Urinary Elimination
The urinary system consists of kidneys and ureters, bladder, and urethra. The
kidneys lie on either side of the vertebral column behind the peritoneum and
against the deep muscles of the back. Normally the left kidney is higher than the
right because of the anatomical position of the liver.
Adequate elimination depends on the coordinated function of the kidneys, ureters,
bladder, and urethra. The kidneys filter waste products of metabolism from the
blood. The ureters transport urine from the kidneys to the bladder. The bladder
holds urine until the volume in the bladder triggers a sensation of urge indicating
the need to pass urine. Micturition occurs when the brain gives the bladder
permission to empty, the bladder contracts, the urinary sphincter relaxes, and urine
leaves the body through the urethra. Bladder serves as a temporary reservoir for
urine. Sphincter guards opening between urinary bladder and urethra. Male urethra
functions in excretory and reproductive systems.
The female urethra is approximately 3 to 4 cm (1 to 1.5 in) long and the male
urethra is about 18 to 20 cm (7 to 8 in) long. The shorter length of the female
urethra increases risk for urinary tract infection due to close access to the bacteria
contaminated perineal area.
Urinary elimination is a basic human function that can be compromised by a wide
variety of illnesses and conditions. It is the nurse’s role to assess urinary tract
function and support bladder emptying.
Act of Urination
Urination, micturition, and voiding are all terms that describe the process of bladder
emptying. Micturition is a complex interaction between the bladder, urinary
sphincter, and central nervous system.
Variables including frequency and factors affecting urination are developmental
considerations, food and fluid intake, psychological variables, activity and muscle
tone, pathologic conditions, and medications. Children cannot voluntarily control
voiding until 18 to 24 months.
• Readiness for toilet training includes the ability to: recognize the feeling of
1
, bladder fullness, to hold urine for 1 to 2 hours, and communicate the sense
of urgency.
• Older adults may experience a decrease in bladder capacity and are at
increased risk for urinary incontinence due to chronic illnesses and factors
that interfere with mobility, cognition, and manual dexterity.
• Social expectations (e.g., school recesses, work breaks) can interfere with
timely voiding.
• Anxiety and stress sometimes affect a sense of urgency and increase the
frequency of voiding. Anxiety can impact bladder emptying due to inadequate
relaxation of the pelvic floor muscles and urinary sphincter.
• Depression can decrease the desire for urinary continence.
• The need for privacy and adequate time to void can influence the ability to
adequately empty the bladder.
• If fluids, electrolytes, and solutes are balanced, increased fluid intake
increases urine production.
• Alcohol decreases the release of antidiuretic hormones, thus increasing urine
production.
• Fluids containing caffeine and other bladder irritants can prompt unsolicited
bladder contractions resulting in frequency, urgency, and incontinence.
• Diabetes mellitus, multiple sclerosis, and stoke can alter bladder contractility
in addition to the ability to sense bladder filling. Patients will experience
either bladder overactivity or deficient bladder emptying.
• Arthritis, Parkinson’s disease, dementia, and chronic pain syndromes can
interfere with timely access to a toilet.
• Spinal cord injury or intervertebral disk disease (above S-1) can cause the
loss of urine control due to bladder overactivity and impaired coordination
between the contracting bladder and urinary sphincter.
• Prostatic enlargement (e.g., benign prostatic hyperplasia or BPH) can cause
obstruction of the bladder outlet causing urinary retention.
2
The urinary system consists of kidneys and ureters, bladder, and urethra. The
kidneys lie on either side of the vertebral column behind the peritoneum and
against the deep muscles of the back. Normally the left kidney is higher than the
right because of the anatomical position of the liver.
Adequate elimination depends on the coordinated function of the kidneys, ureters,
bladder, and urethra. The kidneys filter waste products of metabolism from the
blood. The ureters transport urine from the kidneys to the bladder. The bladder
holds urine until the volume in the bladder triggers a sensation of urge indicating
the need to pass urine. Micturition occurs when the brain gives the bladder
permission to empty, the bladder contracts, the urinary sphincter relaxes, and urine
leaves the body through the urethra. Bladder serves as a temporary reservoir for
urine. Sphincter guards opening between urinary bladder and urethra. Male urethra
functions in excretory and reproductive systems.
The female urethra is approximately 3 to 4 cm (1 to 1.5 in) long and the male
urethra is about 18 to 20 cm (7 to 8 in) long. The shorter length of the female
urethra increases risk for urinary tract infection due to close access to the bacteria
contaminated perineal area.
Urinary elimination is a basic human function that can be compromised by a wide
variety of illnesses and conditions. It is the nurse’s role to assess urinary tract
function and support bladder emptying.
Act of Urination
Urination, micturition, and voiding are all terms that describe the process of bladder
emptying. Micturition is a complex interaction between the bladder, urinary
sphincter, and central nervous system.
Variables including frequency and factors affecting urination are developmental
considerations, food and fluid intake, psychological variables, activity and muscle
tone, pathologic conditions, and medications. Children cannot voluntarily control
voiding until 18 to 24 months.
• Readiness for toilet training includes the ability to: recognize the feeling of
1
, bladder fullness, to hold urine for 1 to 2 hours, and communicate the sense
of urgency.
• Older adults may experience a decrease in bladder capacity and are at
increased risk for urinary incontinence due to chronic illnesses and factors
that interfere with mobility, cognition, and manual dexterity.
• Social expectations (e.g., school recesses, work breaks) can interfere with
timely voiding.
• Anxiety and stress sometimes affect a sense of urgency and increase the
frequency of voiding. Anxiety can impact bladder emptying due to inadequate
relaxation of the pelvic floor muscles and urinary sphincter.
• Depression can decrease the desire for urinary continence.
• The need for privacy and adequate time to void can influence the ability to
adequately empty the bladder.
• If fluids, electrolytes, and solutes are balanced, increased fluid intake
increases urine production.
• Alcohol decreases the release of antidiuretic hormones, thus increasing urine
production.
• Fluids containing caffeine and other bladder irritants can prompt unsolicited
bladder contractions resulting in frequency, urgency, and incontinence.
• Diabetes mellitus, multiple sclerosis, and stoke can alter bladder contractility
in addition to the ability to sense bladder filling. Patients will experience
either bladder overactivity or deficient bladder emptying.
• Arthritis, Parkinson’s disease, dementia, and chronic pain syndromes can
interfere with timely access to a toilet.
• Spinal cord injury or intervertebral disk disease (above S-1) can cause the
loss of urine control due to bladder overactivity and impaired coordination
between the contracting bladder and urinary sphincter.
• Prostatic enlargement (e.g., benign prostatic hyperplasia or BPH) can cause
obstruction of the bladder outlet causing urinary retention.
2
