal/epidural anaesthesia can affect innervation to the bladder
Neurological - peripheral neuropathy, iatrogenic nerve damage during pelvic surgery, multiple sclerosis, Parkinson’s, DSD
what are some symptoms of acute urinary retention?
· Acute suprapubic pain
· Inability to micturate
· UTI infection
LUTS symptoms as above
what investigations are done to test for acute urinary retention?
· Bedside bladder scan - volume of retained urine
· Routine bloods - FBC, CRP, U&Es, catherised specimen of urine (CSU)
· Ultrasound of urinary tract - if high pressure retention, assess presence of hydronephrosis
what is the management of acute urinary retention?
Immediate urethral catheterisation - measure volume drained post-catheterisation
Treat underlying cause - e.g. tamsulosin, finasteride started if appropriate
· Check CSU - evidence of infection? Treat with Abx
· Review medications - potential contributing causes? Treat constipation if present
Large retention volume (>1000ml)
Need to be monitored post-catheterisation for evidence of post-obstructive diuresis
No evidence of renal impairment - TWOC
All men with a history of chronic LUTS or a palpably large prostate should be started on tamsulosin. Can have their TWOC >72hrs after commencement.
If TWOC unsuccessful - recatheterise
Further TWOCs attempted (after longer interval in a specialist TWOC clinic)
Failed attempts –> long-term catheter
between what spinal levels are the kidneys found?
T12-L3
what are the 2 main structures of the kidney?
outer cortex
inner medulla
what are some causes of a urinary tract obstruction?
Benign prostatic hyperplasia
Scar tissue in the ureter → makes it hard to micturate
Tumours or cysts in the abdominal area that press on the ureter
Vascular disease and blood clots
GI issues → Crohn’s disease, diverticulitis or a swollen appendix
Ureteral stones
Ureteropelvic junction obstruction → blockage of the ureter at its connection to the kidney
Ectopic ureter → ureter connects to the wrong place in the body
Ureterocele → birth condition that causes swelling in the ureter
Pregnancy, endometriosis or uterine prolapse
what are the symptoms of a urinary tract obstruction?
Pain in the abdomen, lower back or flank pain
Fever, nausea or vomiting
Difficulty urinarting or emptying the bladder
Frequent urination
Recurring UTIs
Haematuria
Cloudy urine
Swollen legs