renal Flashcards
(168 cards)
1
Q
What is the role of the renal system
A
Excretion
Water/electrolyte balance
pH regulation
Control of circulating volume
2
Q
What vertebra level are the kidney located at
A
L1-L4 when standing
3
Q
What is the inner portion of the kidney
A
Medulla
4
Q
What is the outer part of the cortex
A
Medulla
5
Q
What cord level innervates the kidneys
A
T12
6
Q
What does sympathetic stimulation of the kidneys do
A
Constriction of arterioles
decrease flow of fluids = decreased output
Increase sodium reabsorption
Increase renin release
7
Q
how many capillary beds does the kidneys have
A
2 capillary beds
8
Q
What are the two capillary beds in the kidneys
A
Glomerular capillaries
Peritubular capillaries
9
Q
What is the order of kidney blood flow (in)
A
Afferent arterioles
Glomerular capillaries
Efferent arteriole
peritubular capillaries
10
Q
What causes the rapid fluid filtration at the glomerular capillaries
A
High hydrostatic pressure
11
Q
What allows for rapid fluid reabsorption at the peritubular capillaries
A
Low hydrostatic pressure
12
Q
What are the two different nephron structures
A
Cortical nephron
Juxtamedullary nephron
13
Q
What is the difference between cortical and juxtamedullary nephron
A
Juxtamedullary nephron is longer and penetrates deeper into the medulla
14
Q
Can the kidney regenerate new nephrons
A
No
15
Q
how many functional nephrons do you lose each year
A
10% every 10 years
16
Q
does filtration effectiveness change as we age/lose nephrons
A
no
17
Q
what encases glomerular capillaries
A
Bowman’s capsule
18
Q
What type of nephron is most common
A
Cortical
19
Q
what nephron is surrounded by Vasa recta
A
Juxtaglomerular
20
Q
what precent of nephrons are juxtaglomerular
A
20-30%
21
Q
how much does the pressure in the urinary bladder increase by when detrusor muscle contracts
A
40-60 mmHg
22
Q
What part of the urinary bladder do the ureters enter
A
The upper trigone
23
Q
Where is the trigone of the bladder located
A
The posterior wall
24
Q
What is special about the surface of the trigone
A
It is smooth muscle with no rugae
25
What prevents backflow of urine into the ureters
THe tone of the detrusor muscle
26
Is the external urinary sphincter voluntary or involuntary
Voluntary
27
What nerve innervates the external urinary sphincter
The pudendal nerve
28
what cord levels provide parasympathetics to the urinary bladder
S2
S3
Via sacral plexus
29
What is the order of urine flow
```
Nephron
Collecting ducts
Renal calyces
Ureters
Bladder
```
30
What is the Ureterorenal reflex
When there is pain in ureters renal arterioles constrict and decrease flow of fluid to kidneys
31
The ureterorenal reflex sends sympathetic or parasympathetic signals to the kidneys
Sympathetic
32
What is micturation
The process of emptying the bladder
33
What does it mean by the micturation reflex is self-regerative
Contracture of the detrusor muscle causes further activation of the stretch receptors
The longer you hold it in you will feel more pain and the sensation to pee will come back faster
34
What happens to micturation reflex as the bladder fills
Increase frequency of reflex
| Increase intensity of reflex
35
Can the micturation refelx affect the external sphincter
Yes, and eventually the relaxation of it will be involuntary if held too long
36
What starts the micturation reflex
Sensory stretch receptors in the bladder wall
37
What is the average amount of fluid excreted via kidneys each day
1400ml/day
38
What are the parts of extracellular fluid
Interstitial fluid
Blood plasma
Transcellular fluid
39
what ions are high and low in intracellular fluid
```
Low= sodium, calcium, chloride
High= potassium, phosphate
```
40
what ions are high and low in extracellular fluid
```
Low= potassium, phosphate, proteins
high= sodium, chloride, bicarbonate
```
41
what is the definition of Osmolarity
Osmoles per liter of water
42
what is it called when a solution has a lower concentration of solutes than the cell
Hypotonic
43
What is it called when a solution has a higher concentration of solutes than the cell
Hypertonic
44
What is the most variable source of water loss from the human body
Urine
45
what type of blood vessels deliver blood to the renal corpuscle
Afferent arteriole
46
what should not filter out of the blood under normal circumstances
Red blood cells and plasma proteins
47
What is special about the membrane of glomerular capillaries
They have 3 layers instead of two
48
What prevents the passage of plasma proteins in the glomerular capillaries
The endothelium is negatively charged
49
What part of the basement membrane has a strong negative charge that prevents proteins from passing though
The proteoglycans
50
Is the epithelium layers of the renal corpuscles negativley charged
yes
51
What allows for filtration in the bowmans capsule
Blood colloid osmotic pressure caused by proteins
52
What is renal plasma flow
Volume of blood plasma delivered to the kidneys
53
What is Filtration Fraction
Proportion of the fluid reaching the kidneys which passes into the renal tubules
54
What is the average filtration fraction
20%
55
What is the average renal plasma flow
550 ml/min
56
How can renal plasma flow be altered
Increase overall cardiac output
| Dilate afferent arterioles
57
How can Filtration Fraction be altered
Contract efferent arterioles, increasing glomerular pressure
58
What causes/favors filtration
Glomerular hydrostatic pressure 60mmHg
| Bowman's capsule colloid osmotic pressure 0mmHg
59
What causes/inhibits filtration
Bowmans capsule 18mmHG
| Glomerular cap colloid pressure 32mmHg
60
What is the equation to calculate Filtration fraction
FF=GFR/RBF
61
What happens to glomerular filtration when membrane permeability decreases
it decreases
62
What happens to GFR when bowmans capsule pressure increases
Decrease GFR
63
What happens to GFR when Glomerular colloid pressure increases
Decreases GFR
64
What happens to GFR when Glomeular hydrostatic pressure increases
Increase GFR
65
What happens to GFR when arteriol pressure increases
GFR increases
66
Dilation of afferent arterioles will do what to GFR
Increase GRF
67
What part of the kidney receives most of the renal blood flow
The cortex
68
What supplies the Renal medulla with nutrients
The vasa recta
69
What does Angiotensin II do to the kidneys
Maintain GFR when BP drops (prevents drop in GFR)
70
What changes to filtration when Angiotensin II is released
Increase reabsorption of sodium and water
71
What happens when renal cells sense a decrease in sodium concentration
Decrease blood flow in afferent arterioles (increase GFR)
Renin released (increase GFR)
72
Filtration and reabsorption are high/low compared to excretion rate
High
73
What is excretion rate equal to for electrolytes
Filtration rate - reabsoption rate
74
What does it mean when excretion rate = 0
NO exretion in the urine
75
What is excretion rate equal to for organic acids and bases, foreign substances, and drugs
Filtration rate + secretion rate
76
What happens if the basement membrane loses its electrical charge
Albumin is filtered and will be in urine
77
What is vital in determining excretion rate
Tubular reabsorption
78
What is more selective; Glomerular filtration or Tubular reabsorption
Tubular reabsorption is more selective
79
What are the steps of tubular reabsorption
Transported across the epithelial membrane
into interstitial fluid
through peritubular membrane
into blood
80
What can travel through tubular epithelium
Water and solutes
81
Where is sodium transported
Proximal tubule
82
What type of transport is required to transport sodium from the proximal tubule cells into the interstital fluid
Active transport via sodium potassium ATPase pump
83
What transports glucose into cell against concentration gradient
SGLT2
| SGLT1
84
What process allows for the movement of glucose
Release of energy from ATP (secondary active transport)
85
What is counter transport in the kidney
Secretion of a substance into the tubule by secondary active transport
86
What substances do not demonstrate a transport maxium
Substances that are passivly absorbed
87
Which is greater:
Maxiumum transport capacity of basolateral sodium ATPase pump
Or
THe actual rate of sodium reabsorption
The maximum transport capacity of basolateral sodium ATPase pump
88
what is the limit to the rate at which a solute can be transported during active reabsorption or secretion
Transport maximum
89
How are proteins and amino acids reabsorbed in the kidneys
Pinocytosis
90
What percent of filtered water and sodium is reabsorbed
65%
91
What can transport sodium across a cell
Co-transporters
Counter-transport mechanism
Sodium-potassium ATPase pump
92
What allows the proximal tubule to keep a constant osmolarity
It is highly permeable to water
93
What is secreted in the proximal tubules
Organic acids + bases
| Drugs + toxins
94
What is the primary function of the thin desceding segment of the loop of henle
Allow for simple diffusion
95
What happens in the thick ascending segment of the loop of henle
Active reabsorption of sodium, chloride and potassium
96
Can water pass in the thick ascending loop of henle
No
97
What is the first portion of the distal tubule called
Macula densa
98
What % of sodium is absorbed in the proximal distal tubule
5%
99
What is the job of Principal cells
Sodium reabsorption
| Postassium secretion
100
What is the job of intercalated cells
Hydrogen secretion
| Bicarbonate+potassium reabsorption
101
What determines water permability in the distal tubules
ADH (Vasopressin)
high=high permeability
low=low permeability
102
What is water reabsorbtion dependent on in the medullary collecting ducts
ADH levels
103
What portion of the loop of henle do we significant sodium transport
Thick ascending
104
How has osmolarity changed when the filtrate reaches the end of the proximal tubule
Stayed the same
*high permeability to water keeps it the same*
105
What percent of water and most solutes are reabsorbed
99%
106
what determines reabsorption across peritubular capillaries
Hydrostatic and colloid osmotic forces
107
What forces favors reabsorption
Plasma colloid osmotic pressure = 32mmhg
| Hydrostatic pressure in interstitum = 6mmHg
108
What forces oppose reabsorption
Peritubular hydrostatic pressure = 13mmHg
| Osmotic pressure of the renal interstitum = 15mmHg
109
What is the glomerular capillary net filtration forces
10mmHg
110
What is the peritubular capillary net re-absorptive forces
10mmHg
111
What determines filtration coefficient
Surface area of capillary
| Permeability of capillary
112
What happens if we raise peritubular capillary pressure
Decrease reabsorption rate
113
What happens if peritubular capillary pressure decreases
Increase reabsorption
114
What happens if we increase resistance at the effernt arteriole
Incresae glomerular pressure
| Decrease peritubular pressure
115
What is Natriuresis
Na excreted in urine
116
What is Diuresis
Water excretion to regulate BP
117
What secretes aldosterone
Zona glomerulosa cells of adrenal cortex
118
What does aldosterone do to kidneys
Regulates sodium reabsorption and potassium secretion
119
When is aldosterone relseased
Increased extracellular potassium
| increased angiotensin II levels
120
What does ADH do
Increase water permability in the
Distal tubule
Collecting tubule
Collecting duct
121
What does ANP do
Inhibit renin
| inhibit reabsorption of sodium potassium
122
When is ANP released
In congestive heart failure
123
What does angiotensin II do
Increase sodium and water reabsorption when BP is low
124
What does angiotensis II do to the efferent arterioles
Constricts them
125
What pH would make someone be in a state of acidosis
Below 7.4
126
What pH would make someone be in a state of alkalosis
above 7.4
127
What is the most powerful regulator of pH in the body
Kidneys
128
How long does it take for the kidneys to react to a change in pH
hours to days
129
What part of the tubule does Hydrogen secretion no occur
Thin ascending and thin descending limb of the loop of henle
130
Where does HCO3- reabsorption occur
```
Proximal tubules (80-90%)
Thick ascending (10%)
```
131
Where is H+ secreted
Proximal tubule
Thick ascending limb
Early distal tubule
132
Where does Primary active transport of HCO3- occur
Late distal tubule and collecting tubule
133
What causes respiratory acidosis
increase Pco2
134
What causes metabolic acidosis
Fall in HCO3-
135
How does urine become acidic
Excess H+ in renal tubules causing complete reabsorption of HCO3-
136
What amino acids get used by the kidneys for Gluconeogenesis
Lactate
Glutamine
Glycerol
137
What is the osmolarity of the filtrate in the proximal tubule
300mOsm/L
138
When does Osmolarity start to increase
The descending segment of the loop of henle
139
What happens to osmolarity in the ascending portion of the loop of henle
It decreases
140
What happens to the osmolarity at the collecting tubules in the absence of ADH
Dilute urine
| Low osmolarity
141
What happens to the osmolarity at the collecting tubules in the presence of ADH
Concentrated urine
| high osmolarity
142
what are the basic requirments for forming a concentrated urine
High levels ADH
| High osmolarity in medulla tissue
143
What creates hyperosmotic renal medullary interstitial fluid
Justamedullary nephrons
| Vasa recta
144
What is the concurrent multiplier
Repetive reabsorption of sodium chloride in thick ascending loop and continued inflow of new sodium from the proximal tubule
145
what is the contribution of Urea to osmolarity of the renal interstitium
40-50%
146
What might be recycled many times between the medulla tissue and the filtrate in the renal tubule
Urea
147
What can be used to determine concentration of urine
Colour
| Urine specific gravity
148
What happens if sodium content increases 2mEq/L above normal
Causes a desire to ingest fluid (threshold for drinking)
149
What can be done to control extracellular fluid if the kidneys can't
Change BP
Change circulating hormones
Change sympathetic NS
150
What is it called when there is a rise in sodium that ocures with elevated BP
pressure natriuresis
151
What is it called when increased BP raises urinary volume
Pressure diuresis
152
What mechanism as long as it is working handles increases in fluid and salt intake
Pressure diuresis mechanism
153
a small Change in blood volume do what to cardiac output
Marked increase in cardiac output
154
A small change in cardiac output would do what to BP
Increase BP
155
a small change in BP does what to urine output
Increase urine output
156
What happens to urine output if there is a small change in blood volume
Increase urine output
157
What happens to a persons BP if they are salt sensitive and take in a small amount of salt
Marked increase in BP
158
What is the bodies more powerful controllers of sodium excretion
Angiotensis II
159
What drugs increase ADH secretion
Morphine
Nicotine
Cyclophosphamide
160
What drugs inhibit ADH
Alcohol
Clonidine
Haloperidol
161
What happens to pH when there is an increase of Extracellular postassium
Acidosis
162
What happens to pH when there is a decrease in potassium levels
Alkalosis
163
WHere is most of the potassium reabsorbed
Proximal tubule
164
What cells secrete potassium for excretion
Principal cells
165
What controls potassium secretions by the principal cells
Sodium-potassium ATPase pump
Electrochemical gradiant
Luminal membrane permebility
166
What cells reabsorb potassoium
Intercallated cells
167
Calcium in the blood is attached to what
Proteins
168
Where is most of the calcium in the kidneys reabsorbed
Proximal tubules
