Ch26 Urinary System
At a volume of __________ mL, there may be sufficient pressure in the bladder to force the opening of the internal urinary sphincter and, consequently, the external urinary sphincter.
500
The average pH for normal urine is about __________.
6.0 --slightly acidic
Introduction of plasma proteins into blood plasma is a fx of the urinary system (T/F)
False
The urethra carries urine from the kidneys to the bladder. (T/F)
False --the ureters carry urine from the kidneys to the bladder.
In which of the basic processes involved in urine formation does blood pressure force water and solutes across the wall of the glomerular capillaries?
Filtration
The __________ is the amount of filtrate produced in the kidneys each minute.
GFR -remember that this has to be maintained by adequate blood pressure in the kidneys.
Which portion of the nephron contains cuboidal cells covered with microvilli?
PCT
In which part of the nephron does aldosterone control the reabsorption of sodium ions?
distal convoluted tubule and collecting duct
ADH stimulates the reabsorption of water in ________ and in the _______.
distal convoluted tubule and the collecting system.
Describe how incontinence may develop in an elderly person:
due to decreased muscle tone of the sphincter controlling micturition/ disorders of the CNS affecting the ability to control urination.
Dilation of the afferent arteriole and glomerular capillaries and constriction of the efferent arteriole when blood flow and glomerular pressure decline cause __________.
elevation of glomerular blood pressure to normal levels
The ability to control the micturition reflex depends on your ability to control which muscle?
external urethral sphincter
Which mechanism is important in the reabsorption of glucose and amino acids when their concentrations in the filtrate are relatively high?
facilitated transport
Sympathetic innervation of the afferent arterioles causes ________ in GFR and _______ of filtrate production.
a decrease; slowing --remember this decreases urine formation.
Active secretion occurs primarily in the collecting duct. (T/F)
false
Regulating body temperature is one of the functions of the urinary system
false
Sodium and chloride are pumped out of the thin descending limb of the nephron loop. (T/F)
false
The digestive system is not used to excrete wastes from the body. (T/F)
false
The integumentary system is not used to excrete wastes from the body. (T/F)
false
With age comes increased sensitivity to ADH. (T/F)
false
bicarbonate is reabsorbed in the nephron loop. (T/F)
false
Urine, creatinine, glucose, and sodium are all waste products normally found in urine. (T/F)
false --glucose is not normal
The juxtaglomerular complex is the site of the release of aldosterone and ADH. (T/F)
false --the juxtaglomerular complex is the site of the release of renin and erythropoietin.
The kidneys are located posterior to the spleen, stomach, and liver; surrounded by a fibrous capsule of renal fascia; and are in front of the parietal peritoneum. (T/F)
false --they are behind the parietal peritoneum
Aldosterone stimulates ion pumps along the distal convoluted tubule (DCT), the collecting tubule, and the collecting duct, causing __________.
a reduction in the number of sodium ions lost in the urine --remember aldosterone helps the body hold onto water
Cortical radiate arteries branch to form __________, which enter __________.
afferent arterioles; glomeruli --remember that these arteries feed into smaller high-pressure vessels that lead into the filtration area.
Autoregulation controls the glomerular filtration rate (GFR) by dilation of the glomerular capillaries, constriction of the efferent arteriole, and dilation of the afferent arteriole. (T/F)
all true
What occurs when the plasma concentration of a substance exceeds it's tubular maximum?
aminoaciduria
The pressure that represents the resistance to flow along the nephron and conducting system is the __________.
capsular hydrostatic pressure (CHP) --this is acting in opposition to the flow of filtrate.
What are the opposing forces of the filtration pressure at the glomerulus?
capsular hydrostatic pressure and blood osmotic pressure --remember these are driving water back into the capillaries.
Juxtaglomerular nephrons produce __________ urine.
concentrated
The collecting system transports fluid to the renal pelvis and adjusts the _____ and _____ of urine.
concentration and composition --remember that this is the area where final modifications are made before excretion.
The thick segments in the nephron loop __________.
contain transport mechanisms that pump materials out of the filtrate.
In which region of the kidney would you find the renal corpuscles?
cortex
To which vessels does blood flow immediately after it passes through the arcuate arteries?
cortical radiate arteries
What is the term for the type of transport where two substrates cross the membrane while bound to a carrier protein, with at least one following its concentration gradient?
cotransport
Found in normal urine, __________ is an organic waste produced from the breakdown of CP in skeletal muscles.
creatinine
Inadequate ADH secretion results in the inability to reclaim the water entering the filtrate, causing __________.
dehydration
What is the triple-layered muscle responsible for urinary bladder contractions?
detrusor --remember this is composed of inner and outer layers of longitudinal smooth muscle.
Which of the disorder describes the production of very dilute urine as a result of a lack of ADH production?
diabetes insipidus --remember that insulin plays no part in this disease.
Which portion of the renal segment is under ADH and aldosterone stimulation?
distal convoluted tubule
What is the primary site for secretion of potassium and hydrogen ions into the filtrate?
distal convoluted tubule --remember this is downstream from the loop of Henle.
The filtration process within the renal corpuscle involves passage across the filtration membrane, which consists of _____, _____, and _____. What type of epithelium is here?
fenestrated capillary endothelium, dense layer, and filtration slits --remember this involves two types of epithelium
hat effect would low sodium concentration of filtration have on the pH of tubular fluid?
fewer hydrogen ions could be secreted by the counter transport mechanism involving these 2 ions. As a result the pH of the tubular fluid would rise.
The layer of collagen fibers that covers the outer surface of each kidney
fibrous capsule --remember that this is composed of a very abundant connective tissue protein.
The renal corpuscle consists of the ______ and the _______.
glomerulus and glomerular capsule. --Remember that this includes the capillaries and the surrounding compartment.
What results from the effect of aldosterone along the DCT, the collecting tubule, and the collecting duct?
increased conservation of sodium ions and water --remember that aldosterone will help the body increase blood pressure.
The collecting system in the kidney is responsible for __________.
making final adjustments to the sodium ion concentration and volume of urine --remember this involves fine-tuning the concentration of a cation in the ECF.
The inner layer of the kidney is the __________.
medulla
After passage through the nephron loop, the filtrate is (more/less) concentrated.
more concentrated --Remember that osmotic pressure increases.
When antidiuretic hormone levels rise, the distal convoluted tubule becomes __________.
more permeable to water; water reabsorption increases --remember that ADH helps prevent water loss.
Because of the small diameter of the glomerular capillaries, the blood pressure in the efferent arteriole is __________ that of the pressure in the afferent arteriole.
much higher than --remember that resistance increases inside a blood vessel the smaller the lumen is.
A histological examination of the nephron would reveal simple squamous tissue in the________ _______.
nephron loop
water, chloride, and sodium is reabsorbed in the ______ ________.
nephron loop
In which area of the nephron would counter-current multiplication occur?
nephron loop also known as the "loop of Henle."
What is the primary site in the nephron where the loss of water, sodium, and potassium ions is regulated?
nephron loop and collecting duct
Urine production begins in the __________.
nephrons
The difference between the net hydrostatic pressure and the net colloid osmotic pressure is the __________.
net filtration pressure
Countercurrent refers to the exchange occurring b/w fluids moving in _____ directions.
opposite
The fluid in the ascending limb of the nephron loop moves (same/different) direction of the fluid in the descending limb.
opposite
During the micturition reflex, increased afferent fiber activity in the pelvic nerves facilitates __________.
parasympathetic motor neurons in the sacral spinal cord
Blood supply to the proximal and distal convoluted tubules of the nephron is provided by the __________.
peritubular capillaries
The renal papilla __________. (location)
projects into the renal sinus
In a nephron, the long tubular passageway through which the filtrate passes includes the __________.
proximal and distal convoluted tubules and the nephron loop
In which area of the nephron are most nutrients reabsorbed?
proximal convoluted tubule
Sixty to 70 % of the water is reabsorbed in the __________.
proximal convoluted tubule
What is the primary site of nutrient reabsorption in the nephron?
proximal convoluted tubule --just outside the renal corpuscle.
Which portion of the nephron reabsorbs most of the important nutrients, such as glucose and amino acids as well as any plasma proteins?
proximal convoluted tubule (PCT) --remember that this region is just outside the glomerulus.
Aldosterone __________ in the proximal convoluted tubule.
regulates potassium and sodium exchange --remember that by regulating these electrolytes, fluid retention is also regulated.
In which region of the kidney would you find the renal corpuscles?
renal column
The filtration of plasma that generates approximately 80 liters/day of filtrate occurs in the __________.
renal corpuscle --remember this contains the glomerulus.
What is the dense fibrous layer that anchors the kidney to surrounding structures?
renal fascia
In what part of the kidney are the renal pyramids located?
renal medulla
The region of the kidney containing the renal pyramids, renal columns, and interlobar arteries is called the __________.
renal medulla
What is the expanded, funnel-shaped structure in the kidney leading to the ureter?
renal pelvis
The plasma concentration at which a specific compound will begin appearing in the urine is the _____ _____.
renal threshold --remember that this is above 100mg /dl for glucose.
What effect would high amounts of aldosterone have on the potassium concentration in urine?
since aldosterone promotes Na retention and K secretion by the kidneys, this would increase potassium concentration.
Hydrogen ion secretion is associated with the reabsorption of __________.
sodium --remember this happens through the action of a pump.
The high osmotic concentrations found in the kidney medulla are primarily caused by the presence of __________.
sodium ions, chloride ions, and urea
What transports fluid to the renal pelvis and adjusts the concentration and composition of urine
the collecting system
Net filtration pressure can be measured as __________.
the difference between the net hydrostatic pressure and the blood colloid osmotic pressure --remember that this is the resulting balance between the pressure against the walls of a blood vessel and the attractive force back into the blood vessel
The renal corpuscle consists of ________ and _______. What occurs here?
the glomerular capsule and the glomerulus --remember this is where filtration occurs.
Obstruction of ureter by a kidney stone would interfere with the flow of urine b/w which 2 points?
the renal pelvis and the urinary bladder
The capillaries surrounding the nephron loop are called __________.
the vasa recta --remember that these work with the nephron loop to maintain fluid homeostasis.
Why don't plasma proteins pass into the capsular space under normal circumstances?
too big
The ureters are lined by what kind of epithelium, which allows them to be stretched when undergoing peristalsis and moving urine?
transitional --remember this is the only epithelial cell that changes shape.
The mucosa of the urinary bladder consists of __________.
transitional epithelium
The openings of the urethra and the two ureters mark an area on the internal surface of the urinary bladder called the __________.
trigone
The area in the urinary bladder that is bounded by the openings of the ureters and the entrance to the urethra is the __________.
trigone Remember that this has a prefix that means "three."
Angiotensin II is a potent hormone that causes constriction of the efferent arteriole at the nephron. (T/F)
true
Angiotensin II is a potent hormone that stimulates secretion of aldosterone by the adrenal cortex and epinephrine by the adrenal medulla. (T/F)
true
Angiotensin II is a potent hormone that triggers the release of ADH in the CNS. (T/F)
true
Filtration occurs exlusively in the renal corpuscle, across the glomerular walls. (T/F)
true
Kidney stones, or calculi, can be formed by deposits of uric acid, calcium, and magnesium salts. (T/F)
true
Nutrient reabsorption occurs primarily at eh proximal convoluted tubule. (T/F)
true
Sympathetic innervation into the kidney is responsible for direct stimulation of water and sodium ion reabsorption. (T/F)
true
Sympathetic innervation into the kidney is responsible for regulation of glomerular blood flow and pressure. (T/F)
true
Sympathetic innervation into the kidney is responsible for stimulation of renin release. (T/F)
true
The lymphatic system is not used to excrete wastes from the body. (T/F)
true
The nephron loop reabsorbs roughly half the water and 2/3 the Na and Cl ions in the tubular fluid. (T/F)
true
The nephron loop regulates the amount of water lost in the urine. (T/F)
true
Release of renin leads to an increase in glomerular pressure. (T/F)
true --glomerular pressure increases when the efferent arteriole constricts due to the release of renin.
An immune response that produces large amounts of antibodies can lead to glomerulonephritis. (T/F)
true --while it is not the site of infection, the production of high numbers of antibodies is sufficient to clog the filtration mechanism in the nephron.
Osmosis, diffusion, and carrier-mediated transport are in involved in reabsorption and secretion at the kidneys. (T/F)
truet
Which organic wastes is generated from the catabolism of amino acids?
urea
What is the urinary structure that carries urine from the kidney to the urinary bladder?
ureter
Contraction of the muscular bladder forces the urine out of the body through the __________.
urethra --remember this is the last portion of the urinary tract.
The loss of muscle tone in the urinary sphincter muscles causes ___.
urinary incontinence --remember this is involves loss of voluntary control.
What is micturition?
urination
The __________ maintains the concentration gradient of the medulla by removing the solutes and water reabsorbed at the nephron loop.
vasa recta --remember that this is a capillary network that is closely associated with the tubular system.
How would the lack of juxtamedullary nephrons affect the volume and osmotic concentration of urine?
w/o JGC nephrons, a large osmotic gradient could not exist in the medulla, and the kidneys would be unable to form concentrated urine.
Why does a decrease in the amount of sodium in the distal convoluted tubule lead to an increase in BP?
when the amount of sodium in tubular fluid passing thru the distal convoluted tubule decreases, the cells of the macula densa are stimulated to release renin. The resulting activation of angiotensin2 increases BP.
Name 3 substances secreted by the distal convoluted tubule (DCT).
-ammonium ions, -hydrogen ions, -potassium ions
Name 3 examples of carrier-mediated transport.
-cotransport -facilitated diffusion -active transport
List 4 age related changes in the urinary sytem?
-decrease in functioning nephrons -decrease in GFR -decrease in sensitivity to ADH -problems w/ micturition reflex
Identify the role the urinary system plays for all other body systems?
-excretes wastes collected from blood -maintains normal body fluid pH and ion composition
The 3 major fx of the urinary system are:
-excretion: removal of organic waste from body fluids -elimination: discharge of waste products into the environment -homeostatic regulation of volume and solute concentration of blood (regulation of BP)
What are the three concentric layers of connective tissue that protect and anchor the kidneys?
-fibrous capsule, -perinephric fat capsule, -renal fascia
Identify the 3 distinct processes that form urine in the kidney
-filtration -reabsorption -secretion
List the factors that influence the rate of filtrate formation.
-filtration pressure across glomerular capillaries -interactions among autoregulation, hormonal regulation, and autonomic regulation
What nephron structures are involved in filtration?
-glomerular capillaries, -dense layer, -filtration slits of the podocytes.
List the factors that influence net filtration pressure:
-net hydrostatic pressure -blood colloid osmotic pressure
Identify the organs of the urinary system.
-paired kidneys -paired ureters -bladder -urethra
Name 3 things that the segments of the nephron distal to the renal corpuscle are responsible for.
-reabsorption of useful organic substrates, -reabsorption of over 90% of water from the tubule -secretion of waste materials
hich portions of a nephron are in the renal cortex?
-renal corpuscle -proximal portions of nephron loop -collecting duct
Name the body systems that make the excretory system:
-urinary -integumentary -respiratory -digestive system
The sympathetic division of the nervous system has which of the following effects on the kidney?
It causes a decrease in the GFR because of the constriction of the afferent arteriole. Remember that this is a result of the stress response.
How would a decrease in BP affect the GFR?
It would decrease the blood hydrostatic pressure w/in the glomerulus
Damage to which part of the nephron would interfere with the normal control of BP?
JGC/Juxtaglomerular complex of a nephron would interfere with the hormonal control of BP.
Elimination of waste into the environment is a fx of the urinary system (T/F)
True
Homeostatic regulation of the volume and solute concentration of blood plasma is a fx of the urinary system (T/F)
True
Removal of organic waste products from body fluids is a fx of the urinary system (T/F)
True
What is the initial factor that determines whether urine will be produced?
filtration --remember this is dependent on having sufficient blood pressure.
In countercurrent multiplication, the countercurrent refers to the fact that an exchange occurs between __________.
fluids moving in opposite directions
Define nepholithiasis
formation of calculi/kidney stones
The thin segments in the nephron loop are __________.
freely permeable to water and relatively impermeable to ions and other solutes --remember water passes through this region easily.
The amount of filtrate the kidneys produce each minute is the __________.
glomerular filtration rate
What is the term for the blood pressure in the capillaries of the renal corpuscle?
glomerular hydrostatic pressure
What is the outward pressure forcing water and solute molecules across the glomerulus wall?
glomerular hydrostatic pressure --remember this is driving the formation of filtrate.
When plasma glucose concentrations are higher than the renal threshold, glucose concentrations in the filtrate exceed the transport maximum (Tm), and __________.
glucose appears in the urine --remember this condition is seen in diabetics.
Which part of the kidney is the point of entry of the renal artery and renal nerves and has a prominent indentation.
hilum
During periods of strenuous exercise, sympathetic activation causes the blood flow to __________ to the skin and skeletal muscles and _______ to the kidneys.
increase; decrease --remember this will decrease urine formation.
What is the result of the countercurrent multiplication mechanism?
increased solute concentration in the descending limb of the nephron loop --remember that water escapes from the first part of the nephron loop.
To regulate pH, all of the following are secreted into the fluid in the collecting system EXCEPT __________.
iron --remember this is part of hemoglobin.
What effect would a high protein diet have on the composition of urine?
it would lead to increased production and concentration of urea due to the metabolism of a.a. from the breakdown of proteins.
Which of the following systems is NOT used to excrete wastes from the body?
lymphatic system --remember this is part of the immune system.
