Kidney numbers pt 2 Flashcards
Plasma oncotic pressure in afferent arteriole:
28 mmHg
Plasma oncotic pressure in beginning of glomerular capillaries:
28 mmHg
Plasma oncotic pressure at the end of glomerular capillaries:
36 mmHg
Hydrostatic pressure of the tubule:
18 mmHg
Protein osmotic pressure in the early part of the tubule:
0 mmHg
Net filtration pressure of kidney:
10 mmHg
Filtration rate of kidney:
125 mL/min
KF (filtration coefficient) in kidney:
12.5 mL/min/mmHg
How to solve for filtration coefficient?
Filtration rate / NFP
In kidney:
125 mL/min (filtration rate) divided by 10 mmHg (NFP) = 12.5 mL / min / mmHg
How did we get NFP of the kidney?
Take the pressure that promotes filtration - pressures that oppose filtration
60 mmHg (BP in glomerular capillaries) - 32 mmHg (osmotic pressure of glomerular capillaries) - 18 mmHg (Hydrostatic pressure of the tubule) = 10 mmHg
Filtration rate equation
Filtration rate = NFP x KF
Relaxation of the efferent arteriole = ____ upstream pressure, ___ filtration
reduced, less
Constriction of the efferent arteriole = ___ upstream pressure, ___ filtration
higher, more
BP at the end of the efferent arteriole
18 mmHg
Difference in bp between the glomerular capillaries and end of efferent arteriole
42 mmHg decrease
What % of stuff that is filtered is reabsorbed?
99%
What % of stuff that is filtered is excreted?
1-2%
Renal artery blood pressure
100 mmHg
Blood pressure of glomerular capillaries
60 mmHg (2x systemic caps)
Normal GFR
125 mL/min
Afferent arteriole plasma oncotic pressure
28 mmHg
Oncotic pressure in the beginning of the glomerular capillaries
28 mmHg
Oncotic pressure in the end of the glomerular capillaries
36 mmHg
Oncotic pressure in the middle of the glomerular capillaries
32 mmHg
Hydrostatic pressure in tubule or bowman’s capsule
18 mmHg
Oncotic pressure of tubule or bowman’s capsule
0 mmHg
NFP of glomerular capillaries
10 mmHg
Filtration coefficient of glomerular capillaries
12.5 ml/min/mmHg
BP at end of efferent arteriole
18 mmHg
Change in pressure from glomerular capillaries to end of efferent arteriole
42 mmHg
60-18 = 42
Change in pressure from renal artery to glomerular capillaries
40 mmHg
100-60=40
Peritubular capillaries plasma oncotic pressure
32 mmHg
Blood pressure of peritubular capillaries
13 mmHg
Renal interstitial oncotic pressure
15 mmHg
Renal interstitial physical fluid pressure or hydrostatic pressure
6 mmHg
Peritubular capillaries NFP
-10 mmHg
Peritubular capillaries net reabsorption pressure
+10 mmHg
Filtration rate equation
Filtration rate = NFP x Filtration coefficient
A little over ___% of the blood that moves through the kidney is filtered
10%
___ of the plasma that moves through the kidneys gets filtered
1/5
Filtration fraction of kidneys %?
20%
GFR (125) divided by renal plasma flow (660 mL/min)
Renal plasma flow in ml/min
660 ml/min
Renal blood flow in ml/min
1100 ml/min
Normal HCT
0.40
How do we get our plasma flow or volume for the kidneys?
Take 0.60 x 1100 (RBF) = 660
Kidneys will autoregulate between these blood pressures:
50-150 mmHg
Normal urine output
1 ml/min
How many nephrons are in each kidney at birth?
1 million
How many nephrons do we have at birth?
2 million (1 mil each kidney)
This percentage of nephrons are cortical nephrons
90-95%
This percentage of nephrons are deep medullary nephrons
5-10%
This percentage of peritubular capillaries are in the outer medulla
90-95%
This percentage of peritubular capillaries are in the inner medulla
5-10%
Where does the pudendal nerve come from
S2, S3, S4
What fraction of almost everything is reabsorbed at the proximal tubule?
2/3
The kidney can remove about ___% of PAH as blood passes through the kidney
90%
The brush border of the proximal tubule increases the surface area of its cells by ____
20 fold
Membrane potential of kidney cells
-70 mV
Proximal tubule tubular lumen charge
-3 mV
The amount of protein filtered each day in a normal healthy person
1.8 grams
How many grams of the filtered normal protein will be reabsorbed by the proximal tubule?
1.7 grams
How much protein shows up in the urine in a normal healthy adult per day?
100 mg or 0.1 grams
Pinocytosis only exists in this part of the kidney
proximal tubule
We reabsorb ___% of the water filtered in the proximal tubule and ___% in the thin descending limb
65%, 20% (so 85% reabsorbed by the time we are at the end of the loop of henle)
Tubular lumen membrane potential in thick loop of henle .WHy does it matter?
+8 mV
Pushes divalent cations through the paracellular route
Lizards can get their interstitial up to ___
3000 mOsm
What is the most concentrated our interstitium can be?
1200 mOsm
Plasma oncotic pressure in middle of glomerular capillaries:
32 mmHg
