Urinary
System
While viewing this power point
Identify
and listening to the presentation
partsyouofareUrinary
system
going to write
the
urinary system QUIZ.
Write 4 multiple choice
questions and 1 short answer
question. Including the correct
answer from information
discussed today
Your multiple choice question
must include 4 reasonable
choices.
 Removes waste
 Maintains acid-base
balance of body
 Parts include:
 2 KIDNEYS
 2 URETERS
 BLADDER
 URETHRA
 2 bean shaped organs
 Protected by ribs and fat
 Each kidney is found in mass of fatty tissue
(adipose capsule)
 2 main sections:
 Cortex: outer layer, contains most of the
neurons that aid in production of urine
 Medulla: inner layer, contains most of tubes
that carry urine from the nephrons through
the kidneys
Nephrons
 Microscopic filtering
units
 Over 1 million/kidney
 Contains glomerulus
 Cluster of capillaries that
filter waste
 Bowman’s capsule
 Surround glomerulus
picks up filtered materials
and passes it to the
convoluted tubule
 Substances needed by the
body are reabsorbed and
returned to the capillaries
Nephrons
 At the end, most of the
water, sugar, vitamins and
salts have been
reabsorbed
 Excess salts, water, wastes
remain in the tubule and
become urine
 Urine enters collecting
ducts (tubes) in the
medulla
 Collecting tubes empty
into the renal pelvis (first
section of the ureter)
Ureters
 2 muscular tubes 10-12 inches long
 One extends from the renal pelvis to the
bladder
 Peristalsis: a wavelike motion of the
involuntary muscle that moves urine
through the ureter from the kidney to the
bladder
Bladder
 Hollow muscular sac
 Lining folds called rugae –
disappears as muscles of
bladder allow it to expand
and fill with urine
 3 layers of visceral muscle
 Urge to void occurs when
bladder contains 1 cup
 Circular sphincter muscle
 Control bladder opening
 Can’t be controlled by infants
 FUNCTIONS:
 Receives urine from
ureters
 Stores urine until
eliminated from body
Urethra
 Tube carries urine from
bladder to outside
 External opening called
meatus
 Different in male/females
 Females shorter
 Opens in front of vagina or
passes through the penis
 Male: carries both urine from
urinary system and semen
from the reproductive system
Urine
 Liquid waste
 95% water
 1 ½ - 2 quarts produced daily
 Excreting waste products
 Urea
 Creatinine
 Uric acid
 The Concentration of components in a urine sample depends
on osmotic movement of water
Normal Urine Is a clear, sterile solution, yellow
color (pigment urobilin) generated in kidneys
5 Homeostatic Functions of Urinary System
• Regulate blood volume and blood pressure:
• by adjusting volume of water lost in urine
• releasing erythropoietin and renin
• Regulate plasma ion concentrations:
• sodium, potassium, and chloride ions (by controlling
•
quantities lost in urine)
calcium ion levels (through synthesis of calcitriol)
• Help stabilize blood pH:
• by controlling loss of hydrogen ions and bicarbonate ions
in urine
5 Homeostatic Functions of Urinary System
• Conserve valuable nutrients:
• by preventing excretion while excreting organic
waste products
• Assist liver to detoxify poisons
Blood Supply of the Kidney
 Approximately ¼ of the total blood supply of the body
passes through the kidneys each minute
 Renal artery branches inside the kidney
 Venous blood leaves the cortex and medulla
 Small veins join the renal vein
Acidosis
 Lactic acidosis:
 develops after exhaustive muscle activity
 (bulging muscles can cut off blood supply)
 due to anaerobic respiration
 Ketoacidosis:
 Lower blood pH, higher acid, due to presence of ketones
 develops in starvation or diabetes
 Body does not have sufficient glucose/glycogen to sustain
metabolic activity

Muscle loss can occur - dieting
How do the Kidneys
control of Blood pH?
By H+ removal and bicarbonate
production at kidneys
ADH – antidiuretic hormone
 Hormone causes special water channels to appear
 Increases rate of osmotic water movement
 Higher levels of ADH increases:
 number of water channels
 water permeability of ducts and collecting system
 No ADH, water is not reabsorbed
 All fluid reaching ducts is lost in urine producing
large amounts of dilute urine
The Hypothalamus
 Continuously secretes low levels of ADH:
 At normal ADH levels:
 collecting system reabsorbs 16,800 ml fluid/ day
(9.3% of filtrate)
 A healthy adult produces:
 1200 ml urine per day (0.6% of filtrate)
 Polyuria:
excess urination
Key Terms
 Oliguria: below normal urination
 Anuria: absence of urination
 Hematuria: blood in urine
 Nocturia: urination at night
 Dysuria: painful urination
 Retention: inability to empty bladder
 Incontinence: involuntary urination
 Inflammation of the bladder
 More common in females due to shortness of urethra
Symptoms:
• Frequent urination
• Dysuria and burning
• Bladder spasm
• Hematuria
• ? Fever ?
Treatment:
• Antibiotics and increased fluid intake
Glomerulonephritis
 Inflammation of the glomerulus
 Usually follows strep infection
 Can be acute or chronic
 Symptoms: hematuria, hypertension, edema,
fatigue, congestive heart failure, renal failure, death
 Treatment: treat symptoms
 Low salt diet, high blood pressure medicine, dialysis,
transplant
Pyelonephritis
 Inflammation of kidney tissue and renal pelvis
 Usually caused by pus forming bacteria
 Symptoms: chills, fever, back pain, dysuria,
hematuria and pyuria
 Treatment: antibiotics, increased fluid intake
Renal Calculi
 Kidney stone formed when salts in urine settle
 Small stones can be eliminated in urine
 Large stones may become lodged
 Symptoms: sudden pain, hematuria and retention
 Treatment: increase fluids, pain meds, strain urine
w/ gauze, lithotripsy, possible surgery
Renal Failure
 Kidneys stop functioning
 Acute
 Caused by injury, poisoning, dehydration
 Prompt treatment leads to good prognosis
 Chronic
 Progressive loss of kidney function caused by
glomerulonephritis, hypertension, toxins and
endocrine disease.
 Waste accumulates and affects body systems
Uremia
 Toxic condition where urinary waste is in
bloodstream
 Caused from any condition that affects proper
function of kidneys
 Symptoms: n/v, ammonia breath, anuria, headache
and confusion, coma/death
 Treatment: restrictive diet, dialysis, transplant
Urethritis
 Inflammation of the urethra
 Caused by bacteria, viruses or chemicals
 Symptoms: painful urination, redness, itching at
meatus, ?discharge
 Treatment: sitz baths or warm compresses,
antibiotics, increased fluid intake