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The Urinary System
Chapter
15
Urinary System
Well, I guess you
don’t have kidney
stones after all.
Moment of Zen
KIDNEY
kidneys
Organs
of the
Urinary
System
ureters
urinary
bladder
urethra
7
8
Urinary System Organs
9
Figure 25.1a
10
Functions of the Urinary System

Elimination of waste products



Nitrogenous wastes
Toxins
Drugs
Functions of the Urinary System

Regulate aspects of homeostasis






Water balance
Electrolytes
Acid-base balance in the blood
Blood pressure
Red blood cell production
Activation of vitamin D
nephron
renal artery
renal vein
Kidney
Anatomy
Organs of the Urinary system




Kidneys
Ureters
Urinary bladder
Urethra
Figure 15.1a
Location of the Kidneys





Against the dorsal body wall
At the level of T12 to L3
The right kidney is slightly lower than
the left
Attached to ureters, renal blood
vessels, and nerves at renal hilus
Atop each kidney is an adrenal gland
Coverings of the Kidneys

Renal capsule


Surrounds each kidney
Adipose capsule



Surrounds the kidney
Provides protection to the kidney
Helps keep the kidney in its correct
location
Kidney
Anatomy
renal
pelvis
ureter
renal
pyramids
renal
cortex
renal
capsule
renal
medulla
Regions of the Kidney



Renal cortex –
outer region
Renal medulla
– inside the
cortex
Renal pelvis –
inner collecting
tube
Figure 15.2b
Kidney Structures



Medullary pyramids – triangular
regions of tissue in the medulla
Renal columns – extensions of cortexlike material inward
Calyces – cup-shaped structures that
funnel urine towards the renal pelvis
Blood Flow in the Kidneys
Figure 15.2c
Nephrons



The structural and functional units of
the kidneys
Responsible for forming urine
Main structures of the nephrons


Glomerulus
Renal tubule
Types of Nephrons

Cortical nephrons


Located entirely in the cortex
Includes most nephrons
Figure 15.3a
Types of Nephrons

Juxtamedullary nephrons

Found at the boundary of the cortex and
medulla
Figure 15.3a
Nephrons are connected to renal artery/vein and
ureter.
26
Nephron
Glomerulus


A specialized
capillary bed
Attached to
arterioles on both
sides (maintains
high pressure)


Large afferent
arteriole
Narrow efferent
arteriole
Figure 15.3c
Glomerulus


Capillaries are
covered with
podocytes from
the renal tubule
The glomerulus
sits within a
glomerular capsule
(the first part of the
renal tubule)
Figure 15.3c
30
31
Renal Tubule




Glomerular
(Bowman’s) capsule
Proximal
convoluted tubule
Loop of Henle
Distal convoluted
tubule
Figure 15.3b
Peritubular Capillaries





Arise from efferent arteriole of the
glomerulus
Normal, low pressure capillaries
Attached to a venule
Cling close to the renal tubule
Reabsorb (reclaim) some substances
from collecting tubes
Urine Formation Processes



Filtration
Reabsorption
Secretion
Figure 15.4
blood
filtration
General
Functioning
of the Kidney
tubular
reabsorption
and secretion
urine “refreshed” blood
Filtration




Nonselective passive process
Water and solutes smaller than
proteins are forced through capillary
walls
Blood cells cannot pass out to the
capillaries
Filtrate is collected in the glomerular
capsule and leaves via the renal tubule
Reabsorption



The peritubular capillaries reabsorb several
materials
 Some water
 Glucose
 Amino acids
 Ions
Some reabsorption is passive, most is active
Most reabsorption occurs in the proximal
convoluted tubule
Materials Not Reabsorbed

Nitrogenous waste products




Urea
Uric acid
Creatinine
Excess water
Secretion – Reabsorption in
Reverse

Some materials move from the
peritubular capillaries into the renal
tubules



Hydrogen and potassium ions
Creatinine
Materials left in the renal tubule move
toward the ureter
Formation of Urine
Figure 15.5
Characteristics of Urine Used for
Medical Diagnosis





Colored somewhat yellow due to the
pigment urochrome (from the
destruction of hemoglobin) and
solutes
Sterile
Slightly aromatic
Normal pH of around 6
Specific gravity of 1.001 to 1.035
Ureters

Slender tubes attaching the kidney to
the bladder




Continuous with the renal pelvis
Enter the posterior aspect of the bladder
Runs behind the peritoneum
Peristalsis aids gravity in urine
transport
43
15
The Urinary System
PART A
PowerPoint® Lecture Slide Presentation by Jerry L. Cook, Sam Houston University
ESSENTIALS
OF HUMAN
ANATOMY
& PHYSIOLOGY
EIGHTH EDITION
ELAINE N. MARIEB
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Urinary Bladder


Smooth, collapsible, muscular sac
Temporarily stores urine
Figure 15.6
Urinary Bladder

Trigone – three openings


Two from the ureters
One to the urethrea
Figure 15.6
Urinary Bladder Wall




Three layers of smooth muscle
(detrusor muscle)
Mucosa made of transitional epithelium
Walls are thick and folded in an empty
bladder
Bladder can expand significantly
without increasing internal pressure
Urethra


Thin-walled tube that carries urine from
the bladder to the outside of the body
by peristalsis
Release of urine is controlled by two
sphincters


Internal urethral sphincter (involuntary)
External urethral sphincter (voluntary)
Urethra Gender Differences

Length



Females – 3–4 cm (1 inch)
Males – 20 cm (8 inches)
Location


Females – along wall of the vagina
Males – through the prostate and penis
Urethra Gender Differences

Function


Females – only carries urine
Males – carries urine and is a passageway
for sperm cells
Micturition (Voiding)

Both sphincter muscles must open to
allow voiding



The internal urethral sphincter is relaxed
after stretching of the bladder
Activation is from an impulse sent to the
spinal cord and then back via the pelvic
splanchnic nerves
The external urethral sphincter must be
voluntarily relaxed
efferent
arteriole
afferent
arteriole
Glomerular
Filtration
Bowman’s
capsule
Filters blood; proteins can’t pass through
glomerulus
Urinary Bladder
ureters
external
sphincters
internal
sphincters
urethra
55
Maintaining Water Balance

Normal amount of water in the human
body





Young adult females – 50%
Young adult males – 60%
Babies – 75%
Old age – 45%
Water is necessary for many body
functions and levels must be maintained
Maintaining Water Balance



Water intake must equal water output
Sources for water intake
 Ingested foods and fluids
 Water produced from metabolic
processes
Sources for water output
 Vaporization out of the lungs
 Lost in perspiration
 Leaves the body in the feces
 Urine production
Maintaining Water Balance



Dilute urine is produced if water intake
is excessive
Less urine (concentrated) is produced
if large amounts of water are lost
Proper concentrations of various
electrolytes must be present
Distribution of Body Fluid


Intracellular fluid
(inside cells)
Extracellular fluid
(outside cells)


Interstitial fluid
Blood plasma
Figure 15.8
The Link Between Water and Salt

Changes in electrolyte balance causes
water to move from one compartment
to another


Alters blood volume and blood pressure
Can impair the activity of cells
Regulation of Water and Electrolyte
Reabsorption

Regulation is primarily by hormones


Antidiuretic hormone (ADH) prevents
excessive water loss in urine
Aldosterone regulates sodium ion
content of extracellular fluid


Triggered by the rennin-angiotensin
mechanism
Cells in the kidneys and
hypothalamus are active monitors
Maintaining Water and Electrolyte
Balance
Figure 15.10
Maintaining Acid-Base Balance in
Blood

Blood pH must remain between 7.35
and 7.45 to maintain homeostasis



Alkalosis – pH above 7.45
Acidosis – pH below 7.35
Most ions originate as byproducts of
cellular metabolism
Maintaining Acid-Base Balance in
Blood


Most acid-base balance is maintained
by the kidneys
Other acid-base controlling systems


Blood buffers
Respiration
Blood Buffers


Molecules react to prevent dramatic
changes in hydrogen ion (H+)
concentrations
 Bind to H+ when pH drops
 Release H+ when pH rises
Three major chemical buffer systems
 Bicarbonate buffer system
 Phosphate buffer system
 Protein buffer system
The Bicarbonate Buffer System



Mixture of carbonic acid (H2CO3) and
sodium bicarbonate (NaHCO3)
Bicarbonate ions (HCO3–) react with
strong acids to change them to weak
acids
Carbonic acid dissociates in the
presence of a strong base to form a
weak base and water
Respiratory System Controls of
Acid-Base Balance


Carbon dioxide in the blood is
converted to bicarbonate ion and
transported in the plasma
Increases in hydrogen ion
concentration produces more
carbonic acid
Respiratory System Controls of
Acid-Base Balance


Excess hydrogen ion can be blown off
with the release of carbon dioxide
from the lungs
Respiratory rate can rise and fall
depending on changing blood pH
Renal Mechanisms of Acid-Base
Balance



Excrete bicarbonate ions if needed
Conserve or generate new bicarbonate
ions if needed
Urine pH varies from 4.5 to 8.0
Developmental Aspects of the
Urinary System


Functional kidneys are developed by
the third month
Urinary system of a newborn


Bladder is small
Urine cannot be concentrated
Developmental Aspects of the
Urinary System


Control of the voluntary urethral
sphincter does not start until age 18
months
Urinary infections are the only
common problems before old age
Aging and the Urinary System



There is a progressive decline in
urinary function
The bladder shrinks with aging
Urinary retention is common in males
Urinalysis



Ancient Greeks & Roman physicians
routinely studied urine when diagnosing
patients
Today a urinalysis is done to check for
microorganism content, as well as
chemical and physical properties
Physical characteristics routinely checked:
color, turbidity, pH & specific gravity
Urinalysis




Healthy urine is sterile
bacteria can enter sample from 1)
incorrect sample collection or 2) infection
Infection can also be caused by fungus or
protozoans
Electrolytes in urine have clinical
implications – Ca2+, Cl-,K+, Na+
77
78
Three congenital abnormalities
results

Renal agenesis: failure of one or both kidneys to
develop



Duplications of urinary tract



Bilateral: rare, associated with other congenital
anomalies, incompatible with life
Unilateral: common, asymptomatic; other kidney
enlarges to compensate
Complete duplication: formation of extra ureter and renal
pelvis
Incomplete duplication: only upper part of excretory
system is duplicated
Malposition: one or both kidneys, associated with
fusion of kidneys; horseshoe kidney; fusion of
upper pole
Common congenital abnormalities of kidneys
and urinary tract
Glomerulonephritis


Inflammation of the glomeruli caused by antigenantibody reaction within the glomeruli
Immune-complex glomerulonephritis






Usually follows a beta-streptococcal infection
Circulating antigen and antibody complexes are filtered
by glomeruli and incite inflammation
Leukocytes release lysosomal enzymes that cause injury
to the glomeruli
Occurs in SLE; immune complexes trapped in glomeruli
Occurs in IgA nephropathy
Anti-glomerular basement membrane (anti-GBM)
glomerulonephritis: autoantibodies attack
glomerular basement membrane
Normal glomerulus
Immune complex glomerulonephritis
Anti-GBM glomerulonephritis
Nephrotic Syndrome (1 of 2)

Marked loss of protein in the urine




Urinary excretion of protein > protein production
Protein level in blood falls
Causes edema due to low plasma osmotic
pressure
Clinical manifestations


Marked leg edema
Ascites
Nephrotic Syndrome (2 of 2)

Prognosis



In children: minimal glomerular change, complete
recovery
In adults: a manifestation of severe progressive
renal disease
May result from




Glomerulonephritis
Diabetes (causing glomerular changes)
Systemic lupus erythematosus, SLE
Other kidney diseases
Arteriolar Nephrosclerosis



Complication of severe hypertension
Renal arterioles undergo thickening from carrying
blood at a much higher pressure than normal
Glomeruli and tubules undergo secondary
degenerative changes causing narrowing of
lumen and reduction in blood flow



Reduced glomerular filtration
Kidneys shrink
May die of renal insufficiency
Diabetic Nephropathy



Complication of long-standing diabetes
Nodular and diffuse thickening of glomerular
basement membranes (glomerulosclerosis),
usually with coexisting nephrosclerosis
Manifestations




Progressive impairment of renal function
Protein loss may lead to nephrotic syndrome
No specific treatment can arrest progression of
disease
Progressive impairment of renal function may lead to
renal failure
Diffuse glomerulosclerosis
Nodular glomerulosclerosis
Gout Nephropathy

Pathogenesis




Elevated blood uric acid levels lead to ↑uric
acid in tubular filtrate
Urate may precipitate in Henle’s loops and
collecting tubules
Tubular obstruction causes damage
Manifestations



Impaired renal function
May lead to renal failure
Common in poorly-controlled gout
Urate nephropathy showing multiple
depressed scars
Section of kidney revealing white urate deposits within
renal pyramid and large urate deposit near tip of
pyramid
Urinary Tract Infections (1 of 2)




Very common; maybe acute or chronic
Most infections are caused by gram-negative
bacteria
Organisms contaminate perianal and genital areas
and ascend urethra
Conditions protective against infection




Free urine flow
Large urine volume
Complete bladder emptying
Acid urine: most bacteria grow poorly in an acidic
environment
Urinary Tract Infections (2 of 2)

Predisposing factors




Any condition that impairs free drainage of urine
Stagnation of urine favors bacterial growth
Injury to mucosa by kidney stone disrupts protective
epithelium allowing bacteria to invade deeper tissue
Introduction of catheter or instruments into bladder
may carry bacteria
Cystitis

Affects only the bladder



More common in women than men; shorter female
urethra, and, in young sexually active women, sexual
intercourse promotes transfer of bacteria from urethra to
bladder
Common in older men, because enlarged prostate
interferes with complete bladder emptying
Clinical manifestations





Burning pain on urination
Desire to urinate frequently
Urine contains many bacteria and leukocytes
Responds well to antibiotics
May spread upward into renal pelvis and kidneys
Pyelonephritis

Involvement of upper urinary tract from



Ascending infection from the bladder (ascending
pyelonephritis)
Carried to the kidneys from the bloodstream
(hematogenous pyelonephritis)
Clinical manifestations: similar with an acute
infection




Localized pain and tenderness over affected kidney
Responds well to antibiotics
Cystitis and pyelonephritis are frequently associated
Some cases become chronic and lead to kidney failure
Vesicoureteral Reflux


Urine normally prevented from flowing back
into the ureters during urination
Failure of mechanisms allows bladder urine
to reflux into ureter during voiding


Predisposes to urinary tract infection
Predisposes to pyelonephritis
Vesicoureteral reflux
Urinary Calculi (1 of 3)


Stones may form anywhere in the urinary tract
Predisposing factors

High concentration of salts in urine saturates urine
causing salts to precipitate and form calculi




Uric acid in gout
Calcium salts in hyperparathyroidism
Urinary tract infections reduce solubility of salts in urine;
clusters of bacteria are sites where urinary salts may
crystallize to form stone
Urinary tract obstruction causes urine stagnation,
promotes stasis and infection, further increasing stone
formation
Urinary Calculi (2 of 3)




Staghorn calculus: urinary stones that increase in
size to form large branching structures that adopt
to the contour of the pelvis and calyces
Small stones may pass through ureters causing
renal colic
Some become impacted in the ureter and need to
be removed
Manifestations


Renal colic associated with passage of stone
Obstruction of urinary tract causes hydronephrosishydroureter proximal to obstruction
Urinary Calculi (3 of 3)

Treatment


Cystoscopy: snares and removes stones lodged
in distal ureter
Shock wave lithotripsy: stones lodged in
proximal ureter are broken into fragments that
are readily excreted
Large staghorn calculus of kidney
Urinary Obstruction


Blockage of urine outflow leads to progressive
dilatation of urinary tract proximal to obstruction,
eventually causes compression atrophy of
kidneys
Manifestations



Causes




Hydroureter: dilatation of ureter
Hydronephrosis: dilatation of pelvis and calyces
Bilateral: obstruction of bladder neck by enlarged
prostate or urethral stricture
Unilateral: ureteral stricture, calculus, tumor
Complications: stone formation; infections
Diagnosis and treatment: pyelogram, CT san
Possible locations and results of urinary tract
obstruction
Marked hydronephrosis and hydroureter
Bisected hydronephrotic kidney
Foreign Bodies in Urinary
Tract




Usually inserted by patient
May injure bladder
Predispose to infection
Treatment


Usually removed by cystoscopy
Occasionally necessary to open bladder
surgically
X-ray film illustrating foreign body in bladder.
Renal Tubular Injury

Pathogenesis



Impaired renal blood flow
Tubular necrosis caused by toxic drugs or
chemicals
Clinical manifestation



Acute renal failure: oliguria, anuria
Tubular function gradually recovers
Treated by dialysis until function returns
Renal Cysts


Solitary cysts common; not associated with
impairment of renal function
Multiple cysts







Congenital polycystic kidney disease
Most common cause of multiple cysts
Mendelian dominant transmission
Cysts enlarge and destroy renal tissue and function
Onset of renal failure by late middle age
Suspected by physical examination that reveals greatly
enlarged kidneys
Some form cysts in liver or cerebral aneurysm
Renal Tumors

Cortical tumors: arise from epithelium of renal
tubules






Adenomas: usually small and asymptomatic
Carcinomas more common
Hematuria often first manifestation
Invades renal vein and metastasizes into bloodstream
Treated by nephrectomy
Transitional cell tumor: Arise from transitional
epithelium lining urinary tract



Most arise from bladder epithelium
Hematuria: common first manifestation
Low grade malignancy; good prognosis
Nephroblastoma (Wilms Tumor)


Uncommon; highly malignant; affects infants
and children
Diagnosis







Urinalysis
Urine culture and sensitivity tests
Blood chemistry tests
Clearance tests
X-ray, ultrasound, cystoscopy
Renal biopsy
Treatment: nephrectomy; radiotherapy;
chemotherapy
Renal Failure (Uremia) (1 of 2)


Retention of excessive byproducts of protein
metabolism in the blood
Acute renal failure



Causes: tubular necrosis from impaired blood flow to
kidneys or effects of toxic drugs
Renal function usually returns
Chronic renal failure


From progressive, chronic kidney disease; > 50% from
chronic glomerulonephritis
Others include congenital polycystic kidney disease,
nephrosclerosis, diabetic nephropathy
Renal Failure (Uremia) (2 of 2)

Clinical manifestations






Weakness, loss of appetite, nausea, vomiting
Anemia
Toxic manifestations from retained waste
products
Edema: retention of salt and water
Hypertension
Treatment


Hemodialysis
Hypertension
Hemodialysis



Substitutes for the functions of the kidneys by
removing waste products from patient’s blood
Waste products in patient’s blood diffuse across a
semipermeable membrane into a solution
(dialysate) into the other side of the membrane
Two types


Extracorporeal dialysis (more common): patient’s
circulation connected to an artificial kidney machine
Peritoneal dialysis (less common): patient’s own
peritoneum is used as the dialyzing membrane
Function
1. Remove nitrogenous wastes
2. Maintain electrolyte, acid-base,
and fluid balance of blood
3. Homeostatic organ
4. Acts as blood filter
5. Release hormones: calcitriol &
erythropoietin
Kidneys as Filters
• Diuretic- loose water; coffee, alcohol
• Antidiuretic- retain water; ADH
• Aldosterone- sodium & water reabsorption,
and K+ excretion
• GFR= 180 liters (50 gal) of blood/day
• 178-179 liters are reabsorbed back into
blood
• Excrete a protein free filtrate
Maintaining
Chemical
Homeostasis
The
Urinary
System
The Urinary System
Nitrogenous
Wastes
urea
uric acid
ammonia
efferent
arteriole
afferent
arteriole
glomerulus
artery
peritubular
capillaries
loop of
Henle
vein
Bowman’s
capsule
proximal
convoluted
tubule
distal
convoluted
tubule
collecting
duct
Each kidney contains over 1 million nephrons and thousands
of collecting ducts
Glomerulus
DCT
renal
cortex
PCT
renal
medulla
Collecting duct
Loop of Henle
Composition of
Glomerular Filtrate
• Water
• Small Soluble Organic
Molecules
• Mineral Ions
Proximal Convoluted
Tubule
Reabsorbs: water, glucose,
amino acids, and sodium.
•
•
•
•
65% of Na+ is reabsorbed
65% of H2O is reabsorbed
90% of filtered bicarbonate (HCO3-)
50% of Cl- and K+
Loop of Henle
Creates a gradient of increasing
sodium ion concentration towards
the end of the loop within the
interstitial fluid of the renal pyramid.
• 25% Na+ is reabsorbed in the loop
• 15% water is reabsorbed in the loop
• 40% K is reabsorbed in the loop
Distal Convoluted
Tubule
Under the influence of the hormone
aldosterone, reabsorbs sodium and
secretes potassium. Also regulates
pH by secreting hydrogen ion when
pH of the plasma is low.
• only 10% of the filtered NaCl and 20% of water
remains
Collecting Duct
Allows for the osmotic
reabsorption of water.
ADH (antidiuretic hormone)- makes
collecting ducts more permeable to
water-- produce concentrated urine
Urine
Water- 95%
Nitrogenous waste:
• urea
• uric acid
• creatinine
Ions:
• sodium
• potassium
• sulfate
• phosphate
From the original 1800 g NaCl, only 10 g appears in
the urine
Hormonal
Control of
Kidney
Function
Hormonal Control
of Kidney Function
high plasma
solute
concentration
low blood volume
heart receptors
hypothalamus
Hormonal Control
of Kidney Function
hypothalamus
posterior pituitary
antidiuretic hormone
collecting ducts
Hormonal
Control of
Kidney
Function
Hormonal Control
of Kidney Function
reduced blood pressure and
glomerular filtrate
juxtaglomerular apparatus
renin
Hormonal Control
of Kidney Function
angiotensinogen
angiotensin I
angiotensin II
renin
Hormonal Control
of Kidney Function
angiotensin II
adrenal cortex
aldosterone
convoluted tubules
Bladder
1. Mucosa (transitional epithelium)
2. Muscular layer (detrusor muscle):
3 layers of smooth muscle
3. Fibrous adventia
Sphincter Muscles on Bladder
Internal urethral sphincter:
• Smooth muscle
• Involuntary control
• More superiorly located
External Urethral sphincter:
• Skeletal muscle
• Voluntary control
• Posteriorly located
Diuresis (Micturition)
When bladder fills with 200 ml of urine,
stretch receptors transmit impulses to
the CNS and produce a reflex
contraction of the bladder (PNS)
When is incontinence normal?
Distension
of the
Urinary
Bladder
Urinalysis
Why do doctors ask for a urine sample?
characteristics:
• smell- ammonia-like
• pH- 4.5-8, ave 6.0
• specific gravity– more than 1.0; ~1.0011.003
• color- affected by what we eat: salty foods,
vitamins
Odor
odor- normal is ammonia-like
diabetes mellitus- smells fruity or
acetone like due to elevated ketone
levels
diabetes insupidus- yucky
asparagus---
pH- range 4.5-8 ave 6.0
vegetarian diet- urine is alkaline
protein rich and wheat dieturine is acidic
Color
Color- pigment is urochrome
Yellow color due to metabolic breakdown of
hemoglobin (by bile or bile pigments)
Beets or rhubarb- might give a urine pink or
smoky color
Vitamins- vitamin C- bright yellow
Infection- cloudy
Specific Gravity
Water: s.g. = 1g/liter;
Urine: s.g. ~ 1.001 to 1.030
Pyelonephritus- urine has high s.g.;
form kidney stones
Diabetes insipidus- urine has low
s.g.; drinks excessive water; injury or
tumor in pituitary
Abnormal Constitutes of Urine
Glucose- when present in urine condition
called glycosuria (nonpathological)
[glucose not normally found in urine]
Indicative of:
• Excessive carbohydrate intake
• Stress
• Diabetes mellitus
Abnormal Constitutes of Urine
Albumin-abnormal in urine; it’s a very large
molecule, too large to pass through glomerular
membrane > abnormal increase in permeability
of membrane
Albuminuria- nonpathological conditionsexcessive exertion, pregnancy, overabundant
protein intake-- leads to physiologic albuminuria
Pathological condition- kidney trauma due to
blows, heavy metals, bacterial toxin
Abnormal Constitutes of Urine
Ketone bodies- normal in urine but in small amts
Ketonuria- find during starvation, using fat stores
Ketonuria is couples w/a finding of glycosuria-- which
is usually diagnosed as diabetes mellitus
RBC-hematuria
HemoglobinHemoglobinuria- due to fragmentation or hemolysis of
RBC; conditions: hemolytic anemia, transfusion
reaction, burns or renal disease
Abnormal Constitutes of Urine
Bile pigmentsBilirubinuria (bile pigment in urine)- liver pathology such as
hepatitis or cirrhosis
WBCPyuria- urinary tract infection; indicates inflammation of
urinary tract
Casts- hardened cell fragments, cylindrical, flushed out of
urinary tract
WBC casts- pyelonephritus
RBC casts- glomerulonephritus
Fatty casts- renal damage
INQUIRY
1.
2.
3.
4.
5.
List several functions of the kidneys.
What does the glomerulus do?
What are several constitutes you should not find in urine?
What is specific gravity?
What two hormones effect fluid volume and sodium
concentration in the urine?
6. Where are the pyramids located in the kidney?
7. What vessel directs blood into the glomerulus?
8. Where does most selective reabsorption occur in the
nephron?