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