Chapter 26

List the organs of the urinary system and briefly state their function.

Kidneys: produce urine

Ureters: Transport urine toward the urinary bladder

Urinary Bladder: Temporarily stores urine prior to urination

Urethra: Conducts urine to exterior; in males, it also transports semen

Urination is the elimination of urine from the body. What is the medical term for urination?

micturition

Define excretion and elimination.

Excretion: The removal of metabolic wastes out of the body

Elimination: The discharge of these wastes out of the body. 

Where are the kidneys positioned in the body?

Located on either side of the vertebral column, between vertebrae T₁₂ and L₃

What endocrine gland sits on top of each kidney?

Adrenal Gland

What condition can occur if the kidney’s suspensory fibers break or become detached?

Floating Kidney

What is the hilum of the kidney? What two structures enter the hilum? What two structures exit the hilum?

A prominent media indentation; is the point of entry for the renal artery and renal nerves; point of exit for the renal vein and the ureter

What are the outer and inner regions of the kidney called? Which region contains renal pyramids?

Cortex (outer) and medulla (inner); renal medulla

What are the functional units of the kidneys called? Hint: Microscopic structures that begin urine formation.

nephrons

What is another name for the glomerular capsule?

Bowman’s capsule

Which arterioles carry blood to the glomerulus? Which arterioles carry blood away from the glomerulus?

Afferent arteriole; efferent arteriole

What is glomerulonephritis?

Inflammation of the glomeruli that impairs filtration in the kidney

Glomerulonephritis is often an immune complex disorder, but it may develop after an infection involving which genus of bacteria?

Streptococcus bacteria

What are three structures that comprise the filtration membrane?

Fenestrated endothelium, basement membrane, foot processes of podocytes

In which part of the nephron does filtration take place?

Renal corpuscle

What is filtrate? Does it contain proteins?

Filtration is when blood pressure forces water and small dissolved solutes out of the glomerular capillaries through this membrane and into the capsular space; protein free

What occurs during reabsorption? What occurs during secretion?

A substance is “reclaimed” and eventually returns to the blood; a substance enters the tubular fluid from the blood. 

What is the primary function of the proximal convoluted tubule (PCT)?

reabsorption

What is the primary function of the distal convoluted tubule (DCT)?

Reabsorb water and selected ions, as well as active secretion of undesirable substances

The juxtaglomerular complex contains a structure called the macula densa. What do the cells of the macula densa function as? (Hint: receptors)

Chemoreceptors or baroreceptors

Juxtaglomerular cells in the juxtaglomerular complex are modified smooth muscle cells in the wall of the afferent arteriole. These cells function as baroreceptors. What do they monitor? What hormone do they release?

Monitor blood pressure in the afferent arteriole; secrete renin

What is the function of intercalated cells of the collecting duct?

Regulate the acid-base balance in the blood

Identify the two types of nephrons in the kidney. Which type constitutes ~85% of all nephrons?

Cortical nephrons and juxtamedullary nephrons; cortical nephrons

What is the primary function of the ascending limb of the nephron loop?

Reabsorption of ions; assists in creation of concentration gradient in the renal medulla. 

What is the primary function of the descending limb of the nephron loop?

Reabsorption of water from tubular fluid

List three important wastes produced during metabolism.

Urea, creatinine, uric acid

List the three distinct processes that form urine in the kidney.

Filtration, reabsorption, secretion

What two transport mechanisms are used during the reabsorption of substances in the renal tubule? What process is used for reabsorption of water?

Active (carrier proteins) and passive transport (diffusion); osmosis

Which four nutrients are not detected or are detected in very small amounts (<0.2 mg/dL) in urine from a healthy adult?

Glucose, lipids, amino acids, proteins

What is the physical reason why glomerular hydrostatic pressure (GHP) is greater than hydrostatic pressure in typical systemic capillaries?

Vascular resistance at the glomerulus (arterioles = higher blood pressure)

What would happen if the glomerular hydrostatic pressure (GHP) and the hydrostatic pressure in typical systemic capillaries were equal? Hint: What process would not be able to happen in the renal corpuscle?

Glomerular filtration would not occur

What causes capsular hydrostatic pressure?

Results from the resistance to flow along the nephron and the conducting system.

How is net hydrostatic pressure (NHP) calculated?

NHP = (GHP - CsHP)   (50mmHg - 15mmHg) = 35mmHg

What organic molecule is responsible for blood colloid osmotic pressure (BCOP)?

Proteins

How is net filtration pressure (NFP) calculated?

NFP = NHP - BCOP

Define glomerular filtration rate.

The amount of filtrate the kidneys produce each minute

Autonomic regulation of filtration is primarily maintained by which division of the autonomic nervous system?

Sympathetic Division

What process is regulated by hormones of RAAS and natriuretic peptides?

Glomerular Filtration Rate

Define renal threshold.

The plasma concentration at which a specific substance or ion begins to appear in the urine.

Define glycosuria

Glucose in the urine

Which part of the renal tubule normally reabsorbs 60–70 percent of the volume of the filtrate produced in the renal corpuscle?

Proximal convoluted tubule 

Which limb of the nephron loop is impermeable to water?

Ascending limb

Which part of the nephron is responsible for the active secretion of ions, acids, drugs, and toxins into the tubule?

Distal Convoluted Tubule

Which of the following activities is not related to kidney function?

• lipid digestion

• regulation of blood pressure

• control of wastes in the blood

• control of hydrogen ion and pH in the blood

lipid digestion

When the bladder is full, urine is eliminated through the process known as

defecation.

emesis.

segmentation.

beta-oxidation.

micturition.

micturition

A glomerulus is

• the horseshoe-shaped segment of the nephron.

• the expanded end of a nephron.

• attached to the collecting duct.

• a knot of capillaries within the renal corpuscle.

• the source of erythropoietin.

a knot of capillaries within the renal corpuscle.

the cavity of the kidney that receives urine from the calyces is called the

renal medulla.

renal sinus.

renal cortex.

renal papilla.

renal pelvis

renal pelvis

The condition called ________ is especially dangerous because the ureters or renal blood vessels can become twisted or kinked during movement.

pyelonephritis

floating kidney

renal failure

polycystic kidney disease

renal calculi

floating kidney

Capillaries that surround the proximal convoluted tubules are

proximal capillaries.

efferent arterioles.

corticoradiate capillaries.

vasa recta capillaries.

peritubular capillaries.

peritubular capillaries

The glomerular (Bowman's) capsule and the glomerulus make up the

renal pyramid.

collecting tubule system.

renal corpuscle.

renal papilla.

nephron loop (loop of Henle).

renal corpuscle

you have been diagnosed with lupus erythematosus, a severe autoimmune disorder with a wide variety of organ-related disorders. Your doctor is worried about how this will affect your kidney function. He says that you are susceptible to ________ because of the lupus.

pyelonephritis

glomerulonephritis

cystitis

renal calculi

polycystic kidney disease

glomerulonephritis

Filtrate first passes from the glomerular capsule to the

• collecting duct.

• proximal convoluted tubule.

• nephron loop (loop of Henle).

• minor calyx.

• distal convoluted tubule

proximal convoluted tubule

The primary function of the proximal convoluted tubule is

• adjusting the urine pH.

• secretion of drugs.

• secretion of acids and ammonia.

• reabsorption of ions, organic molecules, vitamins, and water.

• filtration.

reabsorption of ions, organic molecules, vitamins, and water.

The majority of glomeruli are located in the ________ of the kidney.

calyces

vasa recta

cortex

medulla

pelvis

cortex

Blood is directly supplied to a nephron by its __________.

efferent arterioles

renal arteries

cortical radiate arteries

afferent arterioles

afferent arterioles

The urinary filtrate first enters __________.

the collecting tubule

the glomerular (Bowman) capsule

the renal papilla

the proximal convoluted tubule

the glomerular (Bowman) capsule

________ is the most abundant organic waste.

Carbon dioxide

Creatinine

Uric acid

Urea

Ammonia

Urea

One of the organic substances not normally excreted by the kidney is __________.

urea

uric acid

protein

creatinine

protein

Sheila has been exercising at peak performance for about 60 minutes. She did not hydrate as effectively as she should have and as a result, her urine is deep yellow and low in volume. Which of the following is the most likely mechanism affecting this?

blood colloid osmotic pressure

net filtration pressure

glomerular hydrostatic pressure

capsular colloid osmotic pressure

blood colloid osmotic pressure

Which of these effects is NOT produced by sympathetic activation?

increased glomerular filtration rate

renin release

altered regional blood flow

vasoconstriction of the afferent arteriole

increased glomerular filtration rate

The process of filtration is driven mainly by

glomerular hydrostatic pressure.

blood colloid osmotic pressure.

solvent drag.

active transport.

renal pumping.

glomerular hydrostatic pressure

The main force that causes filtration in a nephron is

glomerular hydrostatic pressure.

blood colloid osmotic pressure.

osmotic pressure of the urine.

capsular hydrostatic pressure.

capsular colloid osmotic pressu

glomerular hydrostatic pressure

A drug that inhibits angiotensin converting enzyme (ACE) may lead to all of the following except

less secretion of aldosterone.

decreased sodium reabsorption.

increased urinary loss of sodium.

reduction of blood pressure.

increased fluid retention.

increased fluid retention

A decrease in blood albumin level will cause a decrease in blood colloid osmotic pressure. This will lead to a rise in the net glomerular filtration pressure. Are these two statements true or false?

The first is true; the second is false.

Both statements are true.

Both statements are false.

The first is false; the second is true.

Both statements are true

Secretion of hydrogen ion by the PCT is by the process of

facilitated diffusion.

active transport.

cotransport.

diffusion.

countertransport.

countertransport

Chloride ions are reabsorbed in the thick ascending limb of the nephron loop by

countertransport with bicarbonate ion.

facilitated diffusion.

cotransport with Na and K ions.

active transport.

simple diffusion.

cotransport with Na and K ions

The ________ is the plasma concentration at which a specific compound will begin appearing in the urine.

renal threshold

tubular maximum

hydrostatic threshold

blood colloid maximum

osmotic pressure

renal threshold

The process of ________ involves a carrier protein transporting a molecule down its concentration gradient.

simple diffusion

osmosis

facilitated diffusion

bulk transport

active transport

facilitated diffusion

A transport mechanism that can move a substance against a concentration gradient by using cellular energy is

bulk transport.

facilitated diffusion.

osmosis.

active transport.

simple diffusion.

active transport

The ________ test is often used to estimate the glomerular filtration rate.

glucose tolerance

creatinine clearance

specific gravity

inulin

CBC or complete blood count

creatinine clearance

What occurs in the countercurrent multiplier process?

A higher sodium concentration is produced in the renal medulla that osmotically draws water out of the tubules and urine.

Sodium is pumped into the blood while potassium is actively transported out of the blood back into the tissues.

Creatinine is actively transported out of the blood into urine.

Glucose and sodium are cotransported from urine back into blood.

Uric acid is excreted into the kidney tubules while urea

A higher sodium concentration is produced in the renal medulla that osmotically draws water out of the tubules and urine.

A patient consistently produces a large volume of dilute urine. This may be due to

dilation of the afferent arterioles.

excess aldosterone.

excess ADH.

hematuric oliguria.

absence of ADH.

absence of ADH

When the level of ADH (antidiuretic hormone) decreases,

the osmolarity of the urine decreases.

permeability to water in the collecting system increases.

water reabsorption increases in the nephron loop.

a concentrated urine is produced.

less urine is produced.

the osmolarity of the urine decreases.

Which of these is NOT a property of countercurrent multiplication?

It exploits the structure of the nephron loop.

It creates a hyperosmotic peritubular fluid in the kidney medulla.

It depends on active ion transport to function.

It is opposed by the vasa recta.

It is opposed by the vasa recta.

The detrusor muscle

compresses the urethra expelling urine.

functions as the external urethral sphincter.

compresses the urinary bladder expelling urine.

surrounds the renal pelvis.

moves urine along the ureters by peristalsis.

compresses the urinary bladder expelling urine.

The inability of the kidneys to excrete adequately to maintain homeostasis is

hematuria.

polycystic kidney disease.

renal failure.

glomerulonephritis.

calculi.

renal failure

Insoluble deposits that form within the urinary tract from calcium salts, magnesium salts, or uric acid are called kidney stones or renal

calculi.

caries.

otoliths.

lithotrophs.

plaque.

calculi

Your doctor has diagnosed you with prostatitis, an inflammation and swelling of the prostate gland. One of your primary symptoms is

hematuria.

large amounts of dilute urine.

renal failure.

glycosuria.

urinating small volumes.

urinating small volumes