Download Urinary

BI 203 Human Anatomy & Physiology II
How is urine produced?
Phases involved with urine
production:
1) _____________
movement of fluid/wastes
across filtration membrane
2) _____________
movement of substances (H2O etc.)
back into blood
4) ____________
regulating
concentration/vol.
3) _____________
active transport of solutes into filtrate
(inside nephron)
5) ____________
the act of urinating
BI 203 Human Anatomy & Physiology II
What is involved with producing filtrate?
Filtration Pressure…
Why is there a difference
in pressure?
= Glomerular capillary pressure
= Capsule pressure
= Colloidal osmotic pressure
BI 203 Human Anatomy & Physiology II
Take 5!!!
What effect does constriction of the
afferent arteriole have on the
filtration pressure? What effect
does a decrease in the concentration
of plasma proteins have on filtration
pressure?
Discuss with your
neighbor and predict
an answer.
BI 203 Human Anatomy & Physiology II
What components are in the blood that could
end up in the filtrate?
Plasma
180l
Filtrate
180l
Urine
1.8l
45000mg/l
1000
260
30
11
100
1000
260
30
11
0
0
18200
420
1960
142
5
103
28
142
5
103
28
128
60
134
14
BI 203 Human Anatomy & Physiology II
What is involved with producing filtrate?
Amount of cardiac output reaching kidneys =
Volume of blood/minute that renal fraction represents =
Volume of plasma/minute that renal blood flow rate
represents =
Amount of plasma and solutes that enters nephron =
Volume of filtrate produced/day =
BI 203 Human Anatomy & Physiology II
Take 2!!!
If the filtration fraction increases
from 19% to 22% what will the
daily volume of filtrate be?
Discuss with your
neighbor and predict
an answer.
BI 203 Human Anatomy & Physiology II
Why don’t we urinate 180 liters per day?
Steps of reabsorption:
1)
2) Water follows via _______
3) Water and solutes enter
_______________ (~ 300
mOsm/l)
4) Low pressure in
_______________________
5) Water and solutes ______
___________
BI 203 Human Anatomy & Physiology II
What form of epithelium would you
expect to facilitate reabsorption?
*
*
Why abundant
mitochondria?
BI 203 Human Anatomy & Physiology II
How many liters still need reabsorbed?
Reabsorption in _________
_________________:
> concentration of
__________________ in
medulla (_________)
More ______________ and
some solutes move in
(_____________________)
BI 203 Human Anatomy & Physiology II
Water has been reabsorbed but what about the
salts?
Reabsorption in
ascending loop of
Henle:
Tubule __________
_________
________________
occurs (sparing
salts)
Filtrate becomes
dilute (__________)
BI 203 Human Anatomy & Physiology II
How much has been reabsorbed from the
filtrate thus far?
80% of 180 l =
144 liters
How much is
left?
How many
liters of urine
would that be?
?
?
?
BI 203 Human Anatomy & Physiology II
How is the remaining filtrate volume reduced?
Distal tubule mostly impermeable to H2O… BUT
under hormonal control. ______________________
________________________
BI 203 Human Anatomy & Physiology II
Take 2!!!
If a blood clot in the brain caused
damage to the hypothalamus what
might the effect be on urine
production and why?
Discuss with your
neighbor and predict
an answer.
BI 203 Human Anatomy & Physiology II
What is the role of secretion in urine production?
Moving wastes
into nephron both
passive and active
______________
Active /
countertransport
(_____________)
BI 203 Human Anatomy & Physiology II
Why is the secretion of H+ important?
We produce about 60ml of acids
in the form of _________,
____________ and _______
acids as a result of digestion.
H+ combine with HCO3- to
form _________, which
disassociates to form H2O and
CO2.
Some of the CO2 is exhaled
So where does the HCO3- come from?
BI 203 Human Anatomy & Physiology II
Why is the secretion of H+ important?
The kidneys help generate a sink for
the H+, which helps drive the reaction
of…
The ______ can then combine with
metabolic ____ and the cycle is
complete