Anatomy, Ch 24: Urinary System

Which structures cushion and support the kidneys against blows and help hold the kidneys in place? (Click on all correct answers to receive full credit.)

pararenal fat perirenal fat

Where does blood flow immediately after it leaves the cortical radiate arteries in the kidneys?

afferent glomerular arteriole

The uniqueness of the glomerulus, when compared to other capillary beds, is that it is both fed and drained by __________.

arterioles

Which microscopic structure functions in concentrating urine by removing water from it?

collecting duct

What is the function of the collecting duct portion of the uriniferous tubule?

concentrating urine by removing water from it

Which of the following pathways best depicts the correct flow of blood through the kidneys?

cortical radiate vein, arcuate vein, interlobar vein, renal vein

The wall of the thick ascending limb of the loop of Henle is simple __________ epithelium.

cuboidal

The kidneys' position in the superior lumbar region of the posterior abdominal wall is __________.

retroperitoneal

Match the urinary process to its description. 1) filtration 2) resorption 3) secretion 4) micturition

1) filtration: C. fluid that contains all the small molecules of blood plasma leaves the kidney capillaries and enters the nephron 2) resorption: A. most of the nutrients, water, and essential ions are recovered from the filtrate and returned to the blood of surrounding capillaries 3) secretion: D. active process in which additional undesirable molecules are moved into the tubule from the blood of surrounding capillaries 4) micturition: B. contraction of the detrusor muscle and abdominal wall muscles raise intra-abdominal pressure and facilitate emptying the bladder

Match the tubular structure to its histological description. 1) proximal convoluted tubule 2) nephron loop (thin segment) 3) distal convoluted tubule 4) papillary duct

1) proximal convoluted tubule: D. walls formed by simple cuboidal epithelial cells whose luminal surfaces have an abundance of long microvilli 2) nephron loop (thin segment): A. walls formed by simple squamous epithelial cells 3) distal convoluted tubule: C. walls formed by simple cuboidal epithelial cells whose luminal surfaces do not have abundant microvilli 4) papillary duct: B. walls formed by simple columnar epithelial cells, which contain few organelles

Match the urinary disorder to its corresponding description. 1) pyelitis 2) cystitis 3) renal calculi

1) pyelitis: B. an inflammation of the renal pelvis and calices 2) cystitis: C. an infection of the bladder 3) renal calculi: A. a condition characterized by crystallization and precipitation of calcium, magnesium, or uric acid salts in the urine

Match the term with its definition or characterization. 1) renal agenesis 2) horseshoe kidney 3) ectopic kidney 4) pelvic kidney

1) renal agenesis: B. failure of the metanephros to develop 2) horseshoe kidney: A. usually harmless, but can be associated with obstructed drainage and hydronephrosis 3) ectopic kidney: D. a kidney that fails to ascend into its normal position 4) pelvic kidney: C. one of the two kidneys in this position may block the birth canal, causing difficulty while giving birth

Match the structure of the urinary system with its description. 1) urachus 2) trigone 3) ureter 4) renal medulla 5) renal sinus 6) major calices

1) urachus: C. closed remnant of the allantois 2) trigone: D. the region defined by the openings of the ureters and the urethra 3) ureter: A. muscularis consists of inner longitudinal and outer circular layers 4) renal medulla: E. consists of cone-shaped pyramids 5) renal sinus: B. large space within the medial part of the kidney that contains renal vessels, nerves, and fat 6) major calices: F. branching extensions of the renal pelvis

Match the micturition dysfunction with its physiological description. 1) urge incontinence 2) stress incontinence 3) overflow incontinence 4) urinary retention

1) urge incontinence: B. detrusor muscle has uncontrolled contractions 2) stress incontinence: D. urethral sphincter mechanisms are malfunctioned 3) overflow incontinence: C. bladder overfills and urine dribbles from the urethra 4) urinary retention: A. a condition common in patients recovering from surgeries involving general anesthesia

Match the epithelial tissue with its location in the urinary system. 1) urinary bladder 2) distal end of urethra 3) mid-urethra (particularly in males) 4) thin limb of the loop of Henle 5) proximal convoluted tubule 6) distal convoluted tubule

1) urinary bladder: F. transitional epithelium 2) distal end of urethra: B. stratified squamous epithelium 3) mid-urethra (particularly in males): D. pseudostratified columnar epithelium 4) thin limb of the loop of Henle: C. simple squamous epithelium 5) proximal convoluted tubule: E. simple cuboidal epithelium with long microvilli 6) distal convoluted tubule: A. simple cuboidal epithelium (no microvilli)

About __________% of the fluid leaving the glomerulus enters the glomerular capsular space.

20% 20% of fluid leaving the glomerulus enters the capsular space. Most of the fluid is resorbed in the uriniferous tubules and returned to blood, and only 1% eventually becomes urine.

How many segmental arteries enter each human kidney?

5

Which of the following events occur when the posterior pituitary gland secretes antidiuretic hormone (ADH)? (Choose the two correct answers for full credit.)

A decreased volume of urine is produced. The collecting ducts and distal convoluted tubules become more permeable to water, which results in water being resorbed into blood vessels

Which of the following is/are among the predisposing factors for renal calculi?

All of the listed responses are correct. Options: -oversaturation of the renal filtrate with calcium ions, uric acid, or oxalate -abnormal acidity or alkalinity of the urine -dehydration or bacterial infection -blockage of urine flow in the urinary tract See "Disorders of the Urinary System," pages 736-737.

Each nephron is composed of which of the following structures?

All of the listed responses are correct. Options: -renal corpuscle -proximal convoluted tubule -loop of Henle -distal convoluted tubule

Why is blood pressure in the glomerulus higher than in other capillary beds?

Arterioles are high-resistance blood vessels, and the efferent glomerular arteriole is narrower than the afferent glomerular arteriole.

Quentin, an orphan as a child, is scheduled for a kidney transplant. With no living relative or spouse, he wonders about the success rate and fate of his diseased kidneys once they are removed. What could you tell him about kidney transplants?

As with 70% of kidney recipients, Quentin will receive his donor kidney from a cadaver, a deceased person whose kidneys can be maintained for about 36 hours after death. This common procedure has a high success rate (70% survival after three years, if from a cadaveric transplant) and is comparatively easy to perform, since only a few vessels need to be cut and re-joined. The procedure often entails the transplant of one new kidney into the right iliac fossa, due to its accessibility and "roominess;" and the diseased kidneys are usually left in place, not removed.

True or False: The ureters play a passive role in transporting urine from the kidneys to the bladder because gravity alone acts to propel the urine.

False

Each ureter begins superiorly, at which vertebral level?

L2

When one changes an infant or toddler girl's diaper, one should always wipe the genital region in the anterior to posterior direction, to prevent spreading fecal bacteria into the urinary tract. What may be the consequences if this rule is not followed?

Pyelonephritis, an infection of the renal pelvis and calices that has spread to the rest of the kidney, usually results from the spread of the fecal bacterium Escherichia coli from the anal region superiorly through the urinary tract. In severe cases, the kidney swells and scars, abscesses form, and the renal pelvis fills with pus. If left untreated, the infected kidneys may be severely damaged, but timely administration of antibiotics usually achieves a total cure.

Forty-five-year-old Sam suddenly experienced a sharp pain in his left side. The excruciating pain caused him to "double up" and prompted a trip to the hospital emergency room. When asked by the ER physician to describe the onset of pain, Sam said he first felt a slight pain between his ribs and hip bone, and it gradually increased in severity until it was unbearable. The pain lasted approximately 30 minutes and then suddenly eased. He further explained that the pain comes and goes, but it seemed to be moving inferiorly toward his groin. What was the physician's diagnosis?

Sam's pain was caused by renal calculi (kidney stones), which are calcium, magnesium, or uric acid salts that have crystallized and precipitated in the urine. Most calculi are <5 mm in diameter and can, thus, pass through the urinary tract without trouble. The calculi can cause pain, though, when they obstruct a ureter, thereby blocking the drainage of urine and increasing intrarenal pressure. Severe pain results when the contracting walls of the ureter contact the sharp calculi during their periodic peristaltic contractions. Pain from kidney stones radiates from the lateral abdominal region to the anterior abdominal wall and then, perhaps, to the groin.

__________ is an active process that moves additional undesirable molecules from the blood of surrounding capillaries into the uriniferous tubules.

Secretion

Elderly people tend to suffer from increased frequency of urination. What physiological changes are occurring in the urinary system of such people?

The urinary bladder of an aged person is usually shrunken, and the desire to urinate is often delayed. The loss of muscle tone in the bladder causes an annoying increased frequency of urination. Additional age-related problems are incontinence and, in males, possible urethral constriction by an enlarged prostate gland. Kidney function also declines with age because the kidneys shrink in size, the nephrons decrease in size and number, and the tubules become less efficient at secretion and reabsorption.

If the metanephric kidneys are not producing an adequate volume of urine from month 3 of fetal life in utero, what is a potential result?

The volume of amniotic fluid would be low or inadequate.

Why are the regions of L2, the sacroiliac joint, and the site where the ureters join the urinary bladder particularly susceptible places for kidney stones to lodge in the ureters?

These regions have narrower diameters than other regions of the ureter.

What is the function of the vasa recta?

They are an important part of the kidney's urine-concentrating mechanism found surrounding the loops of Henle of juxtamedullary nephrons.

The glomerular filtration membrane, which lies between the blood in the glomerular capsule and the capsular space, consists of three layers formed by the fenestrated endothelium of the capillary, the filtration slits between the pedicels of the podocytes, and an intervening basement membrane.

True

True or False: Control of the voluntary external urethral sphincter is attained as the nervous system matures. By 15 months, most toddlers are aware of having voided.

True

True or False: The human embryo develops not just one pair of kidneys, but three pairs, one after another, starting cranially and proceeding caudally.

True

True or False: The internal urethral sphincter is a thickening of the detrusor muscle at the bladder-urethra junction, and is comprised of smooth muscle, which functions in keeping the urethra closed when urine is not being passed.

True

Which of the following nitrogenous wastes produced by the kidneys is correctly paired with the substance and process from which it derives?

Uric acid / results from turnover of nucleic acids.

Don suffers from alcoholism and often winds up in the hospital being treated for injuries, and especially for dehydration after long bouts of binge drinking. After finally sobering up and joining a support group, he asks his therapist why he would always become dehydrated even though he was always drinking alcoholic beverages. How would you explain the dehydration?

When the body needs to conserve water, the pituitary gland secretes antidiuretic hormone (ADH), which increases the permeability of the collecting ducts and distal convoluted tubule to water. As a result, water is resorbed from the filtrate in these tubules into the surrounding blood vessels, decreasing the total volume of urine production. Alcohol inhibits ADH release, resulting in decreased water resorption from the renal tubules. This effect then leads to the production of copious amounts of dilute urine and, hence, the potential for dehydration.

The glomerulus is fed and drained by which structure(s)?

afferent arteriole and efferent arteriole

In which ways do the pons, cerebral cortex, or other regions of the CNS inhibit micturition? (Click on all correct answers for full credit.)

by activating sympathetic pathways that stimulate the internal urethral sphincter to contract by activating sympathetic pathways that relax the detrusor by stimulating somatic motor neurons to the external urethral sphincter, causing it to contract

Contraction of the bladder's __________ squeezes urine from the bladder during urination.

detrusor

Which of the following muscles is/are used to inhibit urination voluntarily until the proper time?

external urethral sphincter

The thin, tough supportive tissue layer called the __________ maintains the shape of the kidney and forms a barrier on the kidney's surface that can inhibit the spread of infection from surrounding areas.

fibrous capsule renal capsule

The bladder wall has how many layers?

four

The only region of the nephron in which filtration takes place is the __________.

glomerulus renal corpuscle

The renal vein exits the kidney at the __________ and empties into the inferior vena cava.

hilum

Which brain region enables a conscious decision that it is safe to micturate?

inferior frontal region of cerebral cortex

The filtration membrane __________.

is the actual filter that lies between the blood in the glomerulus and the capsular space

Within the nephron, the __________ is the structure that functions in regulating blood pressure.

juxtaglomerular complex

Which of the following pathways best depicts the correct flow of urine through the kidney tubules?

loop of Henle, distal convoluted tubule, papillary duct, minor calyx, renal pelvis See "Renal Tubule," pages 727-728 and Figure 24.7

The kidneys are positioned retroperitoneally in the superior __________ region of the posterior abdominal wall.

lumbar

Which of the following urethral regions in the human male run(s) for about 2.5 cm through the membranelike urogenital diaphragm?

membranous urethra

__________ cells show contractile properties and regulate blood flow within the glomerulus.

mesangial

Which renal cells regulate blood flow within the glomerulus through their contractile properties?

mesangial cells

During embryological development, the first pair of kidneys degenerates and is replaced by the __________.

mesonephros

Which embryonic structure becomes the definitive kidney?

metanephros

The renal plexus is supplied by sympathetic fibers from the __________.

most inferior thoracic splanchnic nerve and the first lumbar splanchnic nerve

Kidney cancer risk factors include __________, high blood pressure, and perhaps a high protein diet.

obesity

All molecules that are secreted by the nephrons into the urine are from the blood of __________.

peritubular capillaries

The parietal layer of the glomerular capsule __________.

plays no role in formation of filtrate

The visceral layer of the glomerular capsule clings to the glomerulus and consists of unusually shaped cells called __________.

podocytes

The micturition center is located in the __________.

pons

The oblique entry of the ureters into the bladder __________.

prevents backflow of urine into the ureters from the urinary bladder

Which structures are inward extensions of the renal cortex?

renal columns

Which structure(s) is/are confined to the renal cortex?

renal corpuscle, proximal convoluted tubule, and distal convoluted tubule

Juxtaglomerular (granular) cells secrete __________ in response to falling blood pressure in the afferent arteriole.

renin

The proximal convoluted tubule is most active in __________.

resorption and secretion

Which of the following sequences correctly traces the vascular pathway beginning after the renal artery?

segmental artery, interlobar artery, arcuate artery, cortical radiate artery, afferent glomberular arteriole, glomerulus, efferent glomerular arteriole

If a patient were exhibiting uncontrolled contractions of the detrusor, he or she would be said to have __________.

urge incontinence

Which of the following nitrogenous waste products excreted in the urine results from the turnover of nucleic acids?

uric acid

The trigone is located in which urinary structure(s)?

urinary bladder