UTA PATHO PRACTICE TIPS EXAM QUESTIONS AND
ANSWERS GRADED A+
✔✔kidney fxn - ✔✔- excretion of metabolic waste products
- maintenance of H2O bal
- reg of acid/base bal
- BP reg
- secretion of erythropoietin which stim growth of RBCs
- activates vit D: which assists w/ absorption of Ca in intestines: vit D received from
food, absorbed in skin which is then turned into a precursor of vit D by UV light & is
transported to kidney where it is converted to active form of vit D, calcitriol. Calcitriol is
resposible for assisting w/ absorption of Ca in intestines, promoting rel of Ca from bone,
and decreasing renal Ca excretion
- glucose reg: kidneys help to maintain glucose bal by completing gluconeogenesis from
amino acids by taking up glucose from circulation & reabsorbing glucose from
glomerular filtrate. kidneys absorb glucose in proximal tubule by sodium glucose
cotransporter 2 protein which helps to ensure adequate glucose is available during
fasting when they become saturated, glucose spills over into the urine
✔✔nephron structure - ✔✔- two types of nephrons: cortical nephron & juxtamedullary
nephron
- three main parts:
= glomerulus: collection of capillaries which receives bl from renal artery & is resp for
filtering bl
= bowmans capsule: partially encases glomerulus & extends to form tubule system
= tubule system
✔✔proximal tubule - ✔✔- comes off of the bowmans capsule & is recipient of filtrate
which flows from glomerulus into bowmans capsule
- reabsorbs al glucose, amino acids, most of the bicarb, Na, Cl, phosphate, K & H2O
- when stim by parathyroid hormone will excrete phosphate
- site of action for angiotensin II which stim Na, H2O, & bicarb reabsorption
✔✔descending loop of henle - ✔✔- extends from proximal tubule
- impermeable to Na
- passively reaborbs H2O
- concentrates urine
✔✔ascending loop of henle - ✔✔-extends from descending loop of henle
- reabsorbs Na, K, & Cl
- induces reabsorption of Mg & Ca
- impermeable to H2O
- makes urine more dilute
✔✔distal convoluted tubule - ✔✔-extends from the ascending loop of henle
,- actively reabsorbs Na
- impermeable to H2O
- causes urine to be more dilute
- parathyroid increases Ca reabsorption
✔✔collecting tubule - ✔✔- extends from distal convoluted tubule & connects renal
pyramids
- reabsorbs Na in exchange for K & hydrogen
✔✔juxtaglomerular apparatus - ✔✔- located just proximal to renal corpuscle b/w
afferent & efferent arterioles & where distal tubule loops up & makes contact w/ afferent
arteriole
- collection of cells consisting of juxtaglomerular cells, macula densa, mesangial cells
- located in walls of afferent arterioles
- monitor renal pressure & help to maintain normal GFR through release of renin
- when renal perfusion is decreased these cells are responsible for releasing renin to
help increase GFR
- end result of renin is relase of angiotensin II which constricts efferent arteriole thereby
increasing press to glomerulus
- macula densa is a grp of epithelial cells located in distal convoluted tubule that are in
close contact w/ afferent & efferent arterioles. They help to regulate GFR.
-mesangial cells are located in section b/w afferent & efferent arterioles & among
glomerular capillaries. fxn as macrophages & are able to contract to regulate bl flow of
glomerular capillaries
✔✔renal blood flow - ✔✔- 1000-1200 ml of bl per min
- 20% of plasma is filtered out of capillaries & enters bowmans capsule; filtrate then
enters proximal tubule at a rt of 125ml/min which is known as GFR
- 80% pf plasma is not filtered into bowmans capsule but instead flows out fo glomerular
space & into efferent arterioles; efferent arterioles divide into millions of capillaries that
surround tubules & are called peritubular capillaries; network in conjunction w/ ep cells
of tubules is resp for solute exchange & H20 regulation
- renal arteries branch of the aorta, go into kidneys & become afferent arteriole of
glomerulus & form glomerular arterioles
- network then forms efferent arteriole which then forms peritubular capillaries which
eventually connect w/ venous system & then w/ IVC
✔✔NSAIDs and Renal Function - ✔✔- block production of renal protective
prostaglandins & can cause kidney injury, Na retention & edema
✔✔Angiontensin II - ✔✔- constricts mainly efferent arterioles in glomeruli
- causes an increase in GFR & glomerular press
✔✔ACE inhibitors - ✔✔- block action of angiotensin II on efferent arterioles & have a
renal protective quality in DM b/c it decreased press w/in glomeruli
, ✔✔Regulation of renal blood flow - ✔✔- affect amnt of bl which flows to kidneys & rt of
filtration
- decrease in art bl press or a decrease in EABV causes a decrease in renal perfusion
- decrease in renal perfusion causes filling pressure of glomerular arterioles to decrease
which in turn decreases GFR which l/d a decrease in fluid & Na in distal tubule
- decrease is sensed by JGA which then sends signals to afferent arterioles to relax
which increases flow of bl to glomeruli & JGA releases more renin which converts
plasma protein angiotensinogen to angiotensin I which then passes through lungs &
stim release of angiotensin II which stim vasoconstriction of efferent arterioles to help
increase glomerular back press & increases GFR
- angiotensin II also is resp for stim release of aldosterone which controls Na regulation
& signals collecting ducts in nephron to reabsorb Na. increased Na load l/d increase in
H2O retention & ult an increase in bl vol, BP, & GFR
✔✔Infants & renal system - ✔✔- urinary system dev during 3rd wk gestation
- glomeruli dev in stages & devmnt cont through ninth mo of gest
- kidneys ascend to sacral area around 6 wks gest, 3rd lumbar area by 3rd mo of gest &
to first lumbar area @ 9 mo
- @ birth kidneys occupy a lrg portion of post abd wall & ureters are shorter than an
adult
- all nephrons are present @ birth & # never increases
- urine form & excretion begin by 3rd mo of gest & contributes to amniotic fluid
- imm after birth renal bl flow & GFR increase d/t a decrease in vas resistance & need to
fxn now that placenta is detached
- renal vas resistance is high in newborns & infants b/c of increases levels of renin
- GFR reaches adult levels by 2
- infants have more dilute urine up to age 6mo
-kidneys are less resp to ADH
- urea excretion is low d/t high anabolic state & use of protein for growth
- tubular system is immature in infants & this r/s in a decreased ability to excrete K,
reabsorb bicarb or buffer hydrogen w/ ammonia
✔✔Aging and Renal Function - ✔✔-hypertrophy
- renal bl flow & GFR decrease
- number and size of nephrons decrease
- tubular atrophy
- glomerular cappillaries become sclerotic
- reduces ability to excrete urine
- specific gravity is lower
- glucose, bicarb, & Na are not efficiently reabsorbed
- hyperK is more common
- drugs are not cleared as easily
- inability to activate Vit D so Ca absorption is impaired
- freq, urgency, nocturia
✔✔nephrolithiasis - ✔✔- kidney stones
ANSWERS GRADED A+
✔✔kidney fxn - ✔✔- excretion of metabolic waste products
- maintenance of H2O bal
- reg of acid/base bal
- BP reg
- secretion of erythropoietin which stim growth of RBCs
- activates vit D: which assists w/ absorption of Ca in intestines: vit D received from
food, absorbed in skin which is then turned into a precursor of vit D by UV light & is
transported to kidney where it is converted to active form of vit D, calcitriol. Calcitriol is
resposible for assisting w/ absorption of Ca in intestines, promoting rel of Ca from bone,
and decreasing renal Ca excretion
- glucose reg: kidneys help to maintain glucose bal by completing gluconeogenesis from
amino acids by taking up glucose from circulation & reabsorbing glucose from
glomerular filtrate. kidneys absorb glucose in proximal tubule by sodium glucose
cotransporter 2 protein which helps to ensure adequate glucose is available during
fasting when they become saturated, glucose spills over into the urine
✔✔nephron structure - ✔✔- two types of nephrons: cortical nephron & juxtamedullary
nephron
- three main parts:
= glomerulus: collection of capillaries which receives bl from renal artery & is resp for
filtering bl
= bowmans capsule: partially encases glomerulus & extends to form tubule system
= tubule system
✔✔proximal tubule - ✔✔- comes off of the bowmans capsule & is recipient of filtrate
which flows from glomerulus into bowmans capsule
- reabsorbs al glucose, amino acids, most of the bicarb, Na, Cl, phosphate, K & H2O
- when stim by parathyroid hormone will excrete phosphate
- site of action for angiotensin II which stim Na, H2O, & bicarb reabsorption
✔✔descending loop of henle - ✔✔- extends from proximal tubule
- impermeable to Na
- passively reaborbs H2O
- concentrates urine
✔✔ascending loop of henle - ✔✔-extends from descending loop of henle
- reabsorbs Na, K, & Cl
- induces reabsorption of Mg & Ca
- impermeable to H2O
- makes urine more dilute
✔✔distal convoluted tubule - ✔✔-extends from the ascending loop of henle
,- actively reabsorbs Na
- impermeable to H2O
- causes urine to be more dilute
- parathyroid increases Ca reabsorption
✔✔collecting tubule - ✔✔- extends from distal convoluted tubule & connects renal
pyramids
- reabsorbs Na in exchange for K & hydrogen
✔✔juxtaglomerular apparatus - ✔✔- located just proximal to renal corpuscle b/w
afferent & efferent arterioles & where distal tubule loops up & makes contact w/ afferent
arteriole
- collection of cells consisting of juxtaglomerular cells, macula densa, mesangial cells
- located in walls of afferent arterioles
- monitor renal pressure & help to maintain normal GFR through release of renin
- when renal perfusion is decreased these cells are responsible for releasing renin to
help increase GFR
- end result of renin is relase of angiotensin II which constricts efferent arteriole thereby
increasing press to glomerulus
- macula densa is a grp of epithelial cells located in distal convoluted tubule that are in
close contact w/ afferent & efferent arterioles. They help to regulate GFR.
-mesangial cells are located in section b/w afferent & efferent arterioles & among
glomerular capillaries. fxn as macrophages & are able to contract to regulate bl flow of
glomerular capillaries
✔✔renal blood flow - ✔✔- 1000-1200 ml of bl per min
- 20% of plasma is filtered out of capillaries & enters bowmans capsule; filtrate then
enters proximal tubule at a rt of 125ml/min which is known as GFR
- 80% pf plasma is not filtered into bowmans capsule but instead flows out fo glomerular
space & into efferent arterioles; efferent arterioles divide into millions of capillaries that
surround tubules & are called peritubular capillaries; network in conjunction w/ ep cells
of tubules is resp for solute exchange & H20 regulation
- renal arteries branch of the aorta, go into kidneys & become afferent arteriole of
glomerulus & form glomerular arterioles
- network then forms efferent arteriole which then forms peritubular capillaries which
eventually connect w/ venous system & then w/ IVC
✔✔NSAIDs and Renal Function - ✔✔- block production of renal protective
prostaglandins & can cause kidney injury, Na retention & edema
✔✔Angiontensin II - ✔✔- constricts mainly efferent arterioles in glomeruli
- causes an increase in GFR & glomerular press
✔✔ACE inhibitors - ✔✔- block action of angiotensin II on efferent arterioles & have a
renal protective quality in DM b/c it decreased press w/in glomeruli
, ✔✔Regulation of renal blood flow - ✔✔- affect amnt of bl which flows to kidneys & rt of
filtration
- decrease in art bl press or a decrease in EABV causes a decrease in renal perfusion
- decrease in renal perfusion causes filling pressure of glomerular arterioles to decrease
which in turn decreases GFR which l/d a decrease in fluid & Na in distal tubule
- decrease is sensed by JGA which then sends signals to afferent arterioles to relax
which increases flow of bl to glomeruli & JGA releases more renin which converts
plasma protein angiotensinogen to angiotensin I which then passes through lungs &
stim release of angiotensin II which stim vasoconstriction of efferent arterioles to help
increase glomerular back press & increases GFR
- angiotensin II also is resp for stim release of aldosterone which controls Na regulation
& signals collecting ducts in nephron to reabsorb Na. increased Na load l/d increase in
H2O retention & ult an increase in bl vol, BP, & GFR
✔✔Infants & renal system - ✔✔- urinary system dev during 3rd wk gestation
- glomeruli dev in stages & devmnt cont through ninth mo of gest
- kidneys ascend to sacral area around 6 wks gest, 3rd lumbar area by 3rd mo of gest &
to first lumbar area @ 9 mo
- @ birth kidneys occupy a lrg portion of post abd wall & ureters are shorter than an
adult
- all nephrons are present @ birth & # never increases
- urine form & excretion begin by 3rd mo of gest & contributes to amniotic fluid
- imm after birth renal bl flow & GFR increase d/t a decrease in vas resistance & need to
fxn now that placenta is detached
- renal vas resistance is high in newborns & infants b/c of increases levels of renin
- GFR reaches adult levels by 2
- infants have more dilute urine up to age 6mo
-kidneys are less resp to ADH
- urea excretion is low d/t high anabolic state & use of protein for growth
- tubular system is immature in infants & this r/s in a decreased ability to excrete K,
reabsorb bicarb or buffer hydrogen w/ ammonia
✔✔Aging and Renal Function - ✔✔-hypertrophy
- renal bl flow & GFR decrease
- number and size of nephrons decrease
- tubular atrophy
- glomerular cappillaries become sclerotic
- reduces ability to excrete urine
- specific gravity is lower
- glucose, bicarb, & Na are not efficiently reabsorbed
- hyperK is more common
- drugs are not cleared as easily
- inability to activate Vit D so Ca absorption is impaired
- freq, urgency, nocturia
✔✔nephrolithiasis - ✔✔- kidney stones
