85 terms

Chapter 26: The Urinary System

Which organs constitute the urinary system?
The kidneys, ureters, urinary bladder, and urethra are the components of the urinary system.
Why are the kidneys said to be retroperitoneal?
The kidneys are retroperitoneal because they are posterior to the peritoneum.
What structures pass through the renal hilum?
Blood vessels, lymphatic vessels, nerves, and a ureter pass through the renal hilum.
What volume of blood enters the renal arteries per minute?
About 1200 mL of blood enters the renal arteries each minute.
What are the basic differences between cortical and juxtamedullary nephrons?
Cortical nephrons have glomeruli in the superficial renal cortex, and their short loops of Henle penetrate only into the superficial renal medulla. Juxtamedullary nephrons have glomeruli deep in the renal cortex, and their long loops of Henle extend through the renal medulla nearly to the renal papilla.
When cells of the renal tubules secrete the drug penicillin, is the drug being added to or removed from the bloodstream?
Secreted penicillin is being removed from the bloodstream.
Which part of the filtration membrane prevents red blood cells from entering the capsular space?
Endothelial fenestrations (pores) in glomerular capillaries are too small for red blood cells to pass through.
Suppose a tumor is pressing on and obstructing the right ureter. What effect might this have on CHP and thus on NFP in the right kidney? Would the left kidney also be affected?
Obstruction of the right ureter would increase CHP and thus decrease NFP in the right kidney; the obstruction would have no effect on the left kidney.
Why is tubuloglomerular feedback termed autoregulation?
Auto- means self; tubuloglomerular feedback is an example of autoregulation because it takes place entirely within the kidneys.
What is the main function of the tight junctions between tubule cells?
The tight junctions between tubule cells form a barrier that prevents diffusion of transporter, channel, and pump proteins between the apical and basolateral membranes.
How does filtered glucose enter and leave a PCT cell?
Glucose enters a PCT cell via a sodium ion-glucose symporter in the apical membrane and leaves via facilitated diffusion through the basolateral membrane.
Which step in sodium ion movement is promoted by the electrochemical gradient?
The electrochemical gradient promotes movement of sodium ions into the tubule cell through the apical membrane antiporters.
By what mechanism is water reabsorbed from tubular fluid?
Reabsorption of the solutes creates an osmotic gradient that promotes the reabsorption of water via osmosis.
Why is the sodium ion-potassium ion-chloride ion symporter considered secondary active transport?
This is considered secondary active transport because the symporter uses the energy stored in the concentration gradient of sodium ions between extracellular fluid and the cytosol.
Does water reabsorption accompany ion reabsorption in the thick ascending limb of the loop of Henle?
No water is reabsorbed here because the thick ascending limb of the loop of Henle is virtually impermeable to water.
Which hormone stimulates reabsorption and secretion by principal cells, and how does this hormone exert its effect?
In principal cells, aldosterone stimulates secretion of potassium ions and reabsorption of sodium ions by increasing the activity of sodium-potassium pumps and number of leakage channels for sodium ions and potassium ions.
In addition to ADH, which other hormones contribute to the regulation of water reabsorption?
Aldosterone and atrial natriuretic peptide influence renal water reabsorption along with ADH.
Which portions of the renal tubule and collecting duct reabsorb more solutes than water to produce dilute urine?
Dilute urine is produced when the thick ascending limb of the loop of Henle, the distal convoluted tubule, and the collecting duct reabsorb more solutes than water.
Which solutes are the main contributors to the high osmolarity of interstitial fluid in the renal medulla?
The high osmolarity of interstitial fluid in the renal medulla is due mainly to sodium ions, chloride ions, and urea.
In which segments of the nephron and collecting duct does secretion occur?
Secretion occurs in the proximal convoluted tubule, the loop of Henle, and the collecting duct.
What is a lack of voluntary control of micturition called?
Lack of voluntary control over micturition is termed urinary incontinence.
What are the three subdivisions of the male urethra?
The three subdivisions of the male urethra are the prostatic urethra, membranous urethra, and spongy urethra.
When do the kidneys begin to develop?
The kidneys start to form during the third week of development.
What are the major functions of the kidney?
Regulation of blood ionic composition, regulation of blood pH, regulation of blood volume, regulation of blood pressure, maintenance of blood osmolarity, production of hormones, regulation of blood glucose level, and excretion of wastes and foreign substances.
This is the formation of a new glucose molecule.
What are the waste products normally excreted by the kidneys?
Urea, creatinine, bilirubin, and ammonia.
This is smooth dense irregular connective tissue that is continuous with the outer coat of the ureter.
Renal Capsule
The portion of the kidney that extends between the renal pyramids is called the
Renal Columns
Which is the order of blood flow through the kidneys?
Renal artery > segmental arteries > interlobar arteries > arcuate arteries > interlobular arteries > afferent arterioles > glomerular capillaries > efferent arterioles > peritubular capillaries > interlobular veins > arcuate veins > interlobar veins > renal vein
Which is the order of filtrate flow?
Glomerular capsule, proximal convoluted tubule (PCT), loop of Henle, distal convoluted tubule (DCT), collecting duct
Which structure of the nephron reabsorbs the most substances?
Proximal Convoluted Tubule
This is the structure of the nephron that filters blood.
Glomerular Capsule
This term means the return of substances into the blood stream from the filtrate.
This is a nephron process that results in a substance in blood entering the already formed filtrate.
This layer of filtration membrane is composed of collagen fibers and proteoglycans in a glycoprotein matrix.
Basal Lamina
This occurs when stretching triggers contraction of smooth muscle walls in afferent arterioles.
Myogenic Mechanism
This occurs when a substance passes from the fluid in the tubular lumen through the apical membrane, across the cytosol, and then into the interstitial fluid.
Transcellular Reabsorption
The proximal convoluted tubules reabsorb what percentage of filtered water?
What are the ways in which angiotensin II affects the kidneys?
It can decrease GFR, it enhances reabsorption of certain ions, and it stimulates the release of aldosterone.
Urea recycling can cause a buildup of urea in the
Renal Medulla
Increased secretion of hydrogen ions would result in a(n) ______________ of blood ____________?
Increase, pH
Increased secretion of aldosterone would result in a(n) ______________ of blood ____________?
Increase, Sodium
An analysis of the physical, chemical, and microscopic properties of urine is called
Water accounts for what percentage of the total volume of urine?
This is a test to measure kidney function.
Plasma Creatinine
This transports urine from the kidney to the bladder.
This layer of the ureter is composed of connective tissue, collagen and elastic fibers.
Lamina Propria
This lies in the anterior corner of the trigone of the bladder.
Internal Urethral Orifice
An increase in permeability of the filtration membrane due to disease, injury, or irritation of kidney cells by substances such as bacterial toxins, ether, or heavy metals indicates which condition?
Anorexia, starvation, or a diet too low in carbohydrates indicates which condition?
Stress, causing excessive amounts of epinephrine secretion which stimulates glycogen breakdown, indicates which condition? This condition can also indicate diabetes mellitus.
Excessive urine concentration of a normal breakdown product of hemoglobin, caused by pernicious anemia, infectious hepatitis, jaundice or cirrhosis, indicates which condition?
This substance gives bile its major pigmentation:
These are tiny masses of material, hardened in the lumen of the urinary tubule and are flushed out when filtrate builds up behind them:
Candida albicans and E. coli are which type of abnormal constituent of urine:
What is the normal pH range of urine in humans?
What is the normal volume of urine produced in humans?
What is the normal specific gravity range of urine in humans?
1.001 - 1.035
This hormone is released when the blood volume increases.
Atrial Natriuretic Peptide
Consumption of salty food will cause an increase in this hormone.
Absence of angiotensin converting enzyme will lead to
Decreased Blood Pressure
If the urinary excretion rate of a drug such as penicillin is greater than the rate at which it is filtered at the glomerulus, how else is it getting into the urine?
Tubular Secretion
How does the urinary system help the nervous system?
The kidneys perform gluconeogenesis, providing glucose for neurons.
Which condition is characterized by elevated blood levels of cholesterol, phospholipids and triglycerides with depressed blood levels of albumin?
Nephrotic Syndrome
What type of embryonic tissue develops into nephrons?
True or False: In the kidneys, the countercurrent mechanism involves the interaction between the flow of filtrate through the loop of Henle 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.
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
3, 6, 2, 1, 5, 4
True or False: In the absence of hormones, the distal tubule and collecting ducts are relatively impermeable to water.
True or False: Atrial naturetic peptide inhibits sodium reabsorption.
True or False: Ridding the body of bicarbonate ions is an importance feature of tubular secretion.
True or False: Tubular secretion is effective in controlling blood pH.
True or False: Obligatory water reabsorption involves the movement of water along an osmotic gradient.
The juxtaglomerular apparatus is responsible for ________.
Regulating the rate of filtrate formation and controlling systemic blood pressure.
True or False: Urea is reabsorbed in the loop of Henle.
True or False: Ureters are trilayered (mucosa, muscularis, and adventitia).
True or False: Urine is 95% water by volume.
What is the salt level-monitoring part of the nephron?
Macula Densa
What are the most important hormone regulators of electrolyte reabsorption and secretion?
Angiotensin II and Aldosterone
The mechanism that establishes the medullary osmotic gradient depends most on the permeability properties of the ________.
Loop of Henle
The renal corpuscle is made up of ________.
Bowman's Capsule and Glomerulus
True or False: Incontinence is the inability to control voluntary micturition.
A disease caused by inadequate secretion of antidiuretic hormone (ADH) by the pituitary gland with symptoms of polyuria is ________.
Diabetes Insipidus
The glomerulus differs from other capillaries in the body in that it ________.
Is drained by an efferent arteriole.
The factor favoring filtrate formation at the glomerulus is the ________.
Glomerular Hydrostatic Pressure
An increase in the permeability of the cells of the collecting tubule to water is due to a(n) ________.
Increase in the production of ADH