Post on 12-May-2015
Urinary System Urinary System Anatomy and Anatomy and PhysiologyPhysiology
Part IPart I
Urinary SystemUrinary System Kidneys (2)Kidneys (2)
Most important excretory organMost important excretory organ Eliminate wasteEliminate waste
Ureters (2)Ureters (2) Bladder (1)Bladder (1) Urethra (1)Urethra (1) Nephron UnitNephron Unit
Functional unit of the kidneyFunctional unit of the kidney Formation of urineFormation of urine Tubular and vascular structuresTubular and vascular structures
Kidney Location and Kidney Location and ProtectionProtection
Kidneys are located in the posterior Kidneys are located in the posterior wall of the abdominal cavitywall of the abdominal cavity
In the In the retroperitonealretroperitoneal space space Connective tissue (renal fascia) hold Connective tissue (renal fascia) hold
the kidneys in placethe kidneys in place Adipose tissue cushion the kidneysAdipose tissue cushion the kidneys The lower rib cage partially enclose The lower rib cage partially enclose
the kidney and protect themthe kidney and protect them
Urinary System – Urinary System – Anterior/Posterior ViewsAnterior/Posterior Views
Kidney StructuresKidney Structures
Kidney is reddish-brownKidney is reddish-brown Looks like a beanLooks like a bean Approximately 4 inches x 2 inchesApproximately 4 inches x 2 inches Hilus – indentation where blood Hilus – indentation where blood
vessels and structures enter or exit vessels and structures enter or exit the kidneythe kidney
Three RegionsThree Regions in the kidney if sliced in the kidney if sliced in half – renal cortex, renal medulla, in half – renal cortex, renal medulla, renal pelvisrenal pelvis
Renal CortexRenal Cortex
Light, outside Light, outside regionregion
Cortex means Cortex means “bark”“bark”
Renal MedullaRenal Medulla
Dark, triangular Dark, triangular structurestructure
Form small cone Form small cone shaped regions shaped regions called called renal pyramids renal pyramids
Each pyramid is Each pyramid is separated by separated by renal renal columnscolumns
The lower ends of The lower ends of the pyramids point to the pyramids point to the renal pelvisthe renal pelvis
Renal pelvisRenal pelvis A basin that collects A basin that collects
the urine made by the the urine made by the kidney and helps form kidney and helps form the upper end of the the upper end of the ureterureter
The edges of the renal The edges of the renal pelvis closest to the pelvis closest to the renal pyramids are renal pyramids are called called calycescalyces
CalycesCalyces collect the collect the urine formed in the urine formed in the kidneykidney
How do they work?How do they work?
Need a blood supplyNeed a blood supply Brought to the kidney via the renal arteryBrought to the kidney via the renal artery Renal artery stems from the abdominal aortaRenal artery stems from the abdominal aorta 20-25% of cardiac output goes to the kidneys20-25% of cardiac output goes to the kidneys Smaller arteries supply blood to the nephron Smaller arteries supply blood to the nephron
unitunit Blood leaves the kidney via the renal veinsBlood leaves the kidney via the renal veins The renal veins empty into the inferior vena The renal veins empty into the inferior vena
cavacava
Functions of the KidneysFunctions of the Kidneys
Excrete nitrogenous waste from the bodyExcrete nitrogenous waste from the body UreaUrea AmmoniaAmmonia CreatinineCreatinine
Regulate blood volume Regulate blood volume Help regulate electrolyte content of the Help regulate electrolyte content of the
bloodblood Regulate acid-base balance (pH)Regulate acid-base balance (pH) Regulate blood pressureRegulate blood pressure Regulates red blood cell productionRegulates red blood cell production
The Formation of UrineThe Formation of Urine
The The Nephron UnitNephron Unit Each kidney contains about 1 million Each kidney contains about 1 million
nephron unitsnephron units The number does not increase after The number does not increase after
birthbirth They cannot be replaced if damagedThey cannot be replaced if damaged 2 parts2 parts
Tubular component (renal tubule)Tubular component (renal tubule) Vascular componentVascular component
Renal TubulesRenal Tubules
Glomerular capsule (Bowman’s Glomerular capsule (Bowman’s Capsule) – “C” shaped capsule Capsule) – “C” shaped capsule surrounding the glomerulussurrounding the glomerulus
Glomerulus – cluster of capillariesGlomerulus – cluster of capillaries Proximal convoluted tubuleProximal convoluted tubule Loop of Henle – ascending and Loop of Henle – ascending and
descending limbdescending limb Distal Convoluted tubuleDistal Convoluted tubule Collecting ductCollecting duct
NephronNephron
Renal VasculatureRenal Vasculature Receives blood from the renal arteryReceives blood from the renal artery Renal artery branches into the afferent arteriolesRenal artery branches into the afferent arterioles Afferent arterioles feed into Bowman’s capsuleAfferent arterioles feed into Bowman’s capsule The efferent arterioles exit Bowman’s capsuleThe efferent arterioles exit Bowman’s capsule The efferent arterioles form the peritubular The efferent arterioles form the peritubular
capillariescapillaries The peritubular capillaries empty into the The peritubular capillaries empty into the
venules, large veins, and then into the renal venules, large veins, and then into the renal veinsveins
It is imperative you know the relationship It is imperative you know the relationship between the tubular and vascular structures.between the tubular and vascular structures.
Urine FormationUrine Formation
Formed in the nephron unitFormed in the nephron unit Water and dissolved substances move Water and dissolved substances move
through the renal tubules and vesselsthrough the renal tubules and vessels Three processes are involved in urine Three processes are involved in urine
formationformation Glomerular filtrationGlomerular filtration Tubular reabsorptionTubular reabsorption Tubular secretionTubular secretion
Composition of UrineComposition of Urine
SterileSterile 95 % water95 % water Nitrogen containing waste – urea, uric Nitrogen containing waste – urea, uric
acid, ammonia, creatinineacid, ammonia, creatinine Electrolytes Electrolytes Light yellow color of urine is due to a Light yellow color of urine is due to a
pigment called urochromepigment called urochrome Urochrome is formed from the Urochrome is formed from the
breakdown of hemoglobin in the liverbreakdown of hemoglobin in the liver
Urine Specific GravityUrine Specific Gravity
Ratio of the amount of solute to the total Ratio of the amount of solute to the total volumevolume
Solute = substance dissolved in the urineSolute = substance dissolved in the urine The greater the solute = greater the The greater the solute = greater the
specific gravityspecific gravity Concentrated Urine = high specific gravityConcentrated Urine = high specific gravity
Ex. dehydrationEx. dehydration Dilute Urine = low specific gravityDilute Urine = low specific gravity
Ex. Overhydration, diabetes insipidusEx. Overhydration, diabetes insipidus
Urine CharacteristicsUrine Characteristics
Amount – 1500 ml in 24 hoursAmount – 1500 ml in 24 hours pH – average 6.0pH – average 6.0 Specific Gravity – heavier than water Specific Gravity – heavier than water
(1.001-1.035)(1.001-1.035) Color – yellow (amber, straw colored, Color – yellow (amber, straw colored,
concentrated, orange, brown, red, concentrated, orange, brown, red, sediment, clear or cloudy)sediment, clear or cloudy)
Dehydrated = deep yellow, darkDehydrated = deep yellow, dark Overhydrated = pale yellow, colorlessOverhydrated = pale yellow, colorless
Abnormal Abnormal Constituents Constituents of Urineof Urine
Albumin (protein)Albumin (protein) GlucoseGlucose Red blood cellsRed blood cells HemoglobinHemoglobin White blood cellsWhite blood cells Ketone bodiesKetone bodies BilirubinBilirubin
Urine TestingUrine Testing
UrinalysisUrinalysis Microscopic examMicroscopic exam Culture and sensitivityCulture and sensitivity Urine dipstickUrine dipstick Urine Drug and alcohol screeningUrine Drug and alcohol screening 24 hour urine testing24 hour urine testing
Your Plumbing – The Your Plumbing – The Urinary TractUrinary Tract
(Ureters, Urinary bladder, (Ureters, Urinary bladder, Urethra)Urethra) UretersUreters
Transport urine, they do not alter it Transport urine, they do not alter it in any wayin any way
Urine moves in response to gravity Urine moves in response to gravity and muscular movements called and muscular movements called peristalsis through ureters.peristalsis through ureters.
Your “Plumbing”Your “Plumbing”
The BladderThe Bladder Stores urine temporarily until eliminationStores urine temporarily until elimination Located behind the symphasis pubisLocated behind the symphasis pubis A distended bladder or full bladder can be palpated A distended bladder or full bladder can be palpated
above the syphasis in the abdominal cavity.above the syphasis in the abdominal cavity. Bladder has 4 layersBladder has 4 layers
Mucous membraneMucous membrane Submucosa Submucosa Detrusor muscle – involuntary smooth muscleDetrusor muscle – involuntary smooth muscle SerosaSerosa
Contain rugae to allow for stretchingContain rugae to allow for stretching Trigone – triangular area in the floor of the bladderTrigone – triangular area in the floor of the bladder
Urination – “Micturition”Urination – “Micturition” Expelling urine from the bladderExpelling urine from the bladder The urge to urinate (void) happened at about The urge to urinate (void) happened at about
200 ml of urine in the bladder200 ml of urine in the bladder At about 300 ml urine in the bladder, the urge At about 300 ml urine in the bladder, the urge
becomes more uncomfortablebecomes more uncomfortable Moderately full = 500 ml urineModerately full = 500 ml urine Overdistended bladder may have over 1000 ml Overdistended bladder may have over 1000 ml
urineurine Bacteria in your bladder doubles every 4 hours.Bacteria in your bladder doubles every 4 hours. Stimulated by stretch receptorsStimulated by stretch receptors
UrethraUrethra Carries urine from the bladder to the outside of Carries urine from the bladder to the outside of
the body the body Internal sphincter prevents urine from Internal sphincter prevents urine from
emptying; composed of smooth muscle; emptying; composed of smooth muscle; involuntaryinvoluntary
External sphincter at the upper portion of the External sphincter at the upper portion of the urethra allows you to resist the urge to urinate; urethra allows you to resist the urge to urinate; composed of skeletal muscle; voluntarycomposed of skeletal muscle; voluntary
Female – short, opens to the outside at the Female – short, opens to the outside at the urethral meatusurethral meatus
Male – longer, passes through the prostate Male – longer, passes through the prostate gland; carries urine and spermgland; carries urine and sperm
Urinary Retention and Urinary Retention and SuppressionSuppression
Retention - Inability to voidRetention - Inability to void Post operative; anesthesiaPost operative; anesthesia Bladder dysfunctionBladder dysfunction
Suppression – no urine formationSuppression – no urine formation Kidney dysfunctionKidney dysfunction
Data Collection & Data Collection & DocumentationDocumentation
Characteristics of urine Characteristics of urine ColorColor SedimentSediment Clear or cloudyClear or cloudy OdorOdor
How does the patient/resident void?How does the patient/resident void? Urinary diversions?Urinary diversions? Signs and symptomsSigns and symptoms
UrgencyUrgency FrequencyFrequency Burning sensationBurning sensation HesitancyHesitancy
What is the Costovertebral What is the Costovertebral Angle?Angle?
Costovertebral Angle
T12
T11
L1
12th Rib
R. Kidney L. Kidney
Region to assess for kidney tenderness
Disorders of the Urinary Disorders of the Urinary SystemSystem
GlomerulonephritisGlomerulonephritis Polycystic KidneyPolycystic Kidney PyelonephritisPyelonephritis Renal Calculi – kidney stonesRenal Calculi – kidney stones Renal FailureRenal Failure UTI – urinary tract infectionUTI – urinary tract infection
As We AgeAs We Age
By age 80 there is a 50% reduction in By age 80 there is a 50% reduction in nephron units; therefore a decreased nephron units; therefore a decreased ability to concentrate urineability to concentrate urine
Urinary bladder shrinks and becomes Urinary bladder shrinks and becomes less able to contract and relax; therefore less able to contract and relax; therefore the elderly must void frequentlythe elderly must void frequently
Bladder infection incidence increasesBladder infection incidence increases Increase in bladder incontinence due to Increase in bladder incontinence due to
weakened musclesweakened muscles