The Urinary System

The Urinary System

•Kidneys, ureters, urinary bladder & urethra

• Urine flows from each kidney, down its ureter to the bladder and to the outside via the urethra

• Filter the blood and return most of water and solutes to the bloodstream

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Organs of the

Urinary System

Organs of the

Urinary System

kidneys

ureters

urinary bladder

urethra

کلیههاعضوپشتصفاقیازمهره،دوازدهمپشتیتاسومیناندشدهواقعکمریمهره

شریانکلیویازآئورتشکمیووریدکلیوینیزبهوریداجوریزدمیتحتانیف

اعصابمثانهسمپاتیکوپاراسمپاتیکدفعادراردقیقترینراهاندازهگیریفیلتراسیونگلومرولیکلیرانس

استساعتهادرارتوسطکراتینین

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Urinary systemUrinary system

• Organ system that produces, stores, and carries urine• Includes two kidneys, two ureters, the urinary bladder, two

sphincter muscles, and the urethra. • Humans produce about 1.5 liters of urine over 24 hours,

although this amount may vary according to the circumstances. • Increased fluid intake generally increases urine production.• Increased perspiration and respiration may decrease the amount

of fluid excreted through the kidneys. • Some medications interfere directly or indirectly with urine

production, such as diuretics.

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Function

1. Remove nitrogenous wastes2. Maintain electrolyte, acid-base,

and fluid balance of blood3. Homeostatic organ4. Acts as blood filter5. 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 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

urine

blood

filtration

tubular reabsorption and secretion

General Functioning of

the Kidney

General Functioning of

the Kidney

“refreshed” blood

renal capsule

renal cortex

renal medulla

renal pelvis

renal pyramids

ureter

Kidney AnatomyKidney

Anatomy

Kidney AnatomyKidney

Anatomy

renal artery

renal vein

nephronnephron

urine

blood

filtration

tubular reabsorption and secretion

Nephron Functioning

Nephron Functioning

“refreshed” blood

vein

artery

afferent arteriole

efferent arteriole

glomerulus

peritubular capillaries

Bowman’s capsule

proximal convoluted tubuledistal convoluted tubule

loop of Henle

collecting duct

renal cortex

renal medulla

Each kidney contains over 1 million nephrons and thousands of collecting ducts

Collecting duct

Loop of Henle

PCT

DCTGlomerulus

Glomerular Filtration

Glomerular Filtration

afferent arteriole

glomerulus

efferent arteriole

Bowman’s capsule

Filters blood; proteins can’t pass through

Composition of Glomerular Filtrate

• WaterWater• Small Soluble Organic Small Soluble Organic

MoleculesMolecules• Mineral IonsMineral Ions

Proximal Convoluted Tubule

Reabsorbs: water, glucose, Reabsorbs: water, glucose, amino acids, and sodium.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 Creates a gradient of increasing sodium ion concentration towards sodium ion concentration towards the end of the loop within the the end of the loop within the interstitial fluid of the renal pyramid.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 Under the influence of the hormone aldosterone, reabsorbs sodium and aldosterone, reabsorbs sodium and secretes potassium. Also regulates secretes potassium. Also regulates pH by secreting hydrogen ion when pH by secreting hydrogen ion when pH of the plasma is low.pH of the plasma is low.

• only 10% of the filtered NaCl and 20% of water remains

Collecting Duct

Allows for the osmotic Allows for the osmotic reabsorption of water.reabsorption of water.

ADH (antidiuretic hormone)- makes collecting ducts more permeable to water-- produce concentrated urine

From the original 1800 g NaCl, only 10 g appears in the urine

Urine

Water- 95%Nitrogenous waste:

• urea• uric acid• creatinine

Ions:• sodium• potassium• sulfate• phosphate

Hormonal Control of

Kidney Function

Hormonal Control of Kidney Function

low blood volumelow blood volumehigh plasma high plasma solute solute

concentrationconcentration

hypothalamushypothalamus

heart receptorsheart receptors

Hormonal Control of Kidney Function

hypothalamushypothalamus

posterior pituitaryposterior pituitary

antidiuretic hormoneantidiuretic hormone

collecting ductscollecting ducts

Hormonal Control of

Kidney Function

Hormonal Control of Kidney Function

reduced blood pressure and reduced blood pressure and glomerular filtrateglomerular filtrate

juxtaglomerular apparatusjuxtaglomerular apparatus

reninrenin

Hormonal Control of Kidney Function

reninreninangiotensinogenangiotensinogen

angiotensin Iangiotensin I

angiotensin IIangiotensin II

Hormonal Control of Kidney Function

adrenal cortexadrenal cortex

aldosteronealdosterone

angiotensin IIangiotensin II

convoluted tubulesconvoluted tubules

Urinary BladderUrinary Bladder

uretersinternal sphinctersexternal

sphinctersurethra

Bladder

1. Mucosa (transitional epithelium)2. Muscular layer (detrusor muscle):

3 layers of smooth muscle3. Fibrous adventia

Internal urethral sphincter:• Smooth muscle• Involuntary control• More superiorly located

External Urethral sphincter:• Skeletal muscle• Voluntary control• Posteriorly located

Sphincter Muscles on Bladder

When bladder fills with 200 ml of urine, stretch receptors transmit impulses to the CNS and produce a reflex contraction of the bladder (PNS)

Diuresis (Micturition)

When is incontinence normal?

Distension of the Urinary

Bladder

Why do doctors ask for a urine sample?       

Urinalysis

characteristics:• smell- ammonia-like• pH- 4.5-8, ave 6.0• specific gravity– more than 1.0; ~1.001-

1.003 • color- affected by what we eat: salty foods,

vitamins

odor- normal is ammonia-like

diabetes mellitus- smells fruity or acetone like due to elevated ketone levels

diabetes insupidus- yucky

asparagus---

Odor

pH- range 4.5-8 ave 6.0

vegetarian diet- urine is alkaline

protein rich and wheat diet- urine is acidic

Color- pigment is urochromeYellow 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

Color

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

Specific Gravity

 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 conditions- excessive 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

Hemoglobin-

Hemoglobinuria- due to fragmentation or hemolysis of RBC; conditions: hemolytic anemia, transfusion reaction, burns or renal disease

Abnormal Constitutes of Urine

Bile pigments-

Bilirubinuria (bile pigment in urine)- liver pathology such as hepatitis or cirrhosis

WBC-

Pyuria- 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

Abnormal Constitutes of Urine

Uc :از کمتر طبیعی =1000اگر کولونیمشکوک=10000کمتراز کولونی

عفونی=100000باالی کولونیماده کلیرانس: تقسیم Aغلظت معین ادراردرزمان حجم ضربدر درادرار

ماده غلظت درپالسماAبرResidual urine

KUBIVP کرچک روغن با روده ،تخلیه مایعات مصرف عدم

رتروگراد پیلوگرافیCTS

سیستویورتروگرافیکلیه آنژیوگرافی

اولتراسونوگرافیایزوتوپ رادیو بررسی

کلیه بیوپسیسیستوسکوپینفروسکوپی

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