Urinary System
What are the functions of the urinary system?
**__________ – water and salts
____________
metabolic wastes (N)
If water is plentiful then NH3
If water is limited then Urea
If water is scarce then Uric acid
_______________ – blood cell
formation as a result of erythropoeitin secretion.
http://www.elitesavers.com/funny/peeing.jpg
Urinary System
What are the “rules of thumb”
regarding water and salts for
different classes of vertebrates?
____________________–
excrete water and conserve salt
_____________________–
excrete salt and conserve water
_____________________–
modify salt and water loss
appropriately
Urinary System
What is the basic pattern and
what is an archinephros?
___________ – functional
unit of kidneys
Renal corpuscle:
1) ____________
2) ____________
3) ____________
Urinary System
What is the basic pattern and
what is an archinephros?
Nephron – functional unit of
kidneys
Renal corpuscle –
Urinary System
What are the 3 basic processes involved with urine
formation?
1) ____________ – glomerulus
2) ____________ – renal tubules
3) ____________ – renal tubules
Other processes include:
4) ______________ – renal tubules and collecting
ducts
5) _____________ – bladder
6) ____________ – bladder, sphincters & urethra
Urinary System
Where does filtration take place?
Renal corpuscle =
Bowman’s capsule =
Urinary System
What is involved with producing filtrate?
Filtration Pressure…
Flow depends on …
Fluids and solutes move from …
Why is there a difference in
pressure?
GCP = Glomerular capillary pressure
CP = Capsule pressure
COP = Colloidal osmotic pressure
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
Urinary System
What is the role of secretion in urine production?
Moving wastes
into nephron
both passive and
active
Passive …
Active ….
Urinary System
How is urine concentrated?
Urinary System
How do kidneys form
embryologically?
_______________________–
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
Urinary System
What is an archinephros?
_______________–
Believed to be the
prototype from a
segmented ancestor
Urinary System
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)?
Urinary System
How are kidneys organized?
Urinary System
Where can one find a kidney?
Location:
Size:
Surrounded by
connective tissue
(_________________)
Protected by
renal fat pad (_____________)
Urinary System
Gross anatomy!
Urinary System
What is extrarenal salt excretion
and how does it occur?
________ – actively transport
across lamellar membranes
____________ – can empty
into nasal canals or mouth
http://animals.nationalgeographic.com/staticfiles/NGS/Shared/StaticFiles/animals/images/primary/marine-iguana.jpg
What other anatomy is significant?
Transitional
epithelium
lines the …
_________
&
_________
Contract =
What other anatomy is significant?
Transitional
epithelium
lines the
ureters &
urinary bladder
Stratified
&
Stretchy
Contract =
peristaltic
movements