Week 4 Flashcards
(187 cards)
1
Q
Differences between Juxtramedullar and Cortial Nephron
% of each?
Loop of Henle?
Location of glomerulus?
A
85% / 15%
Short / Extends a lot into medulla
Cortex / Border of cortex and medulla
2
Q
Which nephron generates osmotic gradient?
A
Juxtamedullar Nephron
3
Q
What structures are proximal to glomerulus?
A
Afferent arteriole, efferent arteriole, and distal convoluted tubule
4
Q
What is the general pattern of the resistance to the flow of fluid in nephron?
What regulates the paracellular water flow?
A
The resistance increases
The types of protein in tight junctions
5
Q
What is the general patter of water permability?
What protein affects permiability of water in collecting duct?
A
Water not permeable in ascending limb and distal convoluted tubule
Antidiuretic hormone (ADH) aka Vasopressin (AVP)
6
Q
What are the “water holes” called?
Which aquaporin is regulated by ADH?
A
Aquaporins
AQP2 (Gs-PKA pathway)
7
Q
What blood vessels supply PCT and DCT?
In which nephrone does efferent artery has two routes?
A
Peritubular capillaries
Juxtamedullary (peritubular and vasa recta)
8
Q
Diagram of the renal Circulation
A
9
Q
Where is Juxta glomerular apparatus?
What cells sense flow?
Where are they?
What cells are associated with afferent and efferent artery?
What is their function?
A
Distal convoluted tubule
Macula densa
Distal convoluted tubule
Juxtaglomellular cells
Secrete renin
10
Q
What does the TGF stand for?
What is it?
A
Tubuloglomerular feedback
A mechanism that serves to maintain a relatively **constant GFR ** by sensing NaCl levels in the distal nephron and releasing substances that feed back onto the glomerulus to modify arteriolar resistance.
11
Q
What is the mechanism that maintains a constant GFR?
What is the mechanism when the flood to glomerulus is too slow?
A
Tubuloglomerular feedback
12
Q
What is the mechanism when the flow to glomerulus is too high?
A
Mediated by adenosine binding from macula densa to cells surrounding afferent arteriole
Less renin release
Constriction of afferent arteriole
13
Q
RBF
A
Renal blow flow
14
Q
How changes in the resistance of afferent and efferent arteriole affect the
renal blood flow
pressure in glomerulus
glomerular filtration rate
A
15
Q
What is the filtration fraction?
Equation?
What happens if the efferent arteriole contracts?
A
The percentage of renal plasam that gets filtered
FF = GFR / RPF
FF goes up
16
Q
Purpose of autoregulation of blood flow in kidneys
Two mechanisms for autoregulation
A
To mantain a constant pressure in glomerulus
Myogenic and tubuloglomerular feedback (TGF)
17
Q
What are other mechanisms for regulation of renal blood flow except autoregulation?
A
Nerves
Hormones (RAAS)
18
Q
What three mechanisms cause renin release?
A
Less strech in afferent arteriole
Decrease in NaCl in DCT
Sympathetic Activity
19
Q
What are the effects of Angiotensin II
A
Contract arteriorle (efferent arteriol preference)
Brain enhances thirst and ADH release (water absorption)
Stimulates sympathetic nerves
Adrenal gland release NE, E, and aldosterone (Na+ absorption)
20
Q
Acute Renal Failure
What is it?
What is importance of prostaglandins and acute renal failure (in cases of percieved or real blood loss)?
A
Retention of waste products (urea and nitrogenous waste) and disregulation of volume and electrolytes
Low volume leads to sympathetic activation that leads to renin (contraction) and prostaglandins (dialation). Sone NASIDs can cause decrease in prostaglandins and lead to further constriction and lowering the filtration rate.
21
Q
Which blood vessels in kideny are acted preferentially by renin?
A
Efferent
22
Q
How is the consumption of oxygen releated to flow?
A
GFR = Na+ reabsorption = Renal oxygen consumption
23
Q
What might be a cause (potentially) of taking ACE inhibitor (in case of stenosis where cells do not feel pressure)?
A
Hypertension
Aggrevated by ACE inhibitor can lead to Acture Renal Failure
24
Q
Ouabain function
A
Increase Na/K ATPase activity
25
Three types of peritoneum
Visceral
Pericardial
Mesentary (suspending)
26
Is Gut in peritoneum?
No
27
Retroperitoneal structures
examples?
Intraperitoneal structures?
Kidney, ureter, aorta, inferior vena cava, posterior abdominal wall, and bladder
Stomach, liver
28
Name this muscle
Origin?
Insertion?
External oblique
Ribs 5-12
Rectus sheet (aponeurosis)
29
Name this muscle
Origin?
Insertion?
Latissimus dorsi
thoraco-lubar aponeurosis
Floor of intertubercular groove of the humerus
30
Name this muscle
Origin?
Insertion?
Internal oblique
Inguinal ligament, Iliac crest
Linea alba
31
Name this muscle
Insertion?
Origin?
Transversus abdominis
linea alba
thoracolumbar fascia
32
Name this muscle
Origin?
Insertion
Quadratus Lumborum
**iliac crest** and iliolumbar ligament
Last rib and **transverse processes** of lumbar vertebrae
33
Which rib is kidney laying on?
Which kidney is lower? Why?
Do kidneys move during respiration?
12th
Right 2-3cm (liver)
Yes 2.5cm
34
By what fat is kideny surrounded by?
What separates these two fat layers?
What separates kideny and adrenal glands?
Peri and para renal fat
Renal facia
Renal facia
35
Where do the kideny start to develop?
Because of that where the autonomic innverations come from?
In pelvis
Pelvic splanchnics / Vagus
36
Polar arteries
Arteries that formed to support kidney
37
Name the main blood supply to kideny
Which one is longer artery/vein and left/right
Problem with left renal artery?
What do these arteries split into?
Where else the left receives blood?
Where else the left can supply blood?
Renal artery / vein
Longer: Right artery, left vein
Superior mesenteric artery syndrome (affect left renal artery due to pressure)
Anterior and posterior segmental branches
Left gonadal vein
Connection to azygous system
38
List structures in kideny
Capsule
Cortex
Medulla (renal pyramid / papilla)
Minor calyx
Major calyx
Pelvis
Ureter
39
Sympathetic innervations to kideny
Where do these neurons synapse?
Lesser and least thoracic nerve
Mesenteric plexus
40
What is kidney medulla made of?
Where is the base of the pyramid?
Who many glomeruli are present in 1 kideny?
lobes (pyramids) 15-20 per kidney
Cortico-medullary border
1mln
41
Kidney functions
**filtration** – kidney glomeruli
**selective resorption and excretion** – kidney tubular system
**synthesis of renin** (regulates blood pressure via renin-angiotensin system)
**synthesis of erythropoietin** (regulates RBC production via ¯ [O2] produced by interstitial fibroblast of the kidney
**activates Vitamin D3**
42
What are the three parts of cortex?
renal corpuscles or glomeruli
cortical labyrinth
medullary rays
43
What are medullar rays?
Where do medullary rays originate?
Where do they end?
How many collecting ducts each renal papilla drains?
Collection tubules
Come from medulla and extend into cortex
Rounded renal papillae
20
44
What is kideny lobe?
What is kidney lobule?
A medullary **pyramid** + the **overlying cortex**
A group of nephrons that open into branches of the **same** main **collecting duct**
45
What separates cortex and medulla?
Arcuate vessels
46
What is nephron?
What is uriniferous tubule?
Glomerulus + kidney tubules
Nephron + collecting duct
47
Where are they found?
What is it?
Usuall capillary bed
Arterial capillary system
Venous portal system
CP = muscle
ACS = kideny
VPS = liver, pituitary
48
What is the purpose for arterial capillary system?
To control blood flow
49
What connect the arcuate and afferent arteries?
Interlobular arteries
50
What forms a visceral layer of bowman's capsule?
What forms a parietal layer of bowman's capsule?
What is between?
Podocytes
Simple squamous epithelium
Urinary space
51
What are two poles of Bowman's capsule
What is in vascular pole?
Urinary pole & Vascular pole
Afferent arterioles, efferent arterioles, extraglomerular mesangeal cells
52
What is the juxtraglomerular apparatus made of?
**Macula densa cells** (look like teeth in DCT)
**Extraglomerular mesangeal cells** (between a and e arteriole)
**Juxtaglomerular cells JG cells** (smooth muscle of a and e arteriole)
53
Are mesengial cells and endothelial cells separated by basement membrane?
What forms basement membrane?
No, they have direct contact. Communication? Diameter?
Produced by endothelial cells
54
What two components form a basal lamina inside of glomerulus?
Basal lamina of podocytes
Basal lamina of endothelium
55
What are the three layers of basal lamina in glomerulus (electron microscopy)?
**lamina rara interna** (capillary side)
**lamina densa** (very thick)
**lamina rara externa** (visceral layer side)
56
What is the name for secondary processes of podocytes?
Where are they locted on top of?
Pedicels
Lamina rara externa
57
Mesengial cells
Germ layer?
Function?
Can they change size?
What do they synthesize?
What proteins do they secrete?
Mesoderm (not bone marrow like other phagocytes)
Phagocytosis
Contractile = alter blood flow
Matrix and collagen
Prostaglandins and Endothelins
58
What is the protein that makes up the diaphragm between podoytes processes that control the slits?
Nephrin
59
What is the name of the border of PCT?
Staining?
Shape of cells?
What is absorbed?
What is elememinated?
Striated border (microvilli)
Eiosinophilic
Simple cuboidal epithelium
Most of Na and all glucose or amino acids
Toxins drugs
60
Three limbs of loop of henle?
Type of epithelial lining?
descending thin limb, Henle’s loop, ascending thin limb
Simple squamous
61
3 components of Juxtaglomerular apparatus (JGA)
Part of?
Function?
Macula densa / DCT /
Juxtaglomerular cells / on afferent and efferent / smooth muscle that produces renin
Extraglomerular mesangial cells / between afferent and efferent / connected to other by gap junctions ; ATII causes contraction of these cells
62
What type of epithelium is present in collecting duct?
What two types of cells can be distinguished in collecting duct under EM?
Cuboidal epithelium
**Principal cells** are lighter than **intercalated cells**.
63
Types of collecting tubules
**Collecting tubules**
**Medullary collecting tubules** (larger collection of several cortical collecting tubules)
**Papillary collecting tubules** (Dcuts of Bellini) \* lined with tall columnar principal cells only; open in area cribosa of renal papilla
Minor Calyxes
Major Calyxes
64
Layers of ureter
**Mucosa** (fibroelastic lamin propia; no glands; no muscularis mucosae)
**NO SUBMUCUSA**
**Muscularis**
**Adventitia** (UPPER 2/3 , Inner longitudinal, outer longitudinal LOWER 1/3 Inner longitudinal, middle circular, outer longitudinal)
65
Urinary bladder layers
**Mucosa**
transitional epithelium
fibroelastic lamina propria
**Muscularis**
IL MC OL
**Adventitia**
-fibroelastic adventitia is covered superiorly by peritoneum, forming a serosa
66
Female urethra lining (from bladder to end)
Male urethra lining (prostatic, membranous, penile)
**transitional** near the **bladder**, transitions to a **pseudostratified** and stratified columnar to a **stratified squamous**, **non-keratinized** at the distal **end**
**prostatic** (transitional) **membranous** (pseudostratified and stratified columnar) **penile** (pseudostratified and stratified columnar transition to simple squamous non-keratinized)
67
Similarities in female and male urethra
Vascular fibroelastic lamina propia
urethral glands (glands of Littre in male)
Internal sphincter IL OC
at urogenital diaphragm start voluntary control
68
What is K constant responsible for?
Area and permiability
69
How does the constriction of efferent artery affects filtration and reabsorption?
Increases filtration rate and reabsorption
70
What is the relationship between filtration and molecular radius/charge?
71
What is clearance?
The volume of plasma per minute from which all of a substance is removed
72
When clearance can be used to estimate glomerular filtration rate?
When molecule is:
freely filtered
not reabsorbed
not secreted
e.g. CIn = GFR
73
What other molecule can be used to measure the GFR except for inulin?
What are the problems associated with this molecule?
Creatinine
Ucr Overestimated because of secretion
Pcr Overestimated because of lab chemistry
74
What is
Filtration?
Reabsorption?
Secretion?
Excretion?
75
Two types of transport between tubules and capillaries
76
How sodium is transported in
Proximal tubule?
Thick ascending loop of henle?
Distal convoluted tubule?
Collecting duct?
77
How clorine is transported in
Proximal tubule?
Thick ascending loop of henle?
Distal convoluted tubule?
Collecting duct?
78
What is the result of the active sodium gradint?
Passive Cl- reabsorption
Passive urea reabsorption
79
How do
metabolic acidosis/alkalosis
hypokalemia/hyperkalemia
affect K+/H+ (pH) ions?
80
What causes shifts of K+ inside and outside of the cell?
81
How potassium is transported in
Proximal tubule?
Thick ascending loop of henle?
Distal convoluted tubule?
Collecting duct?
There are two types of cells in collecting duct. The principal cell and interacalated cells.
The principal cells has leak channels for potassium leading to higher
82
What affects potassium secretion?
Aldosterone
Intracellular potassium (stimulates adrenal gland to release aldosterone)
83
What is the effect of ... on kideny?
Furosemide, Thiazide, Amiloride
Potassium losing diuretics: Furosemide, Thiazide (inhibit Na+ absorption)
Potassium sparing diuretics: Amiloride (inhibit K+ leak)
84
What it is? Effects?
Bartter's syndrome (type 1)
Gitelman's syndrome
Which one contains: low potassium? Alkalosis? Polydisia (thirst)? Polyuria (excessive pee)? Hypertension /normal BP?
**Bartter’s syndrome (Type I)** Mutation of Na/K/Cl transporter in thick ascending limb.
**Gitelman's syndrome.** Mutation of Na/Cl transporter in distal tubule.
**Liddle’s syndrome (pseudohyperaldostronemia).** Increased number and open time of principal cell sodium channels.
85
Transport Maximum
The **highest rate** at which the renal tubules can **transfer** a substance either from the tubular luminal fluid to the interstitial fluid or from the interstitial fluid to the tubular luminal fluid.
86
How sodium is abosrbed in proximal tubules?
What transporter is involved?
90% of transport via SGLT2
10% of transport via SGLT1
87
Tx (reabsorption rate) =
equation
Tx (reabsorption rate) = GFR \* Px (filtered load) - V \* Ux (excretion rate)
88
What happens when concentration in filtrate exceeds Tm?
89
When sodium-glucose linked transporter-2 (SGLT2) inhibitors can be used?
Diabities
90
Why is urine flow increased with diabetes mellitus?
Enhanced Na reabsorption in the proximal tubule increases tubuloglomerular feedback (TGF)
Glucose in the tubule causes osmotic diuresis
91
Clearance vs. glucose and inulin concentration
92
What occurs if the secretion Tx exceeds the Tm?
93
Clearance vs. inulin and Para Aminohippurate (PAH) concentration
94
What is gout?
Treatment of gout?
A painful condition caused by the buildup of uric acid crystals in tissues and joints
95
Graph compare and contrast relative concentration over kideny tubules
96
Urea
What type of transport is used for urea transport in kidenys?
How Na+ reasborption affects urea transport?
How does urea excretion changes with urine flow?
What factors affect the urea reabosrbed?
Passive (reabsorption)
Increases it (water follows Na+)
Increases (less time for passive transport)
Tubular area, urea permeability, concentration gradient
97
How is the clearance of urea if affected by drinking / thirst?
Drinking increases clearance and decreases urea concentration in urine
Thirst decreases clearance and increases urea concentration in urine
98
Which layer does the urinary system originates from?
Intermediate mesoderm
99
Describe 3 intrauterine kideny systems
**Pronephros** cervical region; onyl during 4 week; nonfunctional
**Mesonephros** thoracolumbar region; 4wk-2mo; mesonephric duct (wolffian duct) stay
**Metanephros** 5wk; definative kideny
100
Mesonephros
Order of differentiation?
What is urogenital ridge? When it is formed?
When does it dissapear?
**Exeretory tubules** TO
**Renal corpuscle** (bowman's capsule and glomerulus) TO
**Mesonephric** (Wolffian) duct
It is future gonads and forms during 2nd month
2nd month except mesonephric ducts in males
101
Metanephros (definitive kideny)
When does it appear?
Where does it originate from?
Week 5
Buds off from mesonephric duct
102
What fors ureter, renal pelvis, major and minor calyces, and collecting tubules?
Where is that structure coming from?
Ureteric bud
Outgrowth of mesonephric duct
103
Filtration system
What is it made from? What is it induced by?
What is newly collecting tubule covered with?
Development of glomeruli?
From **metanephric mesoderm** included by **uteric bud**
Metanephric tissue cap
-\> renal vesicle -\> S-haped tubules -\> capillaries grow in -\> glomeruli
104
Kideny signalling function:
WT1 gene
Glial-derived neurotrophic factor (GDNF)
RET and MET receptors (for GDNF and HGF)
PAX2 and WNT4
**WT1 gene**
in mesenchyme, mantains competency to the induction by the ureteric bud
**Glial-derived neurotrophic factor (GDNF) and hepatocyte growth factor (HGF)**
in mesenchyme, stimulate branching and growth of the ueteric buds
**RET and MET receptors (for GDNF and HGF)**
In epithelium of the ureteric bud
**PAX2 and WNT4**
Conversion of the mesenchyme into epithelium
105
Congenital Polycystic Kidney
Pathogenesis?
Cyst formeation from collecting tubules
Recessive -\> renal failure in infancy or childhood
Dominant -\> renal failure in adulthood
106
Duplication of ureter
Cause?
Early splitting of the ureteric bud (partial or complete)
107
Why kidney ascends?
What happens as kidney ascends?
What happens to gonads as kideny ascends?
Decrease in body curvature and growth
Mesonephric system degenerates.
The descend
108
Positioning defects in kidneys
Horseshoe kideney
Kideny form in pelvis
109
Cloaca
Divides **urogenital sinus** (anterior) and the **anal canal** (posterior) by urorectal septum
110
Which strucutre alantois becomes?
Median umbilical ligament
111
What will the upper, peliv, and lower phallic part of urogenital sinus becomes?
Upper: bladder
Pelvic: prostatic and membranous part of urethra
Phallic part: different for sexes
112
Where do ureter migrate?
What part of ureter forms on the bladder?
Where do mesonephic duct move?
What do they become?
They are absorbed into the bladder wall and move cranially
Trigone area
Lower to enter urethra where prostate forms
Ejaculatory duct
113
What germ layer gives a rise to mesonephric ducts and ureters?
What germ layer gives a rise to mucosa of the urinary bladder?
What is mesodermal lining of the trigeon replaced with?
Mesoderm
Mesoderm
Endodermal epithelium
114
Bladder defects
Urachal fistula
Exstrophy of the bladder
Epispadias
**Urachal fistula**
Persistence of entire allantois results in urachal fistula
Local area of allantois results in urachal cyst
Upper part peristenace results in sinus
**Exstrophy of the bladder**
Ventral body wall defect: Mucosa is exposed
115
What is filtered load?
How to calculate filtered load?
The amount of substance that kidney filtrates.
Filtered load = GFR \* Px
116
What molecule is called a glomerular market?
Inulin
117
With reference to the kidney, what PAH stands for?
Para-aminohippuric acid (weak acid)
118
Which hydrostatic or osmotic variable changes as the plasma flow through glomerulus?
Oncotic pressure in capillary
119
How BUN/creatinine ratio would allow to distinguish between volume contraction (hypovolemia) vs. chronic renal failure.
Creatinine = not reabsorbed
BUN = reabsorbed
Volume contraction (hypovolemia)
Normal serum creatinine
Increase serum BUN
\>20 High BUN/creatinine ratio
Renal faliure
Increase serum creatinine
Increase serum BUN
Nomrla BUN/creatinine ratio
120
Whole kidney variables
C
[U]
[P]
V
GFR
RBF
RBF
C = Clearance
[U] = Concentration in urine
[P] = Concentration in plasma
V = Urine flow rate
GFR = Glomerular filtration rate
RPF = Renal plasma flow
RBF = Renal blood flow
121
Single Nephron variables
[TF]
[TF/P]x
[TF/P]in
[TF/P]x / [TF/P]in
[TF] = Concentration in tubular fluid
[TF/P]x = Concentration relative to plasma
[TF/P]x / [TF/P]in = Fraction of the filtered load remaining in tubular fluid or fractional excretion (\* this includes correction for water loss)
122
What is the name of the fluid that comes out of the capillary?
Ultrafiltrate because it has proteins removed.
123
Simple Plasma flow equation
Renal Plasma flow equation
Effective Plasma flow equation
Does PAH underestimate or overestimate RPF?
Q = dP / R
RPF = (V pah\*[U]pah)/d[P]pah
Underestimate (there is some left in the veins).
124
Clearance equation
Clearance ratio equation
C = Ux \* V / Px
C ratio = Cx/Cin
125
Glomerular filtration rate equation
GFR = Uin \* V / Pin = Cin
126
Filtration fraction equation
FF = GFR / RPF
127
What is the name of the spaces between foot processes of the podocytes?
Filtration slits
128
Free-water clearance equation
CH2O = V - Cosm
129
Renal blood flow equation
RBF = RPF / (1-Hct)
130
Reabsorption or secretion rate equation
Reabsorpton or secretion = Filtered load - Excretion
131
What does the Tm stands for?
Transport Maximum
132
What are examples of kidney vasoconstrictors?
Ware are examples of kidney vasodilators?
Vasoconstrictor
Sympathetic
Angiotensin II
Endothelins
Vasodialator
Prostaglandin
Nitric Oxide
Bradykinin
Dopamine
ANP
133
What are two mechanisms for autoregulation?
Autoregulation
Mediated by strech opening Ca2+ channels and causing contraction
Affects more afferent arteriole
Tubuloglomerular feedback (TGF)
Macula densa cells signal (ADP) due to higher flow.
ADP binding to JG cells.
Relaxation of afferent arteriole
134
How dopamine can be used to treat hemorrhage?
At low levels, dopamine dilates cerebral,
cardiac, splanchnic, and renal arterioles, and it
constricts skeletal muscle and cutaneous arterioles.
135
Effects of Angiotensin II on afferent/efferent arteriole
Low concentration?
High concentration
Efferent arteriole is more sensitive to A II
Low A II =\> Efferent constriction =\> (+) GFR
High A II =\> Afferent constriction =\> (-) GFR
136
How do prostaglandins protect flow in kidneys?
How do RAAS protects flow in kidneys?
How these protection mechanisms can be disturbed?
Protect from constriction / ACE inhibitor
Protect from dilation / NSAID
137
What two systems that balance each other in kidney are activated during hemorrhage?
RAAS and prostaglandins
138
BNP effect
Dilation of afferent arteriole (more significant)
Constriction of efferent arteriole
139
What is the name of the transporter that is responsible for glucose/Na+ coortransport in PCT?
What is the name of the glucose transporter present in basolateral membrane?
SGLT (SGLT2 90%; SGLT1 10%)
GLUT I & GLUT II
140
What factors shifts K+ into cells?
What factors shift K+ outside of cells?
Insulin (Na+/H+ exchanger +)
b-agonist (Na+/K+ ATPase +)
Aldosterone (Na+/K+ +)
Hyperosmolarity
Exercise
Cell death
141
What are two effects of aldosterone in DCT?
How aldosterone affects principal cells?
Activation of Na+ channels and
Activation of Na+/K+ ATPase on basolateral side
Aldosterone stimulates H+ secretion
142
What mechanisms regulate Na+ absorption?
Sympathetic
Atriopeptin (ANP)
Starling forces
RAAS
143
What is the function of intercalated and principal cells?
What channels do these cells contain?
Principal
Na+ absorption
K+ secretion
Na+ and K+ channel
Na+/K+ ATPase on basolateral
Intercalated
K+ reabsorption
H+ secretion
144
Name the condition where glucose is released to urine.
When can it occur?
Glucosuria
Can occur:
DM
Pregnancy (up GFR)
Congenital abnormality (SGLT)
145
How does the probenecid affect penicillin?
Penicillin uses the same transporter as PAH in kideny. Probenecid inhibits this transporter.
146
What shifts in K+ would acidemia or alkelemia produce?
In alkelemia, H+ leave cells, and K+ enter cells producing hypokalemia
In acedemia, H+ enter cells, and K+ leave cells producing hyperkalemia
147
Where are these ions absorbed?
PCT/DTL/ATL/DCT/CD
Na+
K+
PO4-
Ca2++
Mg2++
Urea
Na+ = 67% / 0 / 25% / 5% / 3% = \<0.4%
K+ = 67% / 0 / 20% / low K+ diet / secreted
PO4- = 70% / 15% / 0 / 0 / 0 = 15%
Ca2+ = 67% / 0 / 25% / 8% / 0 = 1%
Mg2+ = 30% / 0 / 60% / 5% / 0 = ~5%
Urea = 50% / (thin) -50% / 0 / 0 / 40%\* (ADH) = 1%-110%
148
What affects potassium secretion to late distal convoluted tubule?
Dietary K+
Aldosterone
Acid-base balance
Flow rate
Luminar anions
149
What is the difference in permeability between thin ascending and descending limb?
Descending is permeable to H2O, NaCl, Urea
Ascending is only permeable to NaCl
150
What is an example of K+ sparing diuretic?
Inhibit K+ channel
Amiloride
Triamterene
Inhibit aldosterone
Sprionolactone
151
Three types of diuretics
Examples
Loop diuretics (e.g. furosemide)
Thiazide diuretics (e.g. thiazide)
K+-sparing diuretics (e.g. amiloride)
152
What are three effects of ADH?
Fusion of H2O channels (V2-cAMP mediate) in late DCT and CD (cortical and medulla)
Inhibition of 2Cl-/K+/Na+ channels in thick AL
Increase in UT1 urea channels in CD (medulla)
153
SIADH
Abbreviation?
What is it?
Treatment?
Syndrome of inappropriate ADH
Excess of ADH
Demeclocycline (ADH inhibitor)
154
What is the target cell for ADH?
Principal cell
155
Central Diabetes Insipidus
Nephrogenic Diabetes Insipidus
Lack of ADH, dDAVP analog replacement
Lack of response to ADH, Thiazide diuretics
156
How PTH regulates phosphate?
Sign of high phosphate excretion?
How PTH regulates Calcium?
PTH inhibit phosphate reabsorption in PCT (cAMP mediated). High phosphate/cAMP in urine is a sign of PTH action.
PTH increase Ca++ reabsorption in distal convoluted tubule (cAMP mediated).
157
How thiazide diuretics action differs on Na+/Ca++ in distal convoluted tubule?
Transport in DCT of Na+ and Ca2+ is not linked
Na+ absorption inhibited
Ca+ absorption increased
158
What is absorbed in early promixal tubule?
How absorption of Na+ differs from early to late proximal convoluted tubule?
Type of absorption in proximal convoluted tubule?
How does angiotensin affect PCT?
Glucose, Amino acids, Phosphate, Lactate, Cirtrate
Early: basolateral Na+/K+ driven; Na+/H+ (Na+ enters with HCO3-)
Late: Na+/Cl- driven
Isosmotic
Stimulates Na+/H+ exchange
159
What type of Na+ transport is present in ascending limb of thick ascending limb?
What can leak and what is the importance of it?
Na+/K+/2 Cl-
K+ leaks creating lumen-positive potential and driving Ca2+ and Mg2+ into cells
160
What does the reabsorption of urea follow?
Where is urea permable?
What mode of transport is urea using?
Water reabsorption
In proximal tubule (50% reabsorbed)
In medullary collecting duct (UT1 -- ADH regulated)
Passive transport
161
What type of transport is present in Early Distal Convoluted Tubule?
Reabsorption of NaCl without water (dilutio)
162
What determines the flow of water via paracellular route?
What is the pattern of the resistance to flow via a paracellular route?
Tight junction proteins (claudins and occludins)
Resistance increases
163
What causes renin release
Stretch in afferent arteriole
NaCl delivery
Sympathetic
164
Downstream effect of angiotensin II
Constriction of arterioles
Brain thirst and ADH release
NE release
Aldosterone production
165
Ouabain function
Inhibit Na+/K+ ATPase
166
Function of allopurinol
Function of probenecid
Prevents synthesis (xantinine oxide inhibitor)
Prevents reabsorption (increases secretion)
167
Two mechanisms that are used in formation in hypertonic urine
ADH and an intersititial osmotic gradient
168
Psychogenic Polydipsia
Drinking too much water
169
What transporters are used for urea transport?
170
Where does the osmolarity is sensed?
Paraventricular and supraoptic neurons
171
What are the downstream effects of ADH?
Bidning to V2 receptor
Kinease cascade
AQP recycling
172
What is?
Diuresis
Osmotic Diuresis
Water Diuresis
Antidiuresis
Diuresis (V \> 1 ml/min) -- low flow
Osmotic Diuresis -- flow with too much salt
Water Diuresis -- flow with too much water
Antidiuresis (V \< 0.5 ml/min) -- antiduresis
173
How high or low ADH affects urea, salt, and water reabsorption?
174
What is the compositon of urine?
175
Types of tracers
176
Equations for:
Intracellular fluid Volume
Blood Volume
Interstitial Fluid Volume
Intracellular fluid Volume = TBW
Blood Volume = PV/(1-hct)
Interstitial Fluid Volume = EFV - PV
177
How is water distributed?
178
Darrow Daigram
Overhydration
Careless over administration of saline
179
Darrow Daigram
Hypotonic Overhydration
Compulsive water drinking
180
Hypertonic Overhydration
Drinking sea water
181
Darrow Daigram
Isotonic Dehydration
Hemorrage
182
Hypertonic Dehydration
Lost in the desert without access to water
Diabetes insipidus (lack of ADH)
183
What is hypernatremia?
Rise in sodium levels
184
How does the hypothalamus responds to changes in osmolarity?
ADH and thirst
185
What is Glomerulotubular (GT) Balance
186
Hypoaldosteronemia
Hyperaldosteronemia
characteristics?
Adrenal insufficiency (Addison’s disease)
Acidosis
Hyperkalemia
Hypotensin (salt wasting)
Alkalosis
Hypokalemia
Hypertension
(usually not overt volume expansion)
187
Where is the action of
Aldosterone?
ANP?
ADH?
Angiotensin?
