Lecture 11/11: Renal Physiology Flashcards
Final
What is plasma oncotic pressure at the AA?
28 mmHg
What is plasma oncotic pressure at the middle of the GC?
32 mmHg
What is plasma oncotic pressure at the end of the GC?
36 mmHg
Why does oncotic pressure increase as you cross the GC?
Fluids are reabsorbed and not colloids therefore increasing the CONCENTRATION of colloids
What is hydrostatic pressure of bowman’s capsule?
Ptubule = 18 mmHg
_______ is used to manipulate auto regulation. ______ is used to fine tune GFR.
AA
EA
EA =
Efferent Artery
T/F: Autoregulation in the kidneys is a flat line
F
Slanted line
Describe autoregulation in the kidneys
Imperfect autoregulation that maintain a constant GFR and helps regulate BP long term
The line is slant and represents how the kidney is able to get rid of fluid when pressure is high and retain when low.
LL = 50
UL = 150
What happens to the things that stay in the nephron?
Get excreted in urine
What is the plasma oncotic pressure in bowman’s capsule?
0
_____% of filtrate in nephron gets reabsorbed
99
What is the normal rate of reaborption in the nephron?
124 ml/min
What is the name of the beginning of the nephron?
Bowman’s capsule
There are some proteins in the nephron. Describe their use. Do they contribute to oncotic pressure?
These proteins are strictly used for cell functioning in the nephron
They are tethered to the cell wall and are not floating around freely
They do not contribute to oncotic pressure
What is the NFP at the GC?
10 mmHg
Use formula and calculate
Need to memorize formula baby
Need to memorize normal values
Equation: Filtration Rate (GFR)
GFR = Kf x NFP
What is the Renal interstitium? What is its importance?
Matrix outside of nephron
Contains: proteins, ions, energy compounds, & filaments
** things reabsorbed into the PT cap/vasa recta have to go through here** <– very important for creating a gradient
PT cap =
Peritubular capillary
What type of blood is filtered through the kidneys?
Plasma
VR =
Vasa Recta
What is ∆P from upstream of the AA to the GC?
40 mmHg
What is ∆P from the GC to downstream of the EA?
42 mmHg
Which artery in the kidney is used to fine tune GFR?
EA
Which artery in the kidney has the highest vascular resistance?
EA
What is a hydrostatic pressure at the end of the EA?
18 mmHg
What is the second set of capillary beds in the kidney?
Peritubular capillaries/Vasa recta
What happens when you constrict/dilate the EA?
Constrict –> Increase GC pressure –> increase GFR
Dilate –> decrease GC pressure –> decrease GFR
Where does reabsorption occur?
All segments of the tubule
What is the hydrostatic pressure in the PT cap?
13 mmHg
What is the PT cap oncotic pressure?
Beginning: 36 mmHg
Middle: 32 mmHg
End: 28 mmHg
99% of fluids being reabsorbed here dilutes the colloids