Urinary System Anatomy Quiz

Urinary Tract

• The urinary tract consists of two kidneys, two ureters, the urinary bladder, and the urethra.

The Kidney

• The kidney has two parts: right and left.
• The kidney has a fibrous capsule, cortex, medulla, collecting ducts, and pelvis.
• The kidney's blood supply comes from the renal artery and renal vein.
• The kidney's function is to produce urine, with an average production of 1ml per minute.

The Ureter

• There are two ureters, one for each kidney.
• The ureter is a hollow muscular canal that is 25cm long.
• The ureter starts at the pelvis of the kidney and ends at the urinary bladder.
• The ureter has abdominal and pelvic parts.
• The ureter's function is to transport urine from the kidney to the urinary bladder.

The Urinary Bladder

• The urinary bladder is a midline hollow sac that lies directly behind the pubic symphysis.
• The bladder has three layers: mucosa (inner), musculosa (middle), and serosa (outer).
• The bladder has a dome, trigone, and relations with the uterus, cervix, and vagina.
• The bladder's function is to store urine.

The Urethra

• The urethra is a fibromuscular tube that is 3-4cm long.
• The urethra has two openings: internal meatus and external meatus.
• The urethra has intrinsic and extrinsic sphincters.
• The urethra's function is to transport urine from the bladder to outside the body.

Micturition Cycle

• The micturition cycle has two phases: filling and voiding.
• During the filling phase, the detrusor muscle is relaxed, and the sensation of fullness becomes more consciously apparent with increasing stored volume.
• During the voiding phase, the levator ani and urethral sphincter muscles relax, and the detrusor muscle contracts.

Mechanism of Continence

• At rest, continence is maintained by low intra-vesical pressure and intra-urethral pressure.
• Factors maintaining low intra-vesical pressure include passive and active factors.
• Factors increasing intra-urethral pressure include the mucosal seal, vascular cushion, urethral sphincters, and the hammock theory.
• The posterior urethro-vesical angle of 90-100° also helps maintain continence.

Mechanism of Continence at Stress

• Continence is maintained during stress by equally transmitted pressure on both the bladder and urethra.
• Additional factors that help maintain continence during stress include the extrinsic striated muscles, the hammock, and kinking of the urinary bladder neck.

Urinary Incontinence

• Urinary incontinence is the involuntary loss of urine.
• Stress urinary incontinence is the involuntary loss of urine on effort or physical exertion.
• Urgency urinary incontinence is the involuntary loss of urine associated with urgency.
• Mixed urinary incontinence is the involuntary loss of urine associated with both urgency and effort.
• Nocturnal enuresis is the involuntary loss of urine during sleep.

Female Urinary Incontinence

• Female urinary incontinence can be classified into transurethral, extraurethral, and functional categories.

Stress Urinary Incontinence

• Stress urinary incontinence is the involuntary loss of urine on effort or physical exertion.
• The mechanism of incontinence involves anatomic and intrinsic sphincteric deficiency factors.
• Urethral hypermobility is a common cause of stress urinary incontinence.

Urgency Urinary Incontinence

• Urgency urinary incontinence is the involuntary loss of urine associated with urgency.
• Contributing factors include weak tissues, pregnancy, childbirth, obesity, and increased intraabdominal pressure.
• Assessment involves a detailed history, examination, and investigations such as urine analysis, voiding diaries, and pad test.

Management

• Non-surgical management is the first step in managing urinary incontinence.
• Non-surgical management includes lifestyle interventions, physical therapies, behavioral therapies, and devices.
• Surgical treatment is considered if non-surgical management is not effective.
• The type of treatment depends on the type of incontinence.