The Urinary System
Composed of simple squamous epithelium
A
Which of the hormones below is responsible for facultative water reabsorption? A) ADH B) thyroxine C) aldosterone D) atrial natriuretic peptide
A ADH
12) The renal corpuscle is made up of ________. A) Bowman's capsule and glomerulus B) the descending nephron loop C) the renal pyramid D) the renal papilla
A Bowman's capsule and glomerulus
The function of angiotensin II is to ________. A) constrict arterioles and increase blood pressure B) decrease the production of aldosterone C) decrease arterial blood pressure D) decrease water absorption
A Constrict arterioles and increase BP
Select the correct statement about urinary system development. A) Kidneys develop from urogenital ridges. B) The metanephric ducts will become the urethras. C) The pronephros (first tubule system) develops during the tenth week of gestation. D) The mesonephros will develop into the kidneys.
A Kidneys are for urogenital ridges
Which of the choices below is the salt level-monitoring part of the nephron? A) macula densa B) principal cell C) vasa recta D) nephron loop
A Macula densa
The functional and structural unit of the kidneys is the ________. A) nephron B) nephron loop C) glomerular capsule D) capsular space
A Nephron
The mechanism that establishes the medullary osmotic gradient depends most on the permeability properties of the ________. A) nephron loop B) glomerular filtration membrane C) collecting duct D) distal convoluted tubule
A Nephron loop
Select the correct statement about the nephrons. A) The parietal layer of the glomerular capsule is simple squamous epithelium. B) The glomerulus is correctly described as the proximal end of the proximal convoluted tubule. C) Podocytes are the branching epithelial cells that line the tubules of the nephron. D) Filtration slits are the pores that give fenestrated capillaries their name.
A Parietal layer is simple squamous epithelium
Which of the following is the correct sequence of kidney development from embryo to fetus? A) pronephros, mesonephros, metanephros B) mesonephros, pronephros, metanephros C) pronephros, metanephros, mesonephros D) mesonephros, metanephros, pronephros
A Pronephros, mesonephros, metanephros
Glomerulus
A Site of filtrate formation
Which of the following acts as the trigger for the initiation of micturition (voiding)? A) the stretching of the bladder wall B) motor neurons C) the pressure of the fluid in the bladder D) the sympathetic efferents
A Stretching
The urinary bladder is composed of ________ epithelium. A) transitional B) simple squamous C) stratified squamous D) pseudostratified columnar
A Transitional
What is the most direct function of the juxtaglomerular apparatus? A) help regulate blood pressure and the rate of blood filtration by the kidneys B) help regulate blood pressure and the rate of excretion by the kidneys C) help regulate urea absorption by the kidneys D) help regulate water and electrolyte excretion by the kidneys
A regulate BP and rate of blood filtration
Explain how an angiotensin converting enzyme inhibitor (ACE inhibitor) such as captopril would be effective as an antihypertensive.
Angiotensin II is a potent vasoconstrictor activating smooth muscle of arterioles throughout the body, causing mean arterial blood pressure to rise. ACE inhibitors reduce blood pressure by interrupting the renin-angiotensin-aldosterone system.
ADH activated water channels called ________ are essential for water reabsorption in the collecting duct.
Aquaporins
Which of the choices below are the most important hormone regulators of electrolyte reabsorption and secretion? A) angiotensin II and ADH B) angiotensin II and aldosterone C) angiotensin I and epinephrine D) angiotensin I and atrial natriuretic peptide
B Angiotensin II and aldosterone
The ________ artery lies on the boundary between the cortex and medulla of the kidney. A) lobar B) arcuate C) interlobar D) cortical radiate
B Arcuate
A disease caused by inadequate secretion of antidiuretic hormone (ADH) by the pituitary gland with symptoms of polyuria is ________. A) diabetes mellitus B) diabetes insipidus C) diabetic acidosis D) coma
B Diabetes Insipidus
The factor favoring filtrate formation at the glomerulus is the ________. A) colloid osmotic pressure of the blood B) glomerular hydrostatic pressure C) capsular hydrostatic pressure D) myogenic mechanism
B Glomerular hydrostatic pressure
An increase in the permeability of the cells of the collecting tubule to water is due to a(n) ________. A) decrease in the production of ADH B) increase in the production of ADH C) increase in the production of aldosterone D) decrease in the concentration of the blood plasma
B Increase in ADH
What would happen if the capsular hydrostatic pressure were increased above normal? A) Net filtration would increase above normal. B) Net filtration would decrease. C) Filtration would increase in proportion to the increase in capsular pressure. D) Capsular osmotic pressure would compensate so that filtration would not change.
B Net filtration would decrease
The mechanism of water reabsorption by the renal tubules is ________. A) active transport B) osmosis C) filtration D) cotransport with sodium ions
B Osmosis
Collecting duct
B Site that drains the distal convolute tubule
The fatty tissue surrounding the kidneys is important because it ________. A) ensures adequate energy for the adrenal glands to operate efficiently B) stabilizes the position of the kidneys by holding them in their normal position C) is necessary as a barrier between the adrenal glands and kidneys D) produces vitamin D and other chemicals needed by the kidney
B Stabilizes
Which of the following is not associated with the renal corpuscle? A) a podocyte B) a vasa recta C) a fenestrated capillary D) an efferent arteriole
B Vasa Recta
Which of the choices below is a function of the nephron loop? A) form a large volume of very concentrated urine or a small volume of very dilute urine B) form a large volume of very dilute urine or a small volume of very concentrated urine C) absorb electrolytes actively and water by osmosis in the same segments D) absorb water and electrolytes into the tubular network
B Very large volume of very dilute urine/ small volume of concentrated urine
Excretion of dilute urine requires ________. A) relative permeability of the distal tubule to water B) impermeability of the collecting tubule to water C) transport of sodium and chloride ions out of the descending nephron loop D) the presence of ADH
B impermeability of collecting tubule to water
An important characteristic of urine is its specific gravity or density, which is ________. A) the same as water B) slightly higher than water C) much higher than water D) less than water
B slightly higher that water
Cells that are most affected by ADH
C
Collecting duct cells
C
If one says that the clearance value of glucose is zero, what does this mean? A) The glucose molecule is too large to be filtered out of the blood. B) Most of the glucose is filtered out of the blood and is not reabsorbed in the convoluted tubules. C) Normally all the glucose is reabsorbed. D) The clearance value of glucose is relatively high in a healthy adult.
C All glucose is reabsorbed
If the Tm for a particular amino acid is 120 mg/100 ml and the concentration of that amino acid in the blood is 230 mg/100 ml, the amino acid will ________. A) be actively secreted into the filtrate B) be completely reabsorbed by the tubule cells C) appear in the urine D) be completely reabsorbed by secondary active transport
C Appear in urine
Peritubular capillaries
C Blood supply that directly receives substances from tubular cells
The kidneys are stimulated to produce renin ________. A) when the peritubular capillaries are dilated B) when the pH of the urine decreases C) by a decrease in the blood pressure D) when the specific gravity of urine rises above 1.10
C By decrease in blood pressure
The glomerulus differs from other capillaries in the body in that it ________. A) has a basement membrane B) is impermeable to most substances C) is drained by an efferent arteriole D) has a blood pressure much lower than other organ systems
C Drained by efferent arteriole
Which of the choices below is not a glomerular filtration rate control method? A) renal autoregulation B) neural regulation C) electrolyte levels D) hormonal regulation
C Electrolyte levels
The chief force pushing water and solutes out of the blood across the filtration membrane is ________. A) the ionic electrochemical gradient B) protein-regulated diffusion C) glomerular hydrostatic pressure (glomerular blood pressure) D) the size of the pores in the basement membrane of the capillaries
C Glomerular blood pressure
Most electrolyte reabsorption by the renal tubules is ________. A) not limited by a transport maximum B) in the distal convoluted tubule C) hormonally controlled in distal tubule segments D) accomplished after the nephron loop is reached
C Hormonally controlled in distal tubule segments
Which of the following is not a part of the juxtaglomerular complex? A) granular cells B) macula densa C) podocyte cells D) mesangial cells
C Podocyte cells
The filtration membrane includes all except ________. A) glomerular endothelium B) podocytes C) renal fascia D) basement membrane
C Renal fascia
Select the correct statement about the ureters. A) Ureters contain sphincters at the entrance to the bladder to prevent the backflow of urine. B) The epithelium is stratified squamous like the skin, which allows a great deal of stretch. C) The ureters are capable of peristalsis like that of the gastrointestinal tract. D) The ureter is innervated by parasympathetic nerve endings only.
C Ureters use peristalsis
Which of the choices below is the least important role of tubular secretion? A) disposing of substances not already in the filtrate, such as certain drugs B) eliminating undesirable substances such as urea and uric acid that have been reabsorbed by passive processes C) ridding the body of bicarbonate ions D) ridding the body of excessive potassium ions
C ridding body of bicarbonate ions
Explain what is meant by the terms cotransport process and transport maximum.
Cotransport process refers to the active transport of one solute "uphill" (against a concentration gradient) coupled to the "downhill" (with a concentration gradient) movement of another during tubular reabsorption. Transport maximum reflects the number of carriers in the renal tubules available to "ferry" a particular substance.
Rachael has been complaining of frequent and burning urination. She also reported seeing some blood in her urine. Her physician suspects cystitis. What is cystitis, and how can it cause these symptoms?
Cystitis is caused by bacterial invasion of the bladder or by chemical or mechanical irritation. Burning on urination alone implies urethritis (inflammation of the urethra alone) but urinary frequency suggests the bladder itself is also involved, with the inflammation causing smooth muscle irritability lowering the stretch trigger point for micturition.
Almost NO water is absorbed in these cells
D
Place the following in correct sequence from the formation of a drop of urine to its elimination from the body. 1. major calyx 2. minor calyx 3. nephron 4. urethra 5. ureter 6. collecting duct A) 3, 1, 2, 6, 5, 4 B) 6, 3, 2, 1, 5, 4 C) 2, 1, 3, 6, 5, 4 D) 3, 6, 2, 1, 5, 4
D 3, 6, 2, 1, 5, 4
The macula densa cells respond to ________. A) aldosterone B) antidiuretic hormone C) changes in pressure in the tubule D) changes in solute content of the filtrate
D Changes in solute content of filtrate
Which of the following is not reabsorbed by the proximal convoluted tubule? A) Na+ B) K+ C) glucose D) creatinine
D Creatinine
Which of the choices below is not a function of the urinary system? A) helps maintain homeostasis by controlling the composition, volume, and pressure of blood B) regulates blood glucose levels and produces hormones C) maintains blood osmolarity D) eliminates solid, undigested wastes and excretes carbon dioxide, water, salts, and heat
D Eliminates solid wasted and excretes CO2, water, salts, and heat
Alcohol acts as a diuretic because it ________. A) is not reabsorbed by the tubule cells B) increases the rate of glomerular filtration C) increases secretion of ADH D) inhibits the release of ADH
D Inhibits release of ADH
Which of the following best describes kidney function in older adults (70 years or older)? A) Kidney function remains the same throughout life, regardless of age. B) Only about 3% of older adults have any loss of kidney function. C) Only obese and diabetic older adults have any kidney dysfunction. D) Kidney function decreases due to kidney atrophy.
D Kidney unction decreases due to kidney atrophy
Which of the following does not describe the justaglomerular complex? A) It regulates the rate of filtrate formation. B) It helps control systemic blood pressure. C) Its granular cells produce rennin. D) Its macula densa cells produce aldosterone.
D Macula dense cells produce aldosterone
Which of the following is the least important influence on reabsorption of a substance in the nephron? A) number of carriers. B) lipid solubility. C) molecule size relative to fenestrations. D) molecular complexity
D Molecular complexity
The fluid in the glomerular (Bowman's) capsule is similar to plasma except that it does not contain a significant amount of ________. A) glucose B) hormones C) electrolytes D) plasma protein
D Plasma protein
Which of the following is not true regarding tubular reabsorption? A) It occurs via transcellular or paracellular routes. B) It is a reclamation process. C) It involves hormonal signals in the collecting ducts. D) It is a purely passive transport process.
D Purely passive transport process
Reabsorption of high levels of glucose and amino acids in the filtrate is accomplished by ________. A) facilitated diffusion B) passive transport C) countertransport D) secondary active transport
D Secondary active transport
Which of the choices below is not a method by which the cells of the renal tubules can raise blood pH? A) by secreting hydrogen ions into the filtrate B) by reabsorbing filtered bicarbonate ions C) by producing new bicarbonate ions D) by secreting sodium ions
D Secrete sodium ions
Proximal convoluted tubule
D Site at which most of tubular reabsorption occurs
In the ascending limb of the nephron loop the ________. A) thin segment is freely permeable to water B) thick segment is permeable to water C) thin segment is not permeable to sodium and chloride D) thick segment moves ions out into interstitial spaces for reabsorption
D Thick segment to interstitial spaces
The descending limb of the nephron loop ________. A) is not permeable to water B) is freely permeable to sodium and urea C) pulls water by osmosis into the lumen of the tubule D) contains fluid that becomes more concentrated as it moves down into the medulla
D contains fluid that becomes more concentrated as It moves down into the medulla
Which cells of the kidney are chemoreceptors that respond to changes in solute content of the filtrate? A) juxtaglomerular cells B) mesangial cells C) macula densa cells D) podocytes
D podocytes
Cells most active in reabsorbing the filtrate
E
Cells that reabsorb virtually all the nutrients
E
Filtrate at the site of these cells is about the same osmolarity as blood plasma
E
proximal convoluted tubule cells
E
Humans can survive for a period of time without water thanks to the ability of the kidneys to produce concentrated urine. Briefly explain the factors that allow this to happen.
Facultative water reabsorption depends on the presence of antidiuretic hormone. In the presence of ADH, the pores of the collecting tubule increase in number and the filtrate loses water by osmosis as it passes through the medullary regions of increasing osmolarity. Consequently, water is conserved and urine becomes concentrated. The water that passes through these regions is reabsorbed by the body in order to prevent dehydration.
An excessive urine output is called anuria.
False
Angiotensin II is a substance made by the body to lower blood pressure during stress.
False
Blood pressure in the renal glomerulus is lower than in most parts of the body in order to conserve body water.
False
Both the male and female urethras serve the urinary and the reproductive systems.
False
Fetal kidneys have the primary responsibility of clearing wastes from the fetal blood.
False
Glomerular filtration is an ATP-driven process.
False
Having a kinked ureter is called renal ptosis.
False
If the GFR is too low, needed substances may pass so quickly through the renal tubules that they are not absorbed and instead are lost in the urine
False
The collecting duct is impermeable to water in the presence of ADH.
False
The macula densa cells are chemoreceptors that respond to changes in the urea content of the filtrate.
False
The myogenic mechanism reflects the tendency of vascular smooth muscle to stretch.
False
The path urine takes after it is formed until it leaves the body is the urethra, urinary bladder, and finally the ureter
False
The proximal convoluted tubule is the portion of the nephron that attaches to the collecting duct.
False
The trigone is so named because of the shape of the urinary bladder.
False
Urea is reabsorbed in the nephron loop.
False
Glomerular capillaries
Fenestrated vessels that allow passage of all plasma elements but no blood cells (E)
Explain how filtration works in the glomerular capillaries.
Glomerular capillaries are fenestrated, allowing large molecules to pass through. The substances must pass through the basement membrane, where they are further selected for size by the filtration slits of the podocytes.
List and describe three pressures operating at the filtration membrane, and explain how each influences net filtration pressure.
Glomerular hydrostatic pressure is the chief force pushing water and solutes across the filtration membrane. The higher the glomerular hydrostatic pressure, the more filtrate is pushed across the membrane. Colloid osmotic pressure of plasma proteins in the glomerular blood, and capsular hydrostatic pressure exerted by fluids in the glomerular capsule, drive fluids back into the glomerular capillaries. The net filtration pressure equals glomerular hydrostatic pressure minus the sum of colloid osmotic pressure of glomerular blood and capsular hydrostatic pressure
Afferent arterioles
High pressure vessel that forces fluid and solutes into the glomerular capsule (A)
Explain the role of aldosterone in sodium and water balance.
It targets the distal tubule and collecting duct and enhances sodium ion reabsorption so that very little leaves the body in urine. It also causes increased water reabsorption because, as sodium is reabsorbed, water follows it back into the blood.
Peritubular Capillaries
Low pressure, porous vessels that reabsorb solutes and water from the tubule cells (C)
Efferent arterioles
May form meandering vessels or bundles of long straight vessels (B)
The ________ mechanism is the general tendency of vascular smooth muscle to contract when stretched.
Myogenic
The need to get up in the middle of the night to urinate is called ________.
Nocturia
Sodium-linked water flow across a membrane not under hormonal control is called ________ water reabsorption.
Obligatory
Vasa recta
Play a role in urine concentration (D)
Ellen, a 47-year-old woman who has suffered kidney disease for several years, has been diagnosed with proteinuria. Her legs and feet are so swollen that she has difficulty walking. Her hands and her left arm are also swollen. What is proteinuria, and could this condition be playing a role in her swollen limbs?
Proteinuria is a condition in which the permeability of the glomerular capillaries is increased to such an extent that large amounts of plasma proteins pass into the glomerular filtrate and are excreted in the urine. If the condition is severe, the loss of plasma proteins may decrease osmotic pressure substantially. When this happens, fluid usually leaves the systemic blood vessels and enter the tissue space.
The presence of pus in the urine is a condition called ________.
Pyuria
A 58-year-old woman complains of loss of urine when coughing and sneezing, and during exercise. She has had three children. Describe the possible causes of urinary incontinence in this patient.
Stress incontinence is found usually in women with relaxed pelvic musculature deprived of estrogen. It may occur with a sudden increase in intra-abdominal pressure such as coughing or sneezing, which forces urine through the external sphincter. Aging, multiple pregnancies, and obesity are risk factors in increasing the relaxation and pressure.
Eleven-year-old Harry is complaining of a severe sore throat and gets to stay home from school. His pediatrician prescribes a course of broad-spectrum antibiotics, and Harry feels much better within a few days. However, some two weeks later, Harry has a dull, bilateral pain in his lower back and his urine is a smoky brown color. On the basis of Harry's signs and symptoms, diagnose his condition and indicate the relationship (if any) between his present condition and his earlier sore throat.
The case shows kidney inflammation. They usually result from infections either of the lower urinary tract or, in Harry's case, from his earlier infection of a sore throat. Streptococcal infection of the throat can induce anti-streptococcal antibodies that bind to them, depositing immune complexes in the glomerular membranes. The kidney inflammation that primarily involves glomeruli is called glomerulonephritis, and if severe enough can cause permanent renal failure. In post-streptococcal glomerulonephritis, the smoky brown color of urine most commonly represents the leakage of blood cells through the damaged glomerular membrane.
An 18 year old patient has a complaint of painful urination, fever, chills, and back pain. This is her second urinary tract infection (UTI) within 5 months. How can the RN instruct the patient on prevention of another UTI?
The nurse can instruct the patient on proper hygiene measures, including wiping from front to back following urination to avoid introduction of anal bacteria, reduction in sexual activity if sexually active, and increased fluid intake to increase flushing of the urethra. The nurse should also explain that sexually transmitted infections can also inflame the urinary tract, clogging some of its ducts.
An older man sees his doctor for severe pain in his lower abdominal or flank area, elevated temperature, and nausea. Exhaustive tests rule out abdominal obstructions and infections. Plain X-rays indicate a radiopaque (whitish) spot in the area of his right ureter. Diagnose his problem. Give suggested treatment and prognosis.
The symptoms show that a kidney stone that has been passed into the ureter. Recommended treatments include be IV therapy to flush the stone out, surgery, or ultrasound waves to shatter the calculi. The usual prognosis is for complete recovery. There is a possibility of kidney stones forming again.
What are aquaporins?
They are transmembrane proteins that form water-filled pores in water-permeable portions of the convoluted tubules such as the PCT and collecting duct.
The area between the ureters and urethra is called the ________ in a bladder.
Trigone
Aldosterone is a hormone that causes the renal tubules to reclaim sodium ions from the filtrate.
True
Atrial natriuretic peptide inhibits sodium reabsorption.
True
Blood in the urine may be a symptom of bladder cancer.
True
In the absence of hormones, the distal tubule and collecting ducts are relatively impermeable to water.
True
In the kidneys, the countercurrent mechanism involves the interaction between the flow of filtrate through the nephron loop of the juxtamedullary nephrons (the countercurrent multiplier) and the flow of blood through the limbs of adjacent blood vessels (the countercurrent exchanger). This relationship establishes and maintains an osmotic gradient extending from the cortex through the depths of the medulla that allows the kidneys to vary urine concentration dramatically
True
Incontinence is the inability to control voluntary micturition.
True
Obligatory water reabsorption involves the movement of water along an osmotic gradient.
True
The act of emptying the bladder is called voiding.
True
The entire responsibility for urine formation lies with the nephron
True
The position of the kidneys behind the peritoneal lining of the abdominal cavity is described by the term retroperitoneal
True
The urethra contains an internal sphincter of smooth muscle.
True
Tubular secretion is effective in controlling blood pH.
True
Water reabsorption through the proximal convoluted tubule is termed obligatory water reabsorption, whereas water reabsorption through the distal convoluted tubule is termed facultative water reabsorption
True
Freshly voided urine has very little smell, but shortly after voiding it can give off a very strong smell. Why?
Urine is relatively sterile but if it is allowed to stand, bacteria begin to metabolize the urea solutes to release ammonia and other smells depending on the person's diet. A fruity smell generally means there is a diabetes problem.
List three substances that are abnormal urinary constituents and provide the proper clinical term for such abnormalities.
glucose (glycosuria), proteins (proteinuria or albuminuria), ketone bodies (ketonuria), hemoglobin (hemoglobinuria), bile pigments (bilirubinuria), erythrocytes (hematuria), and leukocytes (pyuria).
What clinical effects would low blood pressure have on the kidneys of a burn patient?
patient would have a much lower glomerular hydrostatic pressure due to water losses through burned skin and would have a low GFR. This is highly dangerous, leading to failure of the nephron loop to maintain countercurrent flow, flowed by anuria. It is made worse if any muscle is burned and myoglobin in the blood exceeds its transport maximum, resulting in plugging of the tubules and death of the nephron.
