Function of the urinary system:

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Function of the urinary system maintains blood
volume and concentration eliminates
urine Urine water and filtered solutes from
blood normal daily volume of 1000-2000
mL regulates BP - secretes enzyme Renin which
changes BV Urology science of the urinary
system Urinary System Anatomy
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Kidney
Ureter
Bladder
Urethra
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Renal Cortex
Nephron
Minor Calyx
Major Calyx
Renal Medulla
Ureter
Renal Pelvis
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Nephron the functional unit of the
kidney Nephrons function by 1. Glomerular
Filtration (Renal Corpuscle) - forcing of
fluids from blood through a membrane using
pressure (importance of BP)
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Bowmans Capsule
Glomerulus
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2. Tubular Re-absorption (proximal /
distal convoluted tubules and loop of
Henle) -convoluted tubulessimple cuboidal w/
microvilli -about 99 of filtrate is
returned to blood -most re-absorption is
completed in the proximal convoluted
tubule -Loop of Henle little to no
reabsorption of H2O some reabsorption
of Na and Cl-
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3. Tubular Secretion - solutes and buffers
(maintain blood pH) are put back into urine
flow to be excreted. - Urine components CO2,
ammonia, urea, biliruben, uric acid, Na,
Cl-, sulfates, creatine Water Reabsorption is
controlled by Na and ADH ADH antidiuretic
hormone high ADH high water reabsorption low
urine water low ADH low water reabsorption
high urine water
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Excretory Organs Kidneys, Lungs, Skin,
Alimentary Canal, Liver Urine Volume is
determined by blood pressure BP can effect
diffusion of solutes low BP reabsorb
H2O and salts low urine volume blood
concentration amount of water in blood can
effect diffusion temperature diuretics
inhibit Na re-absorption or inhibit ADH
secretion emotions
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Abnormal conditions associated with urine
are glycosuria excess glucose in
urine common cause is diabetes
mellitus hematuria RBC in urine (inflammation
of urinary organs, tumors, disease) pyuria
WBC in urine and pus (infection of kidney or
other urinary organs) ketosis high levels
of ketones (indicate diabetes mellitus,
anorexia, starvation, or too little carbs in
diet) bilirubinuria high levels of biliruben
(may mean a high rate of RBC
destruction) casts tiny masses of material
which have hardened and assumed shape of tubule
in which they are formed calculi (kidney stone)
crystalized salts or other material
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Micturition (urination) results from both
voluntary and involuntary nerve impulses
(reflex arc) Incontinence a lack of control
over micturition causes injury to spinal cord
or nerves irritation due to abnormal
constituents in urine disease of
bladder damage to urethral sphincter inability
of destusor muscle to relax due to emotional
stress