What is the sum of all filtration rates of all functioning nephrons known as?
glomerular filtration rate
What does the leaky barrier of the filtration membrane allow and prevent from passing through?
allows water and certain solutes while preventing plasma proteins, blood cells from getting into capsular space
what are the cells of the bowman’s capsule that wrap around the glomerular capillaries?
podocytes
what are the 3 layers of the filtration membrane starting with the innermost?
fenestrations of endothelial cells, basement membrane/basal lamina, and slit membranes between pedicels
Which layer of the filtration membrane prevents blood cells from passing, but allows all other components of blood plasma through?
fenestrations of endothelial cells
Which layer of the filtration membrane prevents large proteins from passing through?
basal lamina
Which cells regulate the surface area available for filtration?
mesangial cells
Why is the filtration pressure higher in glomeruli than in any other capillaries in the body?
larger surface area, larger fenestrations, and efferent arteriole has a small diameter than afferent
What is the glomerular blood hydrostatic pressure?
pressure in glomerulus pushing outward into capsular space
How is GBHP (Glomerular blood hydrostatic pressure) different from CHP (Capsular hydrostatic pressure)?
CHP is opposite of GBHP, pressure that pushes inward on the visceral glomerular membrane
What filtration pressure is due to proteins in blood plasma and pulls solutes into the glomerulus?
BCOP (Blood colloidal osmotic pressure)
What is the formula of NFP and what does it do?
NFP=BHFP-CHP-BCOP;
Promotes filtration
NFP can still cause filtration if it is negative and lead to urine production. T or F?
F
Which pressure change leads to nephrolithiasis?
CHP increases pushing back flow into the glomerulus
What condition occurs when NFP is no longer supporting filtration?
hydronephrosis
What is the glomerular filtration rate and is it higher in males or females?
this is the amount of blood filtered through the kidney’s glomeruli into the capsular space per unit time. it is higher in males (90 - 140 mL/min)
What happens when GFR is too slow?
All filtrates may be reabsorbed and waste may not be excreted efficiently
A decreasing GFR means what to your doctor?
A progression of a chronic kidney disease
Which formula is used for estimating GFR?
Cockcroft-Gault formula
Which factors affect the calculation of GFR?
Age, Race, Weight, and Gender (GRAW)
Why is creatinine used in the calculation of GFR?
Because it is not reabsorbed after filtration and serum level should be at or near urine level
What happens to serum creatinine level when urine level is low?
It increases
Creatinine is a result of what process?
normal breakdown of muscle
The pressures that affect net filtration pressure also affect GFR. T or F?
T
GBHP is inversely related to GFR. T or F?
F
What effect does dilation of the afferent arteriole have on GBHP and GFR?
increases both
What effect does the dilation of the efferent arteriole have on the GBHP and GFR?
decreases both
what effect does the constriction of the afferent and efferent arteriole have on its resistance?
increases resistance
What are the mechanisms that regulate GFR?
renal autoregulation, neural regulation, and hormonal regulation
If the renal (kidney) autoregulation occurs due to innate actions, how does neural regulation of GFR occur?
sympathetic nervous system input
What are the hormones of the hormonal regulation of GFR?
Angiotensin II and Atrial natriuretic peptipte (ANP)
How does the kidney maintain a near constant GFR during renal autoregulation?
variable changes in resistance at afferent arteriole
Which renal autoregulation mechanism allows the transient (short) increase in GFR?
myogenic mechanism
How is the nephron integrity preserved with sudden increased blood pressure?
an initial reduction of GFR due to smooth muscle contraction of afferent arteriole
in the myogenic mechanism, an immediate increase in BP causes ___ which can cause ___?
myogenic vasoconstriction; compensatory vasodilation
What is the sole purpose of the juxtaglomerular apparatus (JGA)?
affect systemic blood pressure through autoregulation of tubuloglomerular feedback
What are the cells of juxtaglomerular apparatus (JGA)?
juxtaglomerular cells, macula densa cells, and lacis cells
What is another name for lacis cells?
extraglomerular mesangial cells
Which JGA cells are found in the walls of afferent arteriole?
juxtaglomerular cells
Which JGA cells are found in between afferent arteriole, efferent arteriole, and DCT?
lacis cells
which cells are found in the walls of the late thick ascending limb of LOH?
macula densa cells
juxtaglomerular cells are modified smooth muscle cells. T or F?
T
What are the 2 functions of the juxtaglomerular cells?
detect low blood pressure by lack of wall stretch and secrete renin to cause an increase in blood pressure
What are the 2 functions of the macula densa (specialized) cells?
detect increase in NaCL in filtrate; release locally acting ATP & adenosine causing contraction of afferent arteriole and reduction in GFR
Which JGA cell contract or relax to make small regulatory changes in response to signal from other JGA cells?
exraglomerular mesangial cells (lacis cells)
When the blood pressure and extracellular fluid volume is normal, the neural and hormonal regulation play a key role in maintaining constant GFR. T or F?
F
Blood vessels of the kidney are supplied by sympathetic nervous system fibers only. T or F?
T
The increase in sympathetic stimulation of the kidney causes ___ of the afferent arteriole.
vasoconstriction
The decrease of GFR helps to protect the ____ from rapid rise in pressure until autoregulatory compensation.
nephron
Which arteriole constricts first when GFR hormone, angiotensin II is activated?
efferent
The increase in the level of angiotensin II in the glomerular causes ____ of afferent arterioles which reduces ____?
vasoconstriction; GFR
The secretion of ANP by the atria and BNP by the brain is caused by a ____ in blood volume.
increase
How does ANP and BNP affect the afferent and efferent arteriole?
It causes dilatation of afferent and constriction of efferent
Increased secretion of ANP/BNP decreases GFR. T or F?
F
Which hormone conteracts the vasoconstricting effect of angiotensin II when BP is down?
prostaglandins
Which GFR hormonal regulator prevents renal ishemia?
prostaglandins
Which GFR hormonal regulator causes vasodilation of afferent and efferent arterioles counteracting the effect of angiotensin II?
Nitric oxide
Which GFR hormonal regulators are endothelial cell derived?
Nitric oxide and endothelin
Which GFR hormonal regulator is stimulated by angiotensin II and epinephrine to cause vasoconstriction of both afferent and efferent arterioles?
endothelin
Which vasodilator stimulates the release of NO and prostaglandins?
bradykinan
Which GFR hormonal regulator produced within kidneys causes vasoconstriction at afferent arteriole?
Adenosine
What is the function of angiotensin converting enzyme (ACE)?
converts angiotensin I to angiotensin II
Where is angiotensin converting enzyme located?
surface of endothelial cells lining afferent arteriole and glomerular capillaries
The RAAS is activated in response to ___ blood pressure.
low
RAAS is activated by the stimulation of ___ receptors found in juxtaglomerular cells.
beta 2 adrenergic
What change in luminal sodium chloride activates RAAS?
decrease in luminal NaCl
GFR is directly proportional to sodium chloride concentration. T or F?
T
Which hormones are released when RAAS is activated?
renin and angiotensinogen
If juxtaglomerular cells secrete renin, which cells secrete angiotensinogen?
hepatocytes (liver cells)
How is angiotensin 1 made after RAAS activation?
angiotensinogen reacts with renin to cleave off a 10-amino acid peptide
What happens to angiotensin-1 when it gets to the lung and kidney?
It is converted to angiotensin II by endothelial ACE
Angiontensin_II decreases ___ by causing ___ vasoconstriction of afferent arteriole and ___ vasoconstriction of efferent arteriole
GFR; major; minor
Angiotensin-II enhances __, __, & __ reabsorption in the PCT
water, sodium and chlorine ions
Angiotensin-II stimulates the adrenal cortex to release an hormone which stimulates principal cells in collecting ducts to reabsorb more sodium and chlorine ions and secrete more potassium. what is the hormone?
aldosterone
What effect does the increased reabsorption of water, sodium and chlorine ion have on blood volume and pressure?
increases
Which hormone that causes more water reabsorbtion does angiotensin-II release in the posterior pituitary gland?
ADH
Which condition is an ACE inhibitor used to treat?
hypertension
How does ACE inhibition help reduce blood pressure?
ensures that angiotensin-II does not stimulate aldosterone and ADH
What are the differences btw active and passive transport?
passive does not ATP while active requires ATP to occur; passive is from high conc. to low while active is vice versa
Glomerular filtration is an example of ___ movement
passive
Sodium/potassium pumps is an example of ___ movement
active
In addition to the efforts of the renal tubule and ducts, ____ cells makes the largest contribution to reabsorption.
proximal convoluted tubule (PCT)
Which distal cells “fine tune” the reabsorption process?
LCD; loop of henle, collecting duct and distal convoluted tubule (DCT)
By what process are small proteins and peptides reabsorbed after passing through glomerular filter?
pinocytosis
The apical membrane is the ___ side of the cell and the basolateral membrane is the ___ side of the cell.
apical; interstitial
What is the difference between tubular paracellular and transcellular reabsoption?
paracellular is btw tubule cells and transcellular is within the same tubule cell
Which tubular reabsorption method accounts for 50% of reabsorption?
paracellular reabsorption
obligatory water reabsorption is the reabsorption of water by ___ reabsorption via ___
solute; osmosis
90% of reabsorption occurs in which part of the kidney?
PCT and descending limb of the loop of henle
10% of water reabsorption is occurs by ___ water reabsorption.
facultative
Where does facultative water reabsorption occur?
late DCT and collecting ducts
Which hormone regulates facultative water reabsorption?
ADH
What leads to glucosuria?
a high concentration of plasma glucose which cannot be reabsorbed quickly enough; instead lost through urine
___ is the transfer of materials from the capillaries, interstitial spaces, and tubule cells into the filtrate.
tubular secretion
Can anabolic steroids, hCG and hGH be detected by urinalysis test?
Yes
Erythropoietin and amphetamines cannot be detected by urinalysis. T or F?
F
A ___ layer of ___ cells forms the entire wall of the glomerular capsule, renal tubule and ducts
single; epithelial
What type of epithelial cells are found on PCT?
simple cuboidal with prominent microvilli
What is the function of microvilli on the epithelilal cells of PCT?
increase surface area for reabsorption and secretion
What type of epithelial cells are found on LOH (thin descending and ascending limb portions)?
simple squamous
All parts of the renal tubule is made up of simple cuboidal epithelial cells except ___?
LOH (thin ascending and descending limb portions)?
which parts of the renal tubule contain principal cells and intercalated cells?
DCT and collecting duct
tubular secretion of ___ ions helps to regulate pH
hydrogen
Principal cells have receptors for ___ and ___
ADH; aldosterone
Intercalated cells play a role in ___
blood pH
The constant movement of things across the membranes (tubule cell; interstitial fluid; capillary) leads to an ___ gradient and ___ gradient
osmotic and electric
___ is a nitrogenous waste created from protein catabolism
ammonia
___ is more toxic substance than ___ that must be deadly when left to accumulate instead of excreted.
Ammonia and urea
Ammonia is converted into ___ in the ___ and excreted as ___ by the ___
urea; liver; urine; kidney
Which disease is caused by urea in the blood instead of excretion through the kidney (kidney failure)?
uremia
Checking the ___ levels and ___ levels can give a provider a good picture of a patient’s uremic state
blood urea nitrogen; creatinine
Urea in the blood reverting back to ammonia will lead to a ___
septic state
In what form is bicard reabsorbed in the PCT?
carbonic acid after reaction with hydrogen ion
bicard serves as an important ___ in the body
buffer
In what form does bicard diffuse into the tubule cell?
carbonic acid dissociates into carbon dioxide and water before entering the cell
for every ___ ion secreted into tubular lumen, one ___ and one ___ ion are absorbed
hydrogen;bicarb; sodium
largest amount of solute and water reabsorption from filtered fluids occurs in the ___
PCT
100% of glucose, amino acid, and vitamins are reabsorbed in the PCT. T or F
T
What substances co-transported during sodium ions active transport from tubule into intersitial fluid?
amino acid and glucose
Which ions are passively introduced into interstitial fluid to balance sodium ions?
chloride ions
movement of sodium and calcium into interstitial fluid causes an osmotic imbalance resolved by movement of ___ from filtrate into interstitum
water
The cell lining of PCT and the ___ LOH possess ___ channels which aids water permeability.
descending; aquaporin-1
the osmosis of water will often bring pottasium and calcium ion in a process called?
solvent drag
PTH stimulates cells in the PCT to secrete ___ and ___
phosphate; cacitriol (vitamin D)
cacitriol (vitamin D) causes ___ to be absorbed from digestive system
calcium
PTH stimulates cell in the DCT to reabsorb ___
calcium
___ reabsorption occurs at the descending limb of LOH and ___ reabsorption occurs at the ascending limb of LOH
water;solute
hyperosmosis is caused by more ___ and less ___
solute;water
no water reabsorption occurs at the thin and think portion of the ascending limb LOH. T or F?
T
thin portion of the ascending LOH is ___ permeable to solutes and the thick portion of the ascending LOH is ___ permeable to solutes.
passively;actively
macula densa cells are formed in the ___
think portion of the ascending LOH
the amount of solute/water reabsorption is dependent on the feedback from ___ and ___
hormones; osmoreceptors
DCT and PCT reabsorb sodium ion through ___
active transport
Although normally impermeable to water, ___ hormone causes principal cells of DCT and collecting ducts to become permeable to water by generating ___ channels
ADH; aquaporin-2
In the presence of ADH when more water is reabsorbed (creating an osmotic imbalance), urea is also reabsorbed at the ___ ducts migrates through interstitial fluid and gets secreted in the ___
distal collecting; descending limb of the LOH
aquaporin-2 functions in the presence of ___, while aquaporin-1 function ___ in the PCT/LOH
ADH; independently
hypekalemia causes ___ to be released
aldosterone
aldosterone causes principal cells to reabsorb ___ and secret ___
sodium (with water); potassium
type A of intercalated cells causes secretion of ___ and the reabsorption of ___ and ___
hydrogen ions; bicarb and potassium ions
type B of intercalated cells causes secretion of ___ and ___ and the reabsorption of ___
potassium ions and bicarb; hydrogen ions
ANP is stimulated by what change in blood pressure?
increased blood pressure
ANP inhibits ___, ___ and ___
sodium ion, water, and RAAS
The regulation of plasma osmolarity is the responsibility of ___, ___, and ___
LOH, DCT, and collecting ducts
descending limb of LOH ___ urine, ___ ascending limb of LOH ___ urine
concentrates; think;dilutes
the final dilution/concentration of urine controlled the presence/absence of ___ occurs at ___ and ___
ADH; DCT; collecting ducts
what is the volume of urine produced in a 24 hr period?
1-2 liters
what is the normal color of urine and what causes blood in urine?
yellow to amber; kidney stones
what is the turbidity of urine?
transparent at first; cloudy with time
what is the odor of urine?
mildly aromatic
what is the normal pH range and average of urine?
4.6 - 8.0; 6.0
protein increases the ___ of pH and vegetables increases ___ of pH
acidity; alkalinity
what is the usual specific gravity of urine?
1.001 - 1.035
the ____ the concentration of solutes, the higher the specific gravity
higher
normal urine contains protein. T or F?
F
what accounts for majority of urine?
water
solutes such as urea is from the breakdown of ___, uric acid is from the breakdown of ___, and urobilinogen is from the breakdown of ___
proteins; nucleic acid; hemoglobin
fatty acids, pigments, and enzymes are solutes found in urine. T or F?
T
What are the 2 blood tests that provide information on kidney function?
Blood Urea Nitrogen and plasma creatinine
creatinine is reabsorbed in the kidney. T or F?
F
When GFR ___, BUN increases?
reduces
renal clearance is the ___ that can be completely ___ of a substance per unit time
volume of plasma; cleared/excreted
___ is a great measure of GFR because it is easily filtered and excreted completely (100%) through urine
inulin plant polysaccharide
creatinine is a ___ estimate of GFR and the lab values needed to complete it are 24 hr ___ and ___
urine collection and plasma concentration
collecting ducts – ? –papillary ducts – ? – major calyces – ? – ureters – ? – urethra
papillary: minor calyces; renal pelvis; urinary bladder
urine is transported by ___ from the renal pelvis to urinary bladder
peristalsis
ureters are ___ walled, ___, and retroperitoneal
thick, narrow, retroperitoneal
ureter passes ___ into ___ aspect of bladder
obliquely; posterior/inferior
the physiologic valve of the ureter ___ the bladder ___ to close the “valve” avoiding backflow. This process is also known as ___
pulls; down; anti-reflux mechanism
What are the 3 layers of the ureter starting with the innermost?
mucosa (globlet cells), muscularis (inner longitudinal smooth muscle), and adventitia
the urinary bladder is ___ when empty and pear-shaped when ___
collapsed; pear-shaped
The urinary bladder is ___ of the rectum (males) and vagina (females)
anterior
The urinary bladder is ___ to pubic symphysis and ___ to uterus in females
posterior; inferior
What holds the urinary bladder in place?
peritoneal folds
what is the difference in the muscularis of the ureter and bladder?
the ureter version is made of smooth muscle while bladder version is made of detrusor muscle
What happens when the detrusor muscle of the muscularis layer of the bladder is relaxed and contracted?
bladder is filled during relaxation and contraction forces urine into the urethra
Comparing the ureter and bladder layers, what is the extra outer layer on the bladder and what does it cover?
serosa covers superior surface and visceral peritoneum
the smooth triangular area in the bladder floor is known as?
trigone
the bladder is ___ to the urethra
superior
the internal urethral sphincter is involuntary and made of ___ and the external urethral sphincter is ___ and made of skeletal muscle
smooth muscle; voluntary
the internal urethral sphincter is located ___ to the bladder and ___the prostrate in males
inferior; above
where is the external urethral sphincter located in males and females
below prostrate in males; at the opening of the external urethral orifice
__ 4-5x longer than female version, dual function (semen, urine), and consists of mucosa and muscularis layers
mare urethra
the longest region of the male urethra passing through the penis is the ___
spongy
___ is the shortest region of the male urethra forming the external urethral sphincter
membranous
___ contains smooth muscle that forms internal urethral sphincter (male urethra) and ducts that transport prostatic fluids and sperm
prostatic
spongy urethra (in males) contains ___ that delivers alkaline fluid to help neutralize acidity of urethra
bulbourethral (cowper’s gland)
female urethra is ___ to pubis symphysis
posterior
female urethra runs ___ from the bladder neck and and to the vaginal vestibule
inferior/anterior
what renal organ is btw the clitoris and vaginal orfice?
female urethra
mucosa layer of female urethra is ___ epithelium near bladder, ___ columnar in the middle, and ___ near external urethral orfice
transitional; pseudostratified; non-keratinized stratified
the involuntary contractions of detrusor muscle causing the ___ sphincter to open
internal urethral
what causes the voluntary contraction that prevents urination?
external urethral sphincter
micturition is the discharge of urine. T or F?
T
the increased incidence of calculi, renal inflamation, polyuria, nocturia, and dysuria is caused by ___ deterioration after ___
nephron; aging
the kidney is partially protected by the ___ ribs
11th and 12th
the kidney is located btw the ___ and ___ vertebrae in the ___ space
last thoracic and 3rd lumbar; retroperitoneal
the ___ border of the kidney faces the spinal column
cocave medial
what is the innermost layer of the kidney with smooth connective tissue?
renal capsule
What is the middle layer of the kidney and what type of tissue does it have?
adipose; fatty tissue
renal fascia is the ___ layer of the kidney with ___ connective tissue
outermost; dense
What part of the kidney contains all of the glomeruli and convoluted tubules of nephron?
cortex
the narrow apex of the pyramid is known as?
papilla
a unit of a medulla is known as the ___
pyramid
what part of the kidney contains the loops of henle and collecting ducts
medulla
minor calyx collect urine from ___ while major calyx collect urine from ___
papilla; minor calyx
spaces btw renal pyramids are known as
columns
a functional region of the kidney is known as a ___?
lobe (pyramid++cortex+1/2 each adjacent column)
where do the major calyces of the kidney drain into?
renal pelvis
the spaces in the kidney where blood vessels and nerve supply pass through are known as?
renal sinuses
___ is the indentation of the kidney where the ureter emerges with blood and lymphatic vessels
renal helium
What is the acronym for the blood supply to the kidney that starts with aorta and ends with inferior vena cavae?
ARSI/AI/AGE/PV/IAIRA
The blood supply starts from goes from the arteries, to arterioles, to glomerulus, capillaries, and veins. T or F?
T
The glomerulus allows filtration and reabsorption. T or F?
F (strictly filtration)
blood enters through the ___ to get filtered by the glomerulus and exits through ___ to proceed to the capillary system
corpuscle (2x)
The ___ capillary acts as a secondary filter which can reabsorb and secrete
peritubular
filtrate is first found in ___ from where it flows into the ___ then into the collecting ducts
bowman’s capsule (glomerular capsule); tubules
filtrate becomes urine after leaving the ___
collecting duct
a functional unit of the kidney is known as?
nephron
the 2 parts of the nephron are ___ where blood is filtered and ___ where filtered blood goes
renal corpuscle; renal tubule
Renal corpuscle is made of GG and renal tubule is made of PLD. What do the acronyms mean?
GG; glomerulus, glomerular capscule |
PLD; PCT, LOH, and DCT
which part of the renal tubule is connected to the renal corpuscle?
PCT
of the parts of the nephron, which one is only found in the renal medulla?
LOH
what are the 2 types of nephrons?
cortical and juxtamedullary nephron
Which type of nephron is the most common and found on the outer portion of the renal cortex?
cortical nephron
which type of nephron has long loops of henle and has peritubular capillaries that give rise to ___ recta?
juxtamedullary nephron; vasa
The anatomy of the ___ of the juxtamedullary nephrons that lends to very dilute or concentrated urine
long nephrons
the short and long nephron start and end in the ___
cortex
the component of the juxtamedullary nephron that is very important for maintaining constant osmotic gradient is known as?
vasa recta
___ arteriole brings blood into the corpuscle possessing wider and thicker walls for constriction and dilation
afferent
the smaller lumen size and thinner walls of the ___ arteriole aids in back-pressure sometimes needed for glomerular filtration
efferent