module 2- renal Flashcards
1
Q
what is the job of the kidneys?
A
filter toxins out of the blood, maintains homeostasis even when several liquids are entering your body
2
Q
what are 3 things kidneys regulate?
A
electrolytes, water balance, pH
3
Q
7 functions of the kidney
A
1) regulate electrolytes
2) regulate water balance
3) maintain pH
4) excrete metabolic waste
5) excrete foreign compounds
6) secrete hormones
7) convert vitamin D into active form
4
Q
why do we need to excrete wastes?
A
so it does not accumulate & become toxic
5
Q
what 2 hormones are secreted by the kidneys
A
erythropoietin & renin
6
Q
kidneys are located
A
retroperitoneal on back (stuck to body wall, not free)
7
Q
ureter
A
collecting tube that takes urine to bladder
8
Q
what is the functional unit of the kidney
A
nephron
9
Q
3 kidney layers
A
1) renal hilus: inside
2) renal medulla: middle
3) renal cortex: outside
10
Q
horse vs dog vs cow kidney shape
A
horse: heart
cow: lobulated cortex
dog: bean shape
11
Q
2 parts of the nephron
A
vascular & tubular
12
Q
vascular vs tubular
A
v: blood containing portion
t: urine/filtrate containing portion
13
Q
what % of cardiac output goes straight to the kidneys?
A
20
14
Q
pathway of bloodflow to the kidneys
A
renal artery -> smaller arteries -> afferent arteriole -> glomerulus
15
Q
afferent arteriole
A
head of the nephron
16
Q
glomerulus
A
seam where 1st level filtration occurs
17
Q
pathway of filtration
A
efferent arteriole -> peritubular capillaries -> renal vein
18
Q
what capillary is like meshwork
A
pertitubular
19
Q
pathway of filtrate through the kidneys
A
bowmans capsule -> proximal tubule -> loop of henle -> distal tubule -> collecting duct
20
Q
T or F: loop of henle always dips into the medulla
A
T
21
Q
medulla is always on the ( ) & cortex is on ( )
A
bottom, top
22
Q
2 types of nephrons
A
cortical & juxtamedullary
23
Q
afferent vs efferent
A
a- blood comes in (arrives)
e- blood comes out (exits)
24
Q
macula densea cells
A
monitors fluid
too much= stops
too low= sends signal to increase
25
difference between cortical & juxtamedullary nephrons
c- located in the cortex, dips slightly into medulla
j- bowmans capulse in the cortex, loop of henle extends deeply into medulla
26
3 steps to urine formation
1) filtration
2) tubular reabsorption
3) tubular secretion
27
where does filtration occur
glomerulus
28
things that get reabsorbed
glucose, amino acids
29
pathway of filtration
afferent arteriole -> filtrate into blood -> secretion from blood to fluid
30
the sieve is part of ( ) and it contains 3 layers:
glomerular filtration
endothelium, basement membrane, podocytes
31
basement membrane
negatively charged membrane that repels negatively charged things & lets in positively charged
32
what are podocytes & how do they work
prevent plasma proteins from being filtrated
if contracted, they flatten & slits between them become smaller to block off entrance
33
what are 3 things that are filtered out vs not filtered
filtered- plasma, electrolytes & small peptides
not filtered- plasma proteins, red/white blood cells & platelets
34
T or F: urine is protein free
T
35
what does it mean if there is very little to a lot of protein in urine
little- exercise pushed a bit of albumin in
lots: kidney damage
36
do large or small molecules end up in the filtrate? why?
small bc large are too big to be filtered
37
capillary blood pressure favours
filtration
38
what controls how much blood enters the kidneys
the diameter of the arterioles
39
(more/less) pressure is easier for molecules to be filtered
more
40
how to increase bloodflow to the kidneys
dilate afferent arteriole & increase pressure
41
2 filtration forces
plasma-colliod pressure & bowmans capsule hydrostatic pressure
42
plasma colloid osmotic pressure
opposes filtration of plasma, higher concentration (less fluid) inside = water moves in
43
bowmans capsule hydrostatic pressure
opposes filtration of plasma, accumulation of water = pressure increases & causes backflow
44
net filtration pressure is
10mmHg (low)
45
kidney stone
pressure in capsule increases = decrease in filtration
46
burned victims
loss of plasma protein = less pressure = increase in filtration
47
GFR
glomerular filtration rate
48
GFR equation
GFR= net filtration pressure by Kf
49
kf
filtration coefficient, how much surface is available for filtering the glomerulus
50
increase in filtration pressure = ( ) of GFR
increase
51
how much filtrate is produced in your kidneys every day?
180L
52
how much pee is produced per day?
1.5-2L
53
T or F: cats/dogs filtration fraction is higher than humans but lower in goats
T
54
2 primary autoregulation mechanisms
myogenic & tubuloglomerular feedback
55
myogenic stretch mechanism
too much pressure = vasoconstriction
too little pressure = vasodilation
56
granular cells
sit on side of afferent artery & cause mascula cells to send signals to dilate/constrict arterioles
57
tubuloglomerular feedback/juxtoglomerular apparatus
monitors flow
58
kidney failure low GFR vs high GFR
low- kidneys do not excrete enough = accumulation of toxins in body
high- kidneys are losing water & solutes to urine
59
extrinsic (sympathetic) nervous control of GRF
1) increase sodium to get better water retention after blood loss
2) podocytes
3) baroreceptor reflex
60
baroreceptor reflex
long term correction of BP
decrease in BP = increase in SNS activity = vasoconstrict to conserve salt = causes increase in BP b/c you are not losing the water
61
T or F: SNS signals are local
F, they control entire body
62
what are 2 ways the body regulates GFR?
autoregulation-myogenic & juxo
sympathetic innervation
63
where are fluid/solutes reabsorbed
tubular portion of nephron
64
T or F: reabsorption is a highly selective process
T
65
how does fluid get reabsorbed?
solutes must pass through tubule cells b/c of tight cell junctions
66
sodium reabsorption
uses a pump to push Na out & decrease concentration of Na inside the cell = follows concentration gradient & balances things out
67
what is the main motor or reabsorption
sodium
68
T or F: sodium reabsorption is active
T
69
Na cotransporter
moves Na from lumen to cell and transports glucose, AA & phosphate to be reabsorbed
70
Na cotransporter vs Na/H antitransporter
c- lumen -> cell
a- cell -> lumen (1 H leaves per 1 Na entering)
71
secondary active transport only relies on ( ) as energy
sodium gradient
72
where is 65% of filtered out sodium reabsorbed? where is the rest?
proximal tubule, loop of henle & collecting duct
73
what 2 hormones control some of the Na reabsorption
aldosterone & ANP
74
RAAS signalling
renin-angiotension-aldosterone system
75
RAAS signalling goal
increase Na and water retention, and increase BP
76
Renin
enzyme that helps control blood pressure & maintains levels of Na & K
77
if BP is too low/high what hormones are released in RAAS signalling system?
low=renin
high=ANP
78
ANP
atrial natriuretic peptide
79
when is renin released?
low Na, low BP & SNS activation
80
4 steps of RAAS
1) renin or ANP is released
2) angiotension -> angiotension I
3) angiotension I -> angiotension II
4) angiotension stimulates release of aldosterone by adrenal glands
81
lungs contain a lot of
ACE: angiotensin converting enzyme
82
effects of angiotension II on kidneys
vasocontriction & sodium reabsorption
83
effects of angiotension of body
vasoconstriction, increased BP & ADH
84
ADH
antidiuretic hormone
85
when cells detect aldosterone, ( ) cells increase reabsorption of NA
principal
86
what does aldosterone excrete more of when controlling NA reabsorption
K+
87
ANP net effect
decrease blood pressure
88
where is ANP secreted
cardiac smooth muscle
89
ANP causes ( ) of afferent arteriole to lower BP
dilation
90
all waste products but ( ) are not reabsorbed
urea
91
maximal tubular transport
not all solutes can be reabsorbed from the tubule b/c there are not enough transporters
92
renal threshold
max concentration of solute in the plasma that can be completely reabsorbed from filtrate into the tubule
93
filtrate solute load equation
= plasma [solute] x GFR
94
diabetes mellitus
not enough transporters for glucose so glucose is lost in urine = sweet smell
95
normal Tm is
<1.75mmol
96
Tm
max amount of solute that can be reabsorbed
97
how do we secrete things that cannot be filtered at the glomerulus?
secrete into tubule from peritubular capillaries
98
what ion is always reabsorbed into the proximal tubule
K+
99
if K+ is lost what is caused
hypokalemia
100
acidosis
when Na is brought in & takes H out instead of K
101
hyperkalemia
too much K+ retention
102
what is secreted/what is by-product of tubular secretion
H- secreted
Na- by-product
103
renal clearance calculation
[solute in urine] x urine flow / [solute in plasma]
104
renal clearance measures
how much plasma volume is cleaned of a certain solute per unit of time
105
T or F: renal clearance measures amount of solute removed
F
106
how do dessert animals urine concentration work?
if no access to water = do not want to lose water = concentrate the urine
107
the osmotic gradient of the kidney is
ECF
108
medulla gets more ( ) as you get deeper into the medulla
hypertonic
109
hypertonic areas require (more/less) energy to maintain gradient
more
110
descending loop of henle
water is pulled from the tubule, and urine is more concentrated
111
ascending loop of henle
urine becomes hypotonic by pumping out salt but not water
112
3 benefits of counter current flow through loop of henle
hypertonic urine, hypotonic urine & osmotic gradient formation
allows control of water
113
where is there dilute urine found in the loop of henle
top curve
114
2 ways osmotic gradient is established
1) selective water permeability in tubule
2) selection ion transport in tubule
115
maintaince of gradient
water gets sucked out on the way down and salt gets sucked out on the way up
116
what ion follows Na when it gets pumped out
CI
117
where does control of water occur
distal & proximal tubule
118
T or F: distal & collecting duct are not naturally permeable to water
T
119
how much fluid still remains after the distal nephron
20%. = 36L
120
how do we absorb the remaining 20% of water?
use ADH to bind to V2 receptors on collecting duct principal cells & stimulates vesicles to unload aquaporins so the remaining water can be reabsorbed
121
how do diuretics work?
block V2 receptors = pee more = less volume in body = BP decreases
122
T or F: collecting duct is used for water reabsorption regulation
F
123
where is collecting duct found
proximal tubule of loop of henle
124
what occurs if no ADH is released vs it is released?
not released: distal & collecting tubes are impermeable to water and large volume of urine is super dilute b/c no water was reabsorbed, it all goes out in the urine
if released: distal & collecting tubes are permeable to water and small volume os urine is very concentrated b/c water was reabsorbed in the body
125
ADH causes ( ) urination b/c it ( ) water in the body
less, keeps
126
vasopressin/ADH ( ) BP
increases
127
where is ADH/vasopressin released
posterior pituitary gland
128
ADH release is controlled by what 3 ways
1) hypothalamic osmoreceptors
2) baroreceptors- sense drop in BP
3) angiotension II - sense drop in BP
129
how to fix a drop in BP?
release ADH to put more fluid in circulatory system
130
released of ADH is inhibited by what 2 things
1) low plasma osmolarity
2) alcohol/caffeine
131
how does alcohol/caffeine inhibit ADH?
blocks ADH = increase water excretion b/c no pull back of water occuring
132
how can ADH inhibition be overcome?
sleep and exercise- concentrate urine b/c do not pee during these states
133
hypotonic urine in relation to ADH
high volume of dilute urine b/c ADH has been blocked so you pee out the water your body has not absorbed
134
hypertonic urine in relation to ADH
max ADH response, small volume of concentrated urine produced when dehydrated b/c body is trying to conserve water
135
diabetes insipitus
large amount of dilute urine b/c body is constantly getting rid of water via urine
136
2 causes of diabetes insipitus
1) pituitary tumor- brain is not able to release ADH
2) kidneys cannot respond to ADH
137
symptoms of diabetes insipitus
pee more, dilute urine, tired
138
maximum urine osmolarity is based on ( ) in animals
aridity index- how dry the environment
139
wet vs dry environment effect on kidneys in animals
wet- lower urine concentration b/c lots of water available to drink
dry- small concentrated urine b/c little water available to drink = trying to conserve water inside so none is being lost via urine
140
what do longer loops of henle allow?
higher ability to concentrate urine b/c medulla is long & deep
141
concentration of medulla is proportionate to what?
depth of medulla
142
shallow cortex in animals = ( ) medulla
deeper medulla = longer loop of henle = concentrated urine
143
T or F: all mammal plasma osmolarity is the same
T
144
what does a higher medulla-cortex ratio mean?
deeper medulla compared to the cortex = more concentrated urine
145
why is urine yellow?
b/c of urobilin
146
what is urobilin
bilirubin metabolite
147
why would urine be red or brown?
red- RBC from after the kidneys
brown- hemoglobin from filtration issues
148
T or F: urine should be sterile (no microbes)
T
149
why does urine smell like asparagus
b/c of microalbuminuria protein
150
kidney stones
mineral crystals such as phosphate or oxalate crystals
151
struvite
magnesium ammonium phosphate
152
how to get rid of kidney stones
drink lots of water
153
uric acid stone vs gout
uric- due to lots of meat/protein
gout: uric acid crystals formed in joints
154
kidney stones may precipitate out of urine & cause pain if
mineral concentration in urine is too high
155
urine pH in carnivores vs herbivores?
C- acidic b/c amino acids in meat
H- alkaline
156
high pH = ( ) precipitation of minerals
higher
157
what may cause variation in urine composition
urine pH changes, species, animal condition
158
large kidney reserve pro & con
can donate kidney, but do not see clinical signs right away
159
how does anti-freeze cause renal disease
forms oxalate crystals in the kidney = causes acute kidney damage /failure
160
2 main concerns of kidney disease
1) decreased ability to concentrate urine
2) decreased waste removal from plasma b/c of decrease in GFR
161
azotemia
increase of ammonia & other nitrogenous compounds in blood = ulcers, vomiting, depression
162
3 other causes of kidney dysfunction
metabolic acidosis, hyperkalemia & anemia
163
metabolic acidosis
H accumulates in blood = lower pH = acidic blood = metabolic problems
164
hyperkalemia
dysfunctional hydrogen potassium exchanger causes excess H and K
165
hypoproteinemia
proteins are filtered out= low protein in blood = more protein in urine
166
anemia
decrease in erythropoietin = less RBC production
167
dialysis
artificial filtering of blood
168
hemodialysis
waste diffuses out of blood & clean blood gets pumped back into the patient
169
dialysis pathway
blood comes out from patient -> pumps through system -> blood goes into membrane -? dialysate fluid goes through gradient & discared -> clean blood is pumped back into patient
170
dialysate
isotonic solution with no waste products
171
peritoneal dialysis
use peritoneal as semi-permeable membrane & empty several liters of dialysis solution
172
T or F: peritoneal dialysis is less efficient than hemodialysis
T
173
UTI
bad bacteria travels up urethra & settles
174
UTI treatment
promote hydration, antibiotics & azo
175
how does cranberry juice interact with UTI
an active ingredient in this juice reduces adherence of bacteria to bladder wall, only helps with prevention, does not help once a UTI is formed
176
how does azo work for UTI
dye that turns urine orange & reduces pain while antibiotics have a chance to work
177
urinary tract blockage
plugs up urethra so urine cannot be excreted = urine accumulates = bladder bursts or backs up into kidney = hyperkalemia
178
autoimmune kidney disease
antibodies attack the glomeruls = no filtrate gets through = increase blood flow to functional nephrons = pressure increases
179
ethylene glycol
metabolized by AD & produces metabolite called oxalic acid = binds to Ca & produces crystals = plug up renal tubules
180
what de-activates AD for treatment of antifreeze?
4-MP and ethanol- outcompetes ethylene glycol for AD = flush it out of system
181
acid vs base
acid- donates H
base- accepts H
182
pH of venous vs arterial blood
A- 7.45
V- 7.35
183
acidosis vs alkalosis
acid- blood pH falls below 7.35
alka- blood pH is greater than 7.45
184
how to fix acidosis
increase respiration to eliminate excess H
185
what can pH changes do to proteins?
denature proteins = ions can no longer get through specific channels = disruption of nerve/muscle conduction
186
acidosis
drop in pH that depresses the CNS due to decrease in Ca = no AP
187
T or F: acidosis can lead to a coma
T
188
diabetic coma
due to ketoacidosis- brain switches to acidic ketone bodies
189
diarrhea from acidosis
secretions from pancreas & bile = loss of bicarbonate = accumulation of H = acidosis
190
alkalosis
increased blood pH, increased Ca, increased K
afferent- pins/needles
efferent- muscle twitches
191
why does acid-base status matter?
potassium homeostasis & H concentration
192
3 primary mechanisms of acid production
1) carbonic acid formation
2) nutrient breakdown- inorganic acids
3) metabolism- organic acids
193
henderson hasselblach equation
pH = pK + log [base]/[acid]
194
breakdown of acids vs bases
acids- meats = increase H
bases- fruits/vegetables = decrease H
195
fat metabolism
triglycerides converted to long chain FA
196
3 types of metabolism of organic acids
fat metabolism, fermentation, anaerobic
197
fermentation
short chain FA produced by rumen & absorbed in bloodstream
198
anaerobic metabolism causes
lactic acid production
199
3 controls of acid-base status
1) chemical buffers
2) respiratory compensation
3) metabolic (renal) compensation
200
what is the ratio for bicarbonate to H
20:1
201
T or F: bicarbonate cannot be used to drive the equation backwards
T
202
pK of bicarbonate
6.1
203
build up CO2 causes bicarb to H ratio to change to
21:2
204
protein buffer system
amino acids in proteins can accept or donate H
205
protein vs carbonate buffer locations
proteins = ICF buffer
carbonate = ECF buffer
206
hemoglobin buffer system
de-oxygenated hemoglobin has a greater affinity for H than oxygenated hemoglobin
allows H to be bound not free floating = maintains & buffers pH
207
phosphate buffer system
ICF & urinary buffer system
phosphate can bind H = more H umped out in urine = good
208
peripheral chemoreceptors detect H concentration in ( ) and central chemoreceptors detect H concentration in ( )
arterial blood, brain
209
what occurs when central chemoreceptors detect H in the brain?
signals respiratory centre to breathe more to bring in more CO2 & exhale H
210
when H decreases, receptors will cause a ( ) in ventilation so CO2 can ( )
decrease, build up
211
when does respiratory compensation kick in?
when chemical buffers are not sufficient
212
2 limitations of respiratory compensation
1) cannot fully correct it, just minimize
2) cannot compensate for respiratory induced acid-based problems
213
what is the 3rd line of defence for acid-base disturbances? what does it do?
kidneys- takes excess things in the blood & put into urine and reabsorb what we need from the urine & put it back in the blood
214
hydrogen potassium exchangers
move 1 H out & 1 K in
215
T or F: kidneys can regulate bicarb excretion
T
216
kidney reabsorption of bicarbonate
bicarb must form CO2 to diffuse bc it is negatively charged molecule & cannot diffuse across the cell
217
during alkalosis, bicarb is ( ) in the urine
stuck
218
what occurs if blood pH drops below 4.5
transporters cannot function
219
how to increase H secretion during acidosis
phosphate buffers = soak up excess H so more can be secreted
220
what is the 1st buffer in urine?
phosphate, and then ammonia
221
metabolic acidosis is fixed via
respiratory alkalosis
222
what is hypoventilation & how is it fixed?
PCO2 increases = H increase = acidosis
compensate with metabolic alkalosis
223
respiratory alkalosis is caused by
hyperventilation
224
what is hyperventilation
blowing off too much CO2 = PCO2 drops = H drops
225
normal [HCO3] in blood is (). what happens if it is over or under that?
24 mEq/L, metabolic acidosis if over and metabolic alkalosis if under
226
metabolic acidosis from gain of acid causes
1) diabetes- ketone bodies
2) animals in negative energy balance = uses ketone bodies
3) anaerobic metabolism = lactic acid production
4) grain overload = VFA increase = drops pH
5) uremia
227
uremia
cannot secrete H & reabsorb bicarb
228
metabolic acidosis causes from a loss of bicarb
diarrhea = fast = cannot absorb bicarb
229
metabolic alkalosis cause from a loss of H in body
severe vomiting = loss of H
230
metabolic alkalosis cause from a trap of H in GI tract
twisted abomasum=cuts off blood supply = H is not reabsorbed
231
metabolic alkalosis cause from a gain of bicarb
too many antacids
