pnb 2275 exam 4
In male 5alpha-reductase deficiency patients (lack enzyme for the formation of dihydrotestosterone): pick all that apply 1.female external genitalia are present 2.female internal genitalia are present 3.female gonads are present 4.male external genitalia are present 5.male internal genitalia are present 6.male gonads are present
1 5 6
if ADH present in the collecting duct urine excreted will be close to what osmolarity
1200 mOsm
loop of henle deep in medulla reaches what osmolarity
1200 mOsm / L
average adult gfr
125 mL/min 180 L/day
NaHCO3- and Na organic salt reabsorption
1st half of PCT reabsorbed co transport with AA, glucose counter transport with H+
GFR is 115 mL/min, Tm for glucose is 287.5 mg/min. Plasma glucose concentration is 1 mg/mL. What is the renal threshold for glucose? 115 mg/ mL 2.5 mg/ mL 1 mg/ mL None of the above
2.5 mg/ mL
What is the clearance of a substance when its concentration in the plasma is 10 mg/dL, its concentration in the urine is 100 mg/dL, and urine flow is 2 mL/min? 2 mL/min 10 mL/min 20 mL/min 200 mL/min Clearance cannot be determined from the information given.
20 mL/min
_____% filtrate reaches the descending loop of henle @ this pt what is osmolarity
30 300 mOsm /L
body must have obligatory water loss of about
600 mOsm of ions or 0.5L per day
break down of filtration fraction
80% of plasma flowing into afferent exits through efferent 20% filtered in glomerulus and 19% of this is reabsorbed only 1% of what is filtered is excreted
A man abuses testosterone injections, so blood work will show a high amount of testosterone, what else will we see? A. increased estrogen, decreased LH, decreased FSH B. increased DHT, increased estrogen, increased FSH C. increased DHT, increased LH, increased FSH D. increased estrogen, decreased LH, decreased DHT E. decreased DHT, decreased FSH, decreased LH
A
Glucagon stimulates gluconeogenesis. primarily targets the liver. targets skeletal muscle directly. A and B A, B, and C
A and B
if you are very hydrated (choose all that apply) A) decreased blood osmolarity B) increased blood osmolarity C) high secretion of ADH D) low secretion of ADH E) insertion of water channels into collecting duct F) removal of water channels from collecting duct G) low reabsorption of water by osmosis H) high reabsorption of water by osmosis I) production of a large volume of urine J) production of a low volume of urine
A d f g i
enzyme that converts ANG1 --> ANG2
ACE
What effect would a decrease in blood pH have on the amount of potassium ion in the urine? A) an increase in the amount of potassium in the urine B) a decrease in the amount of potassium in the urine C) no effect on the amount of potassium in the urine
B) a decrease in the amount of potassium in the urine
which would be a response to high plasma glucose in type 1 diabetes? A) Decreased ketone production B) Decreased thirst C) Increased blood pressure D) Increased ventilation E) Decreased ADH
D
After ingestion of carbs in an insulin deficient diabetic what will occur: A) Protein degradation B) Fat synthesis C) Gluconeogenesis D) Increased glycolysis E) A and C think of other symptoms of type 1 diabetes
E also will see glucose sparing, polyphagia (brain thinks you are starving), hyperglycemia, glucosuria which will draw more water out - pee frequently - dehydrated - bad circulation, tissue loss because continued breaking down of muscle and adipose, increased ventilation, acidic urine and hyperkalemia normal healthy individual would experience B and D
if filtration is less than or equal to tubular maximum then what can be said about reabsorption and excretion of this substance if we increase the GFR then what will happen in terms of renal threshold
F=R, E=0 because everything will be reabsorbed Increase GFR --> renal threshold reached sooner (shift left on graph)
inulin clearance =
GFR
filtration =
GFR * concentration of substance in plasma
basolateral membrane glucose transporter found in intestine, liver, renal cells facilitated diffusion insensitive to insulin
GLUT2
glucose channel found in skeletal and cardiac muscle / adipose tissue that is sensitive to insulin
GLUT4
Increase exercise increase which channel expression in skeletal muscles
GLUT4 *** this occurs even without insulin even though these channels are insulin dependent in resting skeletal muscle
in intercalated cells K+ is moved into cell from tubule in exchange for
H+ k INto INtercalated cell (exchange h)
renal secretion mostly
H+ and K+ in DCT
Which of the following would cause an increase in net filtration pressure? Increase in fluid pressure in Bowmanâ s capsule. Increase in blood osmotic pressure. An increase in the medullary osmotic gradient. Constriction of afferent arteriole. Increase in glomerular blood pressure.
Increase in glomerular blood pressure
Which of the following statements concerning the hormone atrial natriuretic peptide is FALSE? A) It is produced by cells in the heart B) It promotes sodium loss at the kidneys C) It reduces the sensation of thirst D) It suppresses ADH secretion E) It increases aldosterone secretion
It increases aldosterone secretion THINK opposite of renin
Cells that secrete testosterone
Leydig cells
in type 2 diabetes more or less glucose transporters are expressed
MORE - help reabsorption Tm and renal threshold are higher
Which of the following statements are true? (Choose all that apply) Macula densa cells found in the distal tubule sense changes in filtrate osmolarity. Granular cells, specialized smooth muscle cells, is part of the juxtaglomerular apparatus. Juxtaglomerular apparatus is important in regulating GFR. Adenosine is released from macula densa cells to constrict afferent arteriole when GFR is increased.
Macula densa cells found in the distal tubule sense changes in filtrate osmolarity. Granular cells, specialized smooth muscle cells, is part of the juxtaglomerular apparatus. Juxtaglomerular apparatus is important in regulating GFR. Adenosine is released from macula densa cells to constrict afferent arteriole when GFR is increased.
in principal cell K+ is moved out of the cell into tubule in exchange for
NA+
hormone that promotes sodium and water excretion
NAP
active transport of sodium occurs where
Na+ actively pumped (reabsorption) in thick ascending limb of loop of Henle
Of the following substances, which has the highest renal clearance in a normal healthy person? glucose bicarbonate (HCO3) inulin PAH (para-aminohippurate)
PAH (para-aminohippurate)
if wanted to measure renal blood flow you would use because
PAH clearance because all PAH escaping filtration is secreted in tubule
renal glucose reabsorption - which transporters expressed in PCT vs descending loop of henle
PCT - SGLT2 - 90% Descending Loop - SGLT1 -10%
If filtration is greater than tubular maximum then what can be said about reabsorption and excretion
R = Tm E = F - Tm
channel on apical membrane responsible for glucose and sodium cotransport
SGLT1
The clearance of substance X is 200 ml/min. The clearance of inulin is 125 ml/min. What do you conclude? Substance X is filtered and secreted. All of substance X is reabsorbed. Substance X is filtered and reabsorbed. Substance X is not filtered, reabsorbed, or secreted. The clearance of substance X is equal to the glomerular filtration rate.
Substance X is filtered and secreted.
Consider the myogenic mechanism for autoregulation of glomerular filtration rate. If renal blood pressure rises, The macula densa will secrete K+ ions in response. The collecting duct will dilate in response. The afferent arteriole will constrict in response. Autoregulation will cause the renal blood pressure to rise more via positive feedback. The afferent arteriole will dilate in response.
The afferent arteriole will constrict in response.
following Na+ active transport reabsorption out of tubule lumen
anions move with gradient paracellular and transcellularly then osmosis of water with gradient transcellularly and paracellularly then decreased volume --> other positive solutes move ONLY transcellularly
order of membranes reabsorbed molecules pass through
apical basolateral peritubular capillary endothelium
ADH will result in aquaporins being inserted on the
apical membrane
transcellular water channels in the membrane
aquaporins
Normally, the clearance for glucose is close to zero. about half the GFR, or 65 ml/min. the GFR, about 125 ml/min. equal to the clearance for creatinine, about 1000 ml/min. greater than the clearance for inulin.
close to zero.
in myogenic response: increase blood pressure
constrict afferent arteriole
85 % of the bodies nephrons are
cortical mostly reabsorption peritubular capillaries only
if resistance increases GFR will
decrease
if there is an SGLT 2 inhibitor what will happen to the Tm and renal threshold for glucose
decrease
hyperventilation
decrease PCO2, increase pH
if dilate the afferent arteriole
decrease resistance increase filtration
Atrial natriuretic peptide (ANP) effect
dilate decrease blood pressure increase GFR
in myogenic response: decrease blood pressure
dilate afferent arteriole
colloid osmotic force
due to proteins in plasma NOT IN BOWMANS
renal clearance
excretion rate of substance / [substance]plasma
absence of MIS what genitalia develop
female internal develops
filtration barrier of glomerulus resulting filtrate does not contain? pressure?
fenestrated capillary epithelium basal lamina podocyte pores PROTEIN FREE FILTRATE ~10 mm hg pressure
excretion =
filtration - reabsorption + secretion
estrogen secreted during
follicular - granulosa cells luteal - corpus luteum
comparative male part of clitoris
glans of penis
which receptor is always expressed regardless of insulin presence
glut2
glucagon promotes glycogenolysis gluconeogenesis ketogensis which does not occur in muscles
glycogenolysis - only in liver!!
inhibins secreted from effect
gonads inhibit release of FSH
modified smooth muscle cells of AFFERENT arteriole that contract and secrete renin
granular cells
Hemhorrage vs dehydration in terms of secretions
hemorrhage - aDH and aldosterone secreted dehydration - only ADH , dont want to retain NA+
PAH renal clearance
high
ions secreted in DCT K+, H+, NH4+, creatinine, penicillin therefore they have high or low renal clearance
high
creatinine is endogenous which makes it useful using its clearance value to ESTIMATE GFR but estimate will be slightly
higher because a small amount is secreted into urine overestimate 5-10%
which condition will aldosterone be released hyper or hypokalemia
hyperkalemia high plasma K+ aldosterone will rebsorb Na+ in exchange for K+ secretion (short loop response)
Which of the following symptoms would you NOT expect to observe in a person suffering from untreated type I diabetes mellitus? hypotension hypoglycemia glucosuria ketoacidosis thirst and polydipsia
hypoglycemia
when does clearance of a substance = GFR
if the substance is freely filterable at the glomerulus not secreted or reabsorbed or broken down in tubules
hexokinase
in presence of insulin (fed state) glucose moved into hepatocytes and converted to glucose-6-phosphate maintains gradient and keeps intracellular glucose levels low
insulin effects on liver rapid, intermediate, delayed
increase glycolysis glycogenesis fat (lipogenesis) and protein synthesis intermediate
insulin effects on muscle and adipose rapid, intermediate, delayed
increase glucose transport rapid
increasing secretion will have what effect on renal clearance
increase renal clearance
if constrict the afferent
increase resistance decrease filtration more blood flow to other organs
The most potent stimulus for vasopressin release is
increased PLASMA osmolarity
in both types of diabetes after eating what is true about plasma glucose
increases and never comes down
aromatase
increases estrogen, secreted by sertoli cells
type 1 diabetes mellitus
insulin deficient due to destruction of pancreatic beta cells concordance 33% genetic defect MHC chromosome 6
type 2 diabetes mellitus
insulin resistant 100% concordance NOT JUST DUE TO LIFESTYLE
what cells of the collecting duct are pH dependant for variable H+ and bicarbonate transport
intercalated cells
hormone signal to develop male external vs internal genitalia
internal - testosterone external - DHT
what substance does clearance = GFR
inulin
ascending loop of henle reabsorption of
ions
where is renin secreted
kidneys
angiotensinogen secreted from
liver
how does vomiting effect pH
loss of H+ --> alkalosis
how does diarrhea effect pH
loss of bicarbonate --> acidosis
glucose renal clearance
low
high or low BP will signal renin release
low
Which of the circumstances would result in aldosterone release? High blood pressure Low Blood Pressure Hypokalemia Hyperkalemia Hemorrhage Dehydrated Diet with low salt Diet with high salt
low blood pressure hyperkalemia hemorrhage diet with low salt
3 things that trigger ADH release
low blood pressure low blood volume increased PLASMA osmolarity
what triggers aldosterone release
low blood pressure through renin angiotensin or increased ECF [K+]
modified epithelial cells with osmoreceptors in DISTAL CT
macula densa
contractile cells that regulate glomerular filtration
mesangial cells
Glycogenolysis
muscle and liver glycogen to glucose
E<F
net reabsorption
E>F
net secretion
resting skeletal muscle and adipose in presence of insulin vs. not
no insulin no glucose transport insulin --> lipogenesis and inhibited lipase
PAH has a very high clearance because it is
not reabsorbed and it is secreted
follicular phase hormone secreted and by
ovarian cycle estrogen granulosa cells
female second meiotic division during
ovulation
insulin secreted from
pancreas (beta cells)
part of the collecting duct permeable to urea
papillary duct
Urea reabsorption in PCT
passive transcellular or paracellular
comparative male part of labia minora
penis shaft
relative values for ph pi pfluid
ph = 50 mm hg these 2 oppose filtration: pi = 10 mm hg pfluid = 15 mm hg
to estimate GFR of creatinine need
plasma sample and 24 hour urine collection
what cells of collecting duct are ADH sensitive to water reabsorption and aldosterone sensitive to Na+ reabsorption
principal cells
After ingestion of carbohydrates in an insulin-deficient diabetic, __________ would happen. protein degradation fat synthesis glycogenesis increased glycolysis
protein degradation
Juxtaglomerular or tubuloglomerular Apparatus provides a feedback mechanism to regulate GFR. is composed of the Bowman's capsule and glomerulus only. is a kidney filtration barrier. is responsible for myogenic response. plays an important role in reabsorption process.
provides a feedback mechanism to regulate GFR.
1st meiotic division for male and females occurs at
puberty
GnRH release from gonads must be
pulsatile
renal clearance will be low when
reabsorption exceeds secretion and filtration think glucose
nephron consists of
renal corpuscle (glomerulus and bowmans) and renal tubule
Primary targets for insulin action include all of the following EXCEPT cellular protein synthesis hepatic glycogen synthesis renal glucose reabsorption adipose lipogenesis skeletal muscle glucose absorption
renal glucose reabsorption
if given hematocrit and renal plasma flow how would you calculate renal blood flow
renal plasma flow / % thats plasma (aka 1.0-hematocrit)
plasma concentration at which particular molecule will appear in urine is known as
renal threshold
enzyme that converts Angiotensinogen to ANG1 secreted by
renin granular cells in afferent arteriole
the vasa recta parallel to the ascending loop in juxtamedullary nephrons takes in blood is flowing up or down
salts blood is flowing down
comparative male part of labia majora
scrotum
renal compensation for acidosis transport involved
secrete H+ (Na+ / H+ exchanger) reabsorb HCO3- via symport
LH effects on leydig cells
secrete testosterone - negative feedback loop which inhibits GnRH, LH, FSH
sympathetic neurons have what effect of Ph and GFR
sense drop in blood pressure, stress and DECREASE GFR and Ph
if aldosterone secreted in DCT then more ______ reabsorbed
sodium
maturation of sperm
spermiogenesis
renin-angiotensin-aldosterone system
stimulus: decreased BP juxtaglomerular cells of kidneys to secrete renin which converts angiotensinogen (inactive secreted from liver) to angiotensin I (active) which is then converted into angiotensin II by ACE -ANG II stimulates the adrenal cortex to secrete aldosterone - aldosterone = Na+ reabsorption and increased blood pressure
In most renal diseases GFR is _____________ this is detected by ________ creatinine clearance or more frequently by _________ Plasma creatinine
substantially reduced diminished creatinine clearance elevated plasma concentration
Sertoli cells
support spermatogenesis and secrete androgen binding protein, inhibin, MIS, aromotase
Na+ in tubule lumen is reabsorbed via (take into account both membranes)
transcellular active transport on BASOLATERAL side variety of transporters on apical
Protein reabsorption in PCT
transcytosis
when GFR is high - flow through tubule increases and macula densa osmoreceptors sense ions - paracrine feedback to constrict arteriole and reduce flow to decrease GFR
tubuloglomerular feedback
if blood pressure is decreased
vasoconstriction increase thirst ADH released
when salt is ingested what is true about volume and plasma osmolarity will vasopressin be released?
volume - stays same plasma osmolarity increases yes
Angiotensin II effect on arterioles adrenal cortex
want to INCREASE blood pressure constricts vessels and release aldosterone
descending loop of henle reabsorption of
water
if ADH secreted in DCT then more ______ reabsorbed
water
the vasa recta parallel to the descending loop in juxtamedullary nephrons takes in blood is flowing up or down
water blood is flowing up
Adenosine causes vasoconstriction and NO causes vasodilation. When GFR increases, Macula Densa will release which paracrine as part of the TGF response: A. Adenosine B. NO
when GFR increases we want **feedback loop** to decrease GFR constrict - increase BP - decrease GFR therefore adenosine
tubuloglomerular feedback
when GFR is high - flow through tubule increases and macula densa osmoreceptors sense ions - paracrine feedback to constrict arteriole and reduce flow to decrease GFR
myogenic response
when blood pressure increases - constrict afferent arteriole or when blood pressure decrease - dilate afferent arteriole in order to keep constant GFR between 80-180 mm Hg
presence of testosterone what genitalia develop
wolffian duct --> develops male internal
insulin
anabolic hormone decreases blood glucose
tubular maximum (Tm)
The maximum amount of a substance that the renal tubular cells can actively reabsorb saturation of mediated transport
Once the blood concentration of substance Y exceeds the transport maximum (Tm) for reabsorption Y will always be secreted. Y will no longer be filtered. The amount of Y appearing in filtrate will increase over that in the blood. Y will appear in the urine. Y will increase in the blood.
Y will appear in the urine
Type A intercalated cells
acidosis pumps on apical side, secrete h+
Which of the following is NOT true about angiotensin II? stimulates thirst elevates blood pressure activates parasympathetic output is a potent vasoconstrictor increases cardiac output
activates parasympathetic output
3 variables influencing Ph (glomerulus hydrostatic pressure)
afferent and efferent arteriole resistance arterial pressure
aldosterone vs ADH receptors
aldosterone is a cytoplasmic receptor
Type B intercalated cells
alkalosis pumps on basolateral side
glucagon secreted by
alpha cells of pancreas