FUNDAMENTALS OF NURSING

1. URINARY
ELIMINATION

3. Introduction
◦ The urinary system consists of organs that produce and excrete urine from the
body.
◦ Urine contains waste: mostly excess water, salts and nitrogen compounds.
◦ Primary organs are the kidneys
◦ Normal adult bladder can store up to 5 liters.
◦ Also responsible for regulating blood volume and blood pressure.
◦ Regulates electrolytes.

4. Organs of urinary system
◦ The components of the urinary
system include :
◦ the kidneys
◦ the ureters
◦ the urinary bladder
◦ the urethra.

5. Kidney
◦ The kidneys are bean-shaped organs located at
the back of the abdominal cavity.
◦ They lie on either side of the spinal column.
◦ This area is known as the flank area and is against
the muscles of the back.
◦ The external kidney has a notch at the concave
border known as the hilum.
◦ The hilum is the entrance for renal artery, veins,
nerves and lymphatic vessels.

6. Internal structure of kidney
◦ The cortex is the outer layer;
arteries, veins, convoluted tubes
and glomerular capsules
◦ The medulla is the inner layer;
renal pyramids

7. Nephron
◦ 1 million nephrons
◦ The functional unit of the kidney
◦ Remove waste products of
metabolism from the blood
plasma.
◦ Waste products are urea, uric acid,
creatinine, sodium, potassium
chloride and ketone bodies.

8. Urine Formation

9. Ureters, bladder and urethra
◦ Ureters -tubes that carry newly formed urine from the bladder to the kidneys.
◦ Bladder-muscular sac that serves as a reservoir for urine; bladder stretches to
accommodate urine.
◦ Urethra- tube extends from the bladder to the external opening of the urinary
system, the urinary meatus

10. Urine
◦ The formation of urine has 3 processes, filtration, reabsorption and tubular
secretion.
◦ Urine consists of 95% water and 5% solid substances.
◦ The need to urinate is usually felt at 300-350ml of urine in the bladder.
◦ Typically 1000-1500 mL is voided daily.

11. Physical Characteristics of Urine
◦ Odor
–Fresh urine is slightly aromatic –Standing urine develops an ammonia odor –
Some drugs and vegetables (asparagus) alter the usual odor
◦ pH
– Slightly acidic (pH 6) with a range of 4.5 to 8.0 – Diet can alter pH
◦ Specific gravity
– Ranges from 1.010 to 1.025 – Dependent on solute concentration

12. Chemical Characteristics of Urine
◦ Urine is 95% water and 5% solutes
◦ Nitrogenous wastes (organic solutes) include urea, ammonia, uric acid, and
creatinine
◦ Other normal solutes include: – Sodium, potassium, phosphate, and sulfate
ions – Calcium, magnesium, and bicarbonate ions
◦ NaCl is the most abundant inorganic salt in the urine.
◦ Urea is the chief organic solute.
◦ Abnormally high concentrations of any urinary constituents may indicate
pathology
◦ Disease states alter urine composition dramatically

13. Urination
◦ Micturation, voiding, and urination all refer to the process of emptying the
urinary bladder
◦ Stretch receptors- special sensory nerve endings in the bladder wall that is
stimulated when pressure is felt from the collection of urine
– Adult: 250-450mL of urine
– Children: 50-200mL of urine

14. Factors affecting urination
◦ Growth and development
◦ Psychosocial factors
◦ Fluid and food intake
◦ Medications
◦ Muscle tone and activity
◦ Pathologic conditions
◦ Surgical and diagnostic procedures

15. Altered urine production
◦ Polyuria- a.k.a. diuresis
– production of abnormally large amounts of urine by the kidneys
– 2500mL/day for adults
– Causes:
• Excessive fluid intake
• Intake of alcohol and caffeine
• Diabetes mellitus
• Hormone imbalances
• CKD
– Other signs associated with diuresis: polydipsia, dehydration and weight loss

16. ◦ Oliguria
- Voiding scant amounts of urine
- Less than 500mL/day
◦ Anuria
- Voiding less than 100mL/day
- May result from low fluid intake, kidney disease, severe heart failure, burns
and shock
- Usually accompanied by fever and heavy respiration

17. ◦ Frequency
- voiding at frequent intervals that is more often than usual.
- Total amount of urine voided may be normal but amount of each voiding
are small---50-100mL
- May result from increased fluid intake, cystitis, stress, or pressure on the
bladder
◦ Nocturia
- increased frequency at night that is not a result of an increased fluid intake
- Expressed in terms number of times the person gets out of bed to void

18. ◦ Urgency
-feeling that the person must void.
-Usually accompanies psychologic stress, and irritation of the urethra
-Common in young children who have poor external sphincter control

19. ◦ Dysuria
- voiding that is either painful or difficult
- May result from stricture of the urethra, urinary infections, injury to the
bladder and/ or the urethra.
- Described as a burning sensation during voiding
- Burning during micturation if often due to an irritated urethra. Burning
following urination may be a result of bladder infection
- Often associated with urinary hesitancy (delay and difficulty in initiating
voiding)

20. ◦ Enuresis
- repeated involuntary urination in children beyond the age when voluntary
bladder control in normally acquired (4-5yrs)

21. ◦ Urinary incontinence is considered a symptom, not a disease.
- Loss of bladder control
- Types:
• Functional incontinence- involuntary unpredictable passage of urine
• Reflex incontinence- involuntary loss of urine occurring at somewhat
predictable intervals when a specific bladder volume is reached.
• Stress incontinence- loss of urine of less than 50cc occurring with increased
intra-abdominal pressure

22. ◦ Total incontinence- continuous and unpredictable loss of urine.
◦ Urge incontinence- involuntary passage of urine occurring soon after a
strong sense of urgency to void.

23. ◦ urinary retention with overflow - dribbling incontinence that results when
the bladder is greatly distended with urine because of an obstruction
◦ Neurogenic bladder- describes any voiding problem related to neurologic
impairment or dysfunction.

24. ◦ Urinary retention- accumulation of urine in the bladder (as much as 3L) with
associated inability of the bladder to empty itself.
◦ Adult- can hold 250-450ml of urine in the bladder before micturation reflex in
triggered.
◦ Prolonged retention leads to stasis (slowing of the flow of urine) and
stagnation of urine which increases the possibility of UTI.
◦ Retention if distinguished from oliguria or anuria by the distention of the
bladder.
◦ Characterized by small, frequent voiding or absence of urine output