Renal Physiology Intro And Clearance Flashcards
1
Q
What is the in the middle of the kidney
A
Hilium
2
Q
Where is the site of the renal artery, renal vein, and ureter entrance/exit
A
Hilum of kidney
3
Q
What are the two parts of the kidneys
A
Cortex and medulla
4
Q
What is the functional unit of the kidney
A
Nephron
5
Q
What filters blood to make urine
A
Nephron
6
Q
Where does renal artery enter the kidney
A
Hilum
7
Q
What does the renal artery do
A
Provides blood flow to the nephrons
8
Q
How does urine collect
A
In papilla, drains into renal pelvis, and ureter
9
Q
How does blood drain out of the kidney
A
Through the capillaries back in renal vein
10
Q
General renal functions
A
- regulation of water balance
- maintain normal electrolyte concentrations and content
- conserve nutrients
- excrete wastes
- regulate CO and BP
- control hematopoiesis
11
Q
Water intake + metabolic water=
A
Renal excretion + GI excretion + evaporation
12
Q
If the regulation of water balance is negative
A
Lose total body water
13
Q
If the regulation of water balance is positive
A
Gain total body water
14
Q
What is the minimum amount of urine needed per day
A
1/2L
15
Q
Where are the places we lose water
A
GI, evaporation. Evaporation is the number 1 way
16
Q
How does the kidney maintain normal electrolyte cxn and content
A
Regulate electrolyte and water excretion to control electrolyte amount AND concentration in plasma
17
Q
What are the two different kinds of nephrons
A
Cortical (superficial)
Juxtamedullary nephron
18
Q
Cortical (superficial) nephron
A
Superficial, short loop of henle, mostly stays out of medulla
19
Q
Juxtamedullary nephron
A
Long loop of henle, can go down to the papilla.
20
Q
What type of nephron has the longest loop of henle
A
Juxtamedullary nephron
21
Q
What kind of nephron has the vasa recta
A
Juxtamedullary nephron
22
Q
What does the vasa rectus do
A
Slow moving blood supply to make concentrated urine
23
Q
Where is the 1st step of urine production in the kidney
A
Glomerular capillaries
24
Q
What do the glomerular capillaries do
A
Filters plasma into nephron, makes tubular fluid
25
What are the glomerular caps fed by
Afferent arterioles
26
What is the glomerular caps drained by
Efferent arterioles
27
How does the glomerular caps control blood flow
Can control diamter of each arteriole
28
What is the pressure in the glomerular caps
Very high due to the two arterioles on either side
29
Normal caps, fed by efferent arterioles
Peritubular caps
30
What wraps around the nephron
Peritubular caps
31
What are the peritubular caps required for
Reabsorption and secretion
32
Filter plasma to form tubular fluid (urine). Filter load is the amount filtered in caps. Amount filtered is not always the same as excretion
Filtration
33
Is the amount filtered the same as the amount excreted
Not always
34
What is removed from the body via urine
Excretion
35
Remainder of tubular fluid and solutes at the end of the nephron
Excretion
36
What is the excretion rate of X?
Urine flow * [X]
37
Moves solutes/ water from tubular fluid back to blood
Reabsorption
Kidney taking it from peritubular fluid and putting it back into the blood
38
Moves solutes from blood into tubular fluid
Secretion
Kidney decides it shouldn't be in the blood. Filters things out
39
What happens between filtration and excretion
Reabsorption and secretion
40
What is the hollow tube that create the tubular fluid
Nephron
41
What order does the nephron go in
Glomerulus--PCT--loop of henle--DCT--collecting duct
42
Capillary bed that filters blood to produce urine
Glomerulus
43
What is the first step in urine production
Glomerulus
44
Cup shaped entrance to nephron surrounds glomerulus that has arterioles on both sides
Bowmans capsule
45
What is the filtration caused by in the kidneys
The same as in Theo ther parts of the body
46
What is the first step in ruin production
Filtration
47
What is the second step in urine production
PCT
48
What is the main site of reabsorption
PCT
49
67% of ions (Na, K, Ca) and water, all glucose and amino acid reabsorption
PCT
50
What does the PCT have to do with secretion
Secretion of some metabolites and drugs
51
What are most transport mechanisms dependent on
Na/K ATPase
52
Where do carbonic anhydrase inhibitors have diuretic effects
PCT
53
Where does reabsorption and dilution of urine occur
Loop of henle
54
What is the 3rd step in urine production
Reabsorption and dilution of urine at the loop of henle
55
Where is the water reabsorption and no solute movement in the loop of henle
Descending limb
56
Where in the loop of henle do solutes get reabsorbed and no water movement
Ascending limb
57
What sets up gradient used to alter urine concentration
Loop of henle
58
Where is the osmolarity the highest?
At the bottom of the loop of henle
59
Part of the juxtaglomerular apparatus that sense tubular flow and renal blood flow
Macula densa
60
Loop diuretics
Furosemide (lasix) take action at the loop of henle
61
What is the 4th step of urine production
Fine control and pH balance at the distal convoluted tubule
62
Where does fine control and pH balance in urine production happen
Distal convoluted tubule
63
Where do thiazide antidiuretics work
Distal convoluted tubule
64
What is the 5th step in urine production
Collecting ducts
65
Regulation of water reabsorption and final control of urine osmolality. Pulls a lot of water out to concentrate the urine
Collecting ducts
66
How many collecting ducts per nephron
1 duct drains may nephrons
67
Site of anti diuretic hormone function
Collecting ducts
68
What makes the collecting ducts permeable to water only
Anti-diuretic hormone
69
Where do potassium sparing diuretics take place
Collecting ducts
70
Glucose is removed from the tubular fluid by active transport and returned to the blood, this is an example of what kind of renal process
Reabsorption
71
In periods of hyperglycemia like DM, some filtered glucose is lost to the urine. This is an example of what kind of renal process
Excretion
72
The most water reabsorption in which segment of the nephron
Proximal convoluted tubule
73
The most Na is reabsorbed in which segment of the nephron
PCT
74
The most unicorns is reabsorbed in whih segment of the nephron
PCT
75
Filtration + secretion - reabsorption=
Excretion
76
Urine flow * [urine]=
Excretion
77
What begins everything into the kidneys
Renal artery
78
What dies kidney only filter
Blood plasma
79
What is Renal function
How much stuff was removed from the blood
80
BV=
PV/(1-hematocrit)
Hmct is volume of blood cells
81
Plasma volume is about _____ of total blood volume
40%ish
82
Input of solute
Amount delivered to kidney
83
Input of solute
RPF*(Xa)
RPF=renal plasma flow
Xa= cxn in blood plasma
84
Renal output
Solute leaving the kidney in urine AND renal vein
85
Renal output equation
(RPF*(Xv))+(Xu*V)
Xv= cxn in renal vein
Xu= cxn in urine
V=urine volume
86
Relationship of output and input
Should equal
| RPF*(Xa)=(RPF*[Xv])+(Xu*V)
87
What allows for determination of clearance of a solute
The fact that input=output
88
As plasma moves through kidney
Solutes are removed from it
89
Volume of plasma that has had a solute removed from it in one minute
Clearance
90
What does clearance compare
Urine and plasma levels to determine amount removed
91
How is clearance expressed
Volume/time (mls/min)
92
Equation for clearance
CN=(Xu*V/Xa)
93
What is the basis for determine renal function
Clearance
94
What can clearance determine
Plasma filtered, amount of blood delivered to kidney
95
Clearance of inulin
Glomerular filtration rate
| -amount of plasma filtered by kidneys
96
Clearance of PAH
Renal plasma flow
- 100% filtered and 100% secreted
- tells you how much plasma moved through kidney
97
Amount of plasma that is filtered by the kidney
Filtration fraction
98
Equation for filtration fraction
FF=GFR/RPF
| Usually about 20%
99
Tells us how much water we are excreting
Free water clearance
100
When is free water clearance helpful
When we want to think about the osmolality of the ECF and if the kidneys are working correctly in trying to fix a problem
101
Is plasma osmolarity were too high, what would we want
Excrete the minimum amount of water. Retain water to dilute ECF
102
If plasma osmolarity were too low, what would we want
Get rid of water. Urine is diluted
103
How do we calculate the renal clearance of total osmoles
Cosm=(Uosm*V)/Posm
104
What does renal clearance of total osmoles tell us
Volume from which all solutes have been removed
105
What would happen if osmolar clearance is 1ml/min but our urine flow was 3ml/min
Body needs 1ml/min of urine to remove all of the dissolved stuff, but produced 3mls/min. The extra 2mls is free water, water that has no dissolved substances
106
Total clearance-Osm clearance=
Free water clearance
3mls/min-1ml/min=2mls/min
107
If free water clearance is positive (more water cleared than solutes)
- body is over hydrated, ECF osmolarity is low
- have more water than necessary so lots of dilute urine is appropriate
- lose free water to increase ECF osmolarity
108
If the free water clearance is negative (more solute cleared than water)
- body is dehydrated, ECF osmolarity is high
| - have less water (more solute), so small amounts of cxn urine is appropriate
109
Can you preserve water in times of no water?
You can't preserve enough water to correct a hyperosmotic ECF, only slow its progression
110
If Uosm>>>>Posm
You should have a negative Cwater
-appropriate when Posm is high
-need to keep water in body
Usually a low urine flow rate
111
If Uosm<<<<
You should have a positive C water
- appropriate when Posm is low
- need to lose water from body
- usually a high urine flow rate
112
Posm=335mOsm/L, Usom=156mOsm/L, Uflow=4mls/min
Is this an appropriate free water clearance
No
Decreases Uosm not good for preserving water
Increase Uosm needs to be higher, flow rate as low as possible
113
Normal plasma osmolarity (Posm)
285-295
114
Normal urine flow rate
2mls/min
