What are the functions of the urinary system?

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Urinary System
What are the functions of the urinary
system? Osmoregulation water and salts Waste
excretion metabolic wastes (N) If water is
plentiful then NH3 If water is limited then
Urea If water is scarce then Uric acid Hormone
production blood cell formation as a result of
erythropoeitin secretion.
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Urinary System
What are the rules of thumb regarding water and
salts for different classes of vertebrates? Fresh
water organisms excrete water and conserve
salt Salt water organisms excrete salt and
conserve water Terrestrial organisms modify
salt and water loss appropriately
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Urinary System
What is the basic pattern and what is an
archinephros? Nephron functional unit of
kidneys Renal corpuscle 1) Glomerulus 2) Renal
tubules 3) Excretory ducts
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Urinary System
What is the basic pattern and what is an
archinephros? Nephron functional unit of
kidneys Renal corpuscle
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Urinary System
What are the 3 basic processes involved with
urine formation? 1) Filtration glomerulus 2)
Reabsorption renal tubules 3) Secretion renal
tubules Other processes include 4)
Concentration renal tubules and collecting
ducts 5) Storage bladder 6) Micturition
bladder, sphincters urethra
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Urinary System
Where does filtration take place?
Renal corpuscle glomerulus Bowmans capsule
Bowmans capsule parietal and visceral layers
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Urinary System
What is involved with producing filtrate?
Filtration Pressure Flow depends on
pressure Fluids and solutes move from gt press. to
lt press. Why is there a difference in pressure?
GCP Glomerular capillary pressure CP Capsule
pressure COP Colloidal osmotic pressure
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Urinary System
What is the route of blood flow through the
kidney and how does this fit with REABSORPTION?
Afferent arteriole to glomerulus to Efferent
arteriole to peritubular capillaries to vasa
recta, then back out
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Urinary System
What is the role of secretion in urine production?
Moving wastes into nephron both passive and
active Passive (NH3) Active / countertransport
(ex. H, K, Penicillin)
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Urinary System
How is urine concentrated?
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Urinary System
How do kidneys form embryologically? Nephrogenic
mesoderm lateral to mesodermal somites Where
are the kidneys in Necturus? Tubules appear at
cephalic end Paired ducts develop and form caudad
until they reach posterior and form
opening Posterior tubules
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Urinary System
What is an archinephros? Hypothetical kidney
Believed to be the prototype from a segmented
ancestor
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Urinary System
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Urinary System
Why would glomeruli be larger in freshwater fish
and aquatic amphibians and smaller in marine
fishes and tetrapods (especially in tetrapods of
arid environments)?
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Urinary System
How are kidneys organized?
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Urinary System
Where can one find a kidney?
LocationSmall of your back Sizefist-sized Surr
ounded byconnective tissue (renal
capsule) Protected byrenal fat pad (perirenal
fat)
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Urinary System
Gross anatomy!
retroperitoneal
peritoneal cavity
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Urinary System
What is extrarenal salt excretion and how does it
occur? Gills actively transport across
lamellar membranes Salt glands can empty into
nasal canals or mouth
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NGS/Shared/StaticFiles/animals/images/primary/mari
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What other anatomy is significant?
Transitional epithelium lines the ureters
urinary bladder
Stratified Stretchy
Contract peristaltic movements
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What other anatomy is significant?
Transitional epithelium lines the ureters
urinary bladder
Stratified Stretchy
Contract peristaltic movements