Human Body Chapter 25
Chapter 25
- 1.
The mechanism that establishes the medullary osmotic gradient depends most on the permeability properties of the ________.
- A.
Distal convoluted tubule
- B.
Glomerular filtration membrane
- C.
Collecting duct
- D.
Loop of Henle
Correct Answer
D. Loop of HenleExplanation
The mechanism that establishes the medullary osmotic gradient depends most on the permeability properties of the loop of Henle. The loop of Henle plays a crucial role in the reabsorption of water and solutes from the filtrate. It creates a concentration gradient in the medulla of the kidney, with the descending limb allowing water to passively leave the tubule and the ascending limb actively transporting ions out of the tubule. This concentration gradient is essential for the reabsorption of water in the collecting ducts and the production of concentrated urine.Rate this question:
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- 2.
Urine passes through the ________.
- A.
Renal hilum to the bladder to the ureter
- B.
Pelvis of the kidney to ureter to bladder to urethra
- C.
Hilum to urethra to bladder
- D.
Glomerulus to ureter to renal tubule
Correct Answer
B. Pelvis of the kidney to ureter to bladder to urethraExplanation
Urine is produced in the kidneys and then passes through the renal hilum, which is a narrow opening in the kidney, into the pelvis of the kidney. From there, it travels through the ureter, which is a tube that connects the kidney to the bladder. Once in the bladder, urine is stored until it is ready to be eliminated from the body through the urethra. Therefore, the correct answer is "pelvis of the kidney to ureter to bladder to urethra."Rate this question:
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- 3.
Which of the following is not associated with the renal corpuscle?
- A.
An efferent arteriole
- B.
A vasa recta
- C.
A fenestrated capillary
- D.
A podocyte
Correct Answer
B. A vasa rectaExplanation
The renal corpuscle is a part of the kidney responsible for filtering blood and forming urine. It consists of the glomerulus, a network of fenestrated capillaries, and the Bowman's capsule. The efferent arteriole carries blood away from the glomerulus, while the vasa recta is a network of blood vessels that surrounds the nephron. Podocytes are specialized cells in the Bowman's capsule that help with filtration. The only option that is not associated with the renal corpuscle is the vasa recta, as it is not a component of the corpuscle but rather surrounds the nephron.Rate this question:
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- 4.
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.
Decrease in the concentration of the blood plasma
- C.
Increase in the production of ADH
- D.
Increase in the production of aldosterone
Correct Answer
C. Increase in the production of ADHExplanation
An increase in the production of ADH (antidiuretic hormone) causes an increase in the permeability of the cells of the collecting tubule to water. ADH acts on the collecting tubule to make it more permeable to water, allowing for increased reabsorption of water from the urine back into the bloodstream. This results in a decrease in urine output and helps to conserve water in the body.Rate this question:
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- 5.
The urinary bladder is composed of ________ epithelium.
- A.
Stratified squamous
- B.
Pseudostratified columnar
- C.
Transitional
- D.
Simple squamous
Correct Answer
C. TransitionalExplanation
The urinary bladder is composed of transitional epithelium. This type of epithelium is specialized to stretch and accommodate changes in volume. The transitional epithelium allows the bladder to expand as it fills with urine and then contract as it empties. This type of epithelium is also found in other organs of the urinary system, such as the ureters and the urethra, where it allows for the passage of urine without damage to the underlying tissues.Rate this question:
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- 6.
The kidneys are stimulated to produce renin ________.
- A.
When the specific gravity of urine rises above 1.10
- B.
By a decrease in the blood pressure
- C.
When the pH of the urine decreases
- D.
When the peritubular capillaries are dilated
Correct Answer
B. By a decrease in the blood pressureExplanation
The kidneys are stimulated to produce renin by a decrease in blood pressure. Renin is an enzyme that plays a role in regulating blood pressure. When blood pressure drops, the kidneys detect this decrease and respond by releasing renin. Renin then initiates a series of reactions that ultimately lead to the production of angiotensin II, a hormone that helps to increase blood pressure. Therefore, a decrease in blood pressure triggers the release of renin to help restore and maintain normal blood pressure levels.Rate this question:
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- 7.
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.
Maintains blood osmolarity
- C.
Regulates blood glucose levels and produces hormones
- D.
Eliminates solid, undigested wastes and excretes carbon dioxide, water, salts, and heat
Correct Answer
D. Eliminates solid, undigested wastes and excretes carbon dioxide, water, salts, and heatExplanation
The urinary system is responsible for maintaining homeostasis by controlling the composition, volume, and pressure of blood. It also helps maintain blood osmolarity and regulates blood glucose levels by producing hormones. However, the elimination of solid, undigested wastes and excretion of carbon dioxide, water, salts, and heat is primarily the function of the digestive and respiratory systems, not the urinary system.Rate this question:
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- 8.
Which gland sits atop each kidney?
- A.
Pancreas
- B.
Pituitary
- C.
Adrenal
- D.
Thymus
Correct Answer
C. AdrenalExplanation
The adrenal gland sits atop each kidney. It is responsible for producing hormones such as adrenaline and cortisol, which play a crucial role in regulating various bodily functions, including metabolism, blood pressure, and stress response. The pancreas is located in the abdomen and is responsible for producing insulin and digestive enzymes. The pituitary gland is located at the base of the brain and controls the release of hormones from other glands. The thymus gland is located in the chest and plays a role in the development of the immune system.Rate this question:
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- 9.
The ________ artery lies on the boundary between the cortex and medulla of the kidney.
- A.
Interlobar
- B.
Cortical radiate
- C.
Lobar
- D.
Arcuate
Correct Answer
D. ArcuateExplanation
The arcuate artery is the correct answer because it is the artery that lies on the boundary between the cortex and medulla of the kidney. The interlobar artery is located within the renal columns, the cortical radiate artery branches off the interlobar artery and enters the cortex, and the lobar artery branches off the interlobar artery and supplies blood to the renal lobes. Therefore, the arcuate artery is the only artery that fits the description given in the question.Rate this question:
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- 10.
The glomerulus differs from other capillaries in the body in that it ________.
- A.
Is impermeable to most substances
- B.
Has a basement membrane
- C.
Has a blood pressure much lower than other organ systems
- D.
Is drained by an efferent arteriole
Correct Answer
D. Is drained by an efferent arterioleExplanation
The glomerulus is a network of capillaries located in the kidney. It is unique because it is drained by an efferent arteriole, which carries blood away from the glomerulus. This is different from other capillaries in the body, which are typically drained by venules. The efferent arteriole helps to maintain a high pressure within the glomerulus, allowing for the filtration of blood and the formation of urine.Rate this question:
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- 11.
The descending limb of the loop of Henle ________.
- A.
Is freely permeable to sodium and urea
- B.
Is not permeable to water
- 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
Correct Answer
D. Contains fluid that becomes more concentrated as it moves down into the medullaExplanation
The descending limb of the loop of Henle contains fluid that becomes more concentrated as it moves down into the medulla. This is because the descending limb is permeable to water, allowing water to leave the tubule by osmosis. As water leaves, the concentration of solutes in the tubule increases, leading to a more concentrated fluid in the medulla.Rate this question:
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- 12.
Select the correct statement about the ureters.
- A.
The ureter is innervated by parasympathetic nerve endings only.
- B.
Ureters contain sphincters at the entrance to the bladder to prevent the backflow of urine.
- C.
The epithelium is stratified squamous like the skin, which allows a great deal of stretch.
- D.
The ureters are capable of peristalsis like that of the gastrointestinal tract.
Correct Answer
D. The ureters are capable of peristalsis like that of the gastrointestinal tract.Explanation
The ureters are capable of peristalsis like that of the gastrointestinal tract. Peristalsis is the wave-like muscle contractions that help propel urine from the kidneys to the bladder. This movement is essential for the proper functioning of the urinary system and the elimination of waste from the body. The other statements are incorrect because the ureters are not innervated by parasympathetic nerve endings only, they contain sphincters to prevent backflow, and their epithelium is not stratified squamous like the skin.Rate this question:
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- 13.
The fatty tissue surrounding the kidneys is important because it ________.
- A.
Is necessary as a barrier between the adrenal glands and kidneys
- B.
Stabilizes the position of the kidneys by holding them in their normal position
- C.
Ensures adequate energy for the adrenal glands to operate efficiently
- D.
Produces vitamin D
Correct Answer
B. Stabilizes the position of the kidneys by holding them in their normal positionExplanation
The fatty tissue surrounding the kidneys acts as a cushion and support system for the kidneys, helping to stabilize their position and hold them in their normal position. This is important because it ensures that the kidneys are properly aligned and positioned within the body, allowing them to function optimally.Rate this question:
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- 14.
The renal corpuscle is made up of ________.
- A.
The renal papilla
- B.
The descending loop of Henle
- C.
The renal pyramid
- D.
Bowman's capsule and glomerulus
Correct Answer
D. Bowman's capsule and glomerulusExplanation
The renal corpuscle is the functional unit of the kidney responsible for filtering blood and forming urine. It consists of two main components: Bowman's capsule and glomerulus. Bowman's capsule is a cup-like structure that surrounds the glomerulus, which is a network of tiny blood vessels called capillaries. Together, Bowman's capsule and glomerulus work to filter waste products and excess fluids from the blood, allowing them to be excreted as urine. Therefore, the correct answer is Bowman's capsule and glomerulus.Rate this question:
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- 15.
The functional and structural unit of the kidneys is the ________.
- A.
Glomerular capsule
- B.
Loop of Henle
- C.
Basement membrane of the capillaries
- D.
Nephron
Correct Answer
D. NephronExplanation
The nephron is the functional and structural unit of the kidneys. It is responsible for filtering waste products and excess water from the blood to form urine. Each kidney contains millions of nephrons, which consist of a glomerulus and a tubule. The glomerulus filters blood, while the tubule reabsorbs essential substances and excretes waste products. Therefore, the nephron plays a crucial role in maintaining the body's fluid balance and removing waste materials.Rate this question:
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- 16.
The juxtaglomerular apparatus is responsible for ________.
- A.
The secretion of drugs
- B.
The secretion of acids and ammonia
- C.
Regulating the rate of filtrate formation and controlling systemic blood pressure
- D.
Reabsorption of organic molecules, vitamins, and water
Correct Answer
C. Regulating the rate of filtrate formation and controlling systemic blood pressureExplanation
The juxtaglomerular apparatus is a part of the kidney that plays a crucial role in regulating the rate of filtrate formation and controlling systemic blood pressure. It is involved in the release of renin, an enzyme that helps to regulate blood pressure by constricting blood vessels and increasing the production of aldosterone, a hormone that promotes sodium and water reabsorption. This mechanism helps to maintain the balance of fluid and electrolytes in the body and regulate blood pressure.Rate this question:
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- 17.
The chief force pushing water and solutes out of the blood across the filtration membrane is ________.
- A.
The thickness of the capillary endothelium
- B.
Glomerular hydrostatic pressure (glomerular blood pressure)
- C.
The size of the pores in the basement membrane of the capillaries
- D.
The design and size of the podocytes
Correct Answer
B. Glomerular hydrostatic pressure (glomerular blood pressure)Explanation
The correct answer is glomerular hydrostatic pressure (glomerular blood pressure). This pressure is the main force that pushes water and solutes out of the blood across the filtration membrane in the kidneys. It is generated by the pressure exerted by the heart on the blood vessels, specifically in the glomerulus of the kidney. This pressure is essential for the filtration process, allowing waste products and excess fluids to be removed from the blood and excreted as urine.Rate this question:
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- 18.
Which of the following statements describes the histology of the ureters?
- A.
They are actually an extension of the visceral peritoneum.
- B.
They are made up entirely of muscle tissue because they need to contract in order to transport urine efficiently.
- C.
They are made up of several layers of endothelium.
- D.
They are trilayered (mucosa, muscularis, and adventitia).
Correct Answer
D. They are trilayered (mucosa, muscularis, and adventitia).Explanation
The correct answer is that the ureters are trilayered (mucosa, muscularis, and adventitia). This means that they have three distinct layers: the innermost mucosa, which is responsible for absorption and secretion; the middle muscularis, which consists of smooth muscle and allows the ureters to contract and propel urine; and the outer adventitia, which provides structural support. This trilayered structure is important for the efficient transport of urine from the kidneys to the bladder.Rate this question:
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- 19.
Which of the following statements is a false or incorrect statement?
- A.
The male urethra serves both the urinary and reproductive systems at the same time.
- B.
The male urethra is longer than the female urethra.
- C.
The male urethra serves both the urinary and reproductive systems but at different times.
- D.
The male urethra is a passageway for both urine and semen.
Correct Answer
A. The male urethra serves both the urinary and reproductive systems at the same time.Explanation
The male urethra serves both the urinary and reproductive systems but at different times.Rate this question:
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- 20.
Which of the following acts as the trigger for the initiation of micturition (voiding)?
- A.
The pressure of the fluid in the bladder
- B.
The stretching of the bladder wall
- C.
The sympathetic efferents
- D.
Motor neurons
Correct Answer
B. The stretching of the bladder wallExplanation
The stretching of the bladder wall acts as the trigger for the initiation of micturition (voiding). When the bladder becomes stretched due to the accumulation of urine, sensory receptors in the bladder wall send signals to the brain, indicating the need to empty the bladder. This triggers the micturition reflex, leading to the contraction of the bladder muscles and relaxation of the urinary sphincters to allow urine to be expelled from the body.Rate this question:
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- 21.
The filtration membrane includes all except ________.
- A.
Basement membrane
- B.
Renal fascia
- C.
Glomerular endothelium
- D.
Podocytes
Correct Answer
B. Renal fasciaExplanation
The filtration membrane is a structure in the kidney responsible for filtering waste products from the blood. It consists of three layers: the basement membrane, glomerular endothelium, and podocytes. The basement membrane acts as a physical barrier, preventing the passage of large molecules. The glomerular endothelium is a layer of cells that allows for the passage of small molecules. Podocytes are specialized cells that wrap around the glomerular capillaries and help regulate the filtration process. Renal fascia, on the other hand, is a layer of connective tissue that surrounds and supports the kidney, but it is not a part of the filtration membrane.Rate this question:
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- 22.
The mechanism of water reabsorption by the renal tubules is ________.
- A.
Solvent drag
- B.
Osmosis
- C.
Cotransport with sodium ions
- D.
Active transport
Correct Answer
B. OsmosisExplanation
Osmosis is the process by which water molecules move across a semipermeable membrane from an area of lower solute concentration to an area of higher solute concentration. In the context of the renal tubules, osmosis is responsible for the reabsorption of water from the filtrate back into the bloodstream. As the filtrate moves through the tubules, solutes such as sodium ions are actively transported out of the tubules, creating a higher solute concentration in the surrounding interstitial fluid. This concentration gradient drives the movement of water out of the tubules and into the interstitial fluid through osmosis, leading to water reabsorption.Rate this question:
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- 23.
Most electrolyte reabsorption by the renal tubules is ________.
- A.
Hormonally controlled in distal tubule segments
- B.
In the distal convoluted tubule
- C.
Completed by the time the loop of Henle is reached
- D.
Not Tm limited
Correct Answer
A. Hormonally controlled in distal tubule segmentsExplanation
Electrolyte reabsorption in the renal tubules is primarily controlled by hormones in the distal tubule segments. This means that the reabsorption of electrolytes such as sodium, potassium, and calcium is regulated by hormones like aldosterone and antidiuretic hormone (ADH) in these specific regions of the tubules. The distal tubule is responsible for fine-tuning the reabsorption and excretion of electrolytes, under the influence of hormonal signals. This ensures that electrolyte balance is maintained in the body by adjusting the amount of reabsorption based on the body's needs.Rate this question:
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- 24.
The macula densa cells respond to ________.
- A.
Changes in solute content of the filtrate
- B.
Antidiuretic hormone
- C.
Changes in pressure in the tubule
- D.
Aldosterone
Correct Answer
A. Changes in solute content of the filtrateExplanation
The macula densa cells are specialized cells located in the kidney that monitor the solute content of the filtrate. They respond to changes in the concentration of solutes in the filtrate by releasing chemical signals that regulate the function of the nearby juxtaglomerular cells. These juxtaglomerular cells then adjust the production and release of renin, a hormone that plays a crucial role in regulating blood pressure and fluid balance in the body. Therefore, the macula densa cells play a key role in maintaining homeostasis by responding to changes in solute content of the filtrate.Rate this question:
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- 25.
Which of the following is not reabsorbed by the proximal convoluted tubule?
- A.
K+
- B.
Glucose
- C.
Na+
- D.
Creatinine
Correct Answer
D. CreatinineExplanation
The proximal convoluted tubule is responsible for reabsorbing most of the filtered substances back into the bloodstream. However, creatinine is not reabsorbed by the proximal convoluted tubule and is instead excreted in the urine. This is because creatinine is a waste product of muscle metabolism and does not have any significant physiological function in the body. Therefore, it is not necessary for the body to reabsorb creatinine and it is eliminated through the urine.Rate this question:
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- 26.
The fluid in the glomerular (Bowman's) capsule is similar to plasma except that it does not contain a significant amount of ________.
- A.
Plasma protein
- B.
Glucose
- C.
Electrolytes
- D.
Hormones
Correct Answer
A. Plasma proteinExplanation
The fluid in the glomerular (Bowman's) capsule is similar to plasma in many ways, but it does not contain a significant amount of plasma protein. Plasma proteins, such as albumin and globulin, are large molecules that are usually too big to pass through the filtration barrier of the glomerulus. Therefore, they are not present in significant amounts in the fluid that is filtered into the glomerular capsule. Glucose, electrolytes, and hormones, on the other hand, are all present in the glomerular filtrate and can be reabsorbed by the renal tubules.Rate this question:
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- 27.
Alcohol acts as a diuretic because it ________.
- A.
Increases secretion of ADH
- B.
Inhibits the release of ADH
- C.
Is not reabsorbed by the tubule cells
- D.
Increases the rate of glomerular filtration
Correct Answer
B. Inhibits the release of ADHExplanation
Alcohol acts as a diuretic because it inhibits the release of ADH. ADH, or antidiuretic hormone, is responsible for regulating the amount of water reabsorbed by the kidneys. When alcohol is consumed, it suppresses the release of ADH, leading to increased urine production and a decrease in water reabsorption. This can result in dehydration and increased frequency of urination.Rate this question:
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- 28.
The function of angiotensin II is to ________.
- A.
Constrict arterioles and increase blood pressure
- B.
Decrease water absorption
- C.
Decrease arterial blood pressure
- D.
Decrease the production of aldosterone
Correct Answer
A. Constrict arterioles and increase blood pressureExplanation
Angiotensin II is a hormone that is released in response to low blood pressure or low blood volume. Its main function is to constrict arterioles, which are small blood vessels, causing them to narrow. This narrowing increases resistance to blood flow and ultimately increases blood pressure. Therefore, the correct answer is that angiotensin II constricts arterioles and increases blood pressure.Rate this question:
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- 29.
A disease caused by inadequate secretion of antidiuretic hormone (ADH) by the pituitary gland with symptoms of polyuria is ________.
- A.
Diabetes insipidus
- B.
Diabetic acidosis
- C.
Diabetes mellitus
- D.
Coma
Correct Answer
A. Diabetes insipidusExplanation
Diabetes insipidus is a disease caused by inadequate secretion of antidiuretic hormone (ADH) by the pituitary gland. This hormone helps regulate the amount of water reabsorbed by the kidneys, so when there is a deficiency of ADH, excessive amounts of dilute urine are produced, leading to symptoms of polyuria (excessive urination). Diabetic acidosis is a condition associated with high levels of ketones in the blood, diabetes mellitus is a chronic condition characterized by high blood sugar levels, and coma is a state of unconsciousness.Rate this question:
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- 30.
An important characteristic of urine is its specific gravity or density, which is ________.
- A.
1.000-1.015
- B.
1.041-1.073
- C.
1.001-1.035
- D.
1.030-1.040
Correct Answer
C. 1.001-1.035Explanation
Urine specific gravity or density refers to the concentration of solutes in urine. A specific gravity range of 1.001-1.035 is considered normal for urine. This range indicates that the urine is neither too dilute nor too concentrated, suggesting a healthy balance of water and solutes in the body.Rate this question:
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- 31.
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, 6, 2, 1, 5, 4
- B.
3, 1, 2, 6, 5, 4
- C.
3, 1, 2, 6, 5, 4
- D.
6, 3, 2, 1, 5, 4
Correct Answer
A. 3, 6, 2, 1, 5, 4Explanation
The correct sequence of the formation and elimination of a drop of urine from the body is as follows: First, the nephron filters the blood and produces urine. Then, the collecting duct carries the urine to the minor calyx. From the minor calyx, the urine moves to the major calyx. Next, it passes through the ureter, which transports it to the bladder. Finally, the urine is eliminated from the body through the urethra. Therefore, the correct answer is 3, 6, 2, 1, 5, 4.Rate this question:
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- 32.
Select the correct statement about the nephrons.
- A.
Podocytes are the branching epithelial cells that line the tubules of the nephron.
- B.
Filtration slits are the pores that give fenestrated capillaries their name.
- C.
The parietal layer of the glomerular capsule is simple squamous epithelium.
- D.
The glomerulus is correctly described as the proximal end of the proximal convoluted tubule.
Correct Answer
C. The parietal layer of the glomerular capsule is simple squamous epithelium.Explanation
The parietal layer of the glomerular capsule is simple squamous epithelium. This means that it is composed of a single layer of flat cells. This is important because the parietal layer of the glomerular capsule forms the outer wall of the capsule, while the inner wall is formed by the visceral layer, which consists of specialized cells called podocytes. The simple squamous epithelium of the parietal layer allows for the passive diffusion of substances into the capsule, while the podocytes help to regulate the filtration process by forming filtration slits.Rate this question:
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- 33.
What would happen if the capsular hydrostatic pressure were increased above normal?
- A.
Filtration would increase in proportion to the increase in capsular pressure.
- B.
Net filtration would decrease.
- C.
Net filtration would increase above normal.
- D.
Capsular osmotic pressure would compensate so that filtration would not change.
Correct Answer
B. Net filtration would decrease.Explanation
If the capsular hydrostatic pressure were increased above normal, it would create a greater force pushing fluid out of the glomerulus and into the Bowman's capsule. This increased pressure would lead to an increased rate of filtration. However, as the question asks about the overall effect, it is important to consider other factors. The increase in filtration would cause a greater loss of fluid and solutes, leading to a decrease in net filtration. Therefore, the correct answer is that net filtration would decrease.Rate this question:
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- 34.
Which of the following is not a part of the juxtaglomerular apparatus?
- A.
Granular cells
- B.
Mesangial cells
- C.
Podocyte cells
- D.
Macula densa
Correct Answer
C. Podocyte cellsExplanation
The juxtaglomerular apparatus is a structure located in the kidney that regulates blood pressure and filtration. It consists of granular cells, mesangial cells, and macula densa. Granular cells secrete the enzyme renin, which helps regulate blood pressure. Mesangial cells provide structural support to the glomerulus and help regulate blood flow. Macula densa cells are specialized cells in the distal tubule that monitor the concentration of sodium and chloride in the filtrate. Podocyte cells, on the other hand, are located in the glomerulus and play a role in filtration by forming a filtration barrier. Therefore, podocyte cells are not a part of the juxtaglomerular apparatus.Rate this question:
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- 35.
Tubular reabsorption ________.
- A.
By active mechanisms usually involves movement against an electrical and/or chemical gradient
- B.
Includes substances such as creatinine
- C.
By passive processes requires ATP to move solutes from the interior of the tubule to the blood
- D.
Is a way for the body to get rid of unwanted waste
Correct Answer
A. By active mechanisms usually involves movement against an electrical and/or chemical gradientExplanation
Tubular reabsorption refers to the process in which substances are reabsorbed from the renal tubules back into the bloodstream. This process is usually carried out by active mechanisms, meaning that energy is required. Additionally, the movement of substances during tubular reabsorption occurs against an electrical and/or chemical gradient, meaning that substances are being moved from an area of lower concentration to an area of higher concentration. This helps to ensure that necessary substances are retained in the body while waste products are eliminated.Rate this question:
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- 36.
Which of the following is not a reason why substances are either not reabsorbed or are incompletely reabsorbed from the nephron?
- A.
They are too large to pass through the fenestrations.
- B.
They are extremely complex molecules.
- C.
They are not lipid soluble.
- D.
They lack carriers.
Correct Answer
B. They are extremely complex molecules.Explanation
The reason why substances are either not reabsorbed or are incompletely reabsorbed from the nephron is not because they are extremely complex molecules. The other options provided are valid reasons for substances not being reabsorbed or being incompletely reabsorbed.Rate this question:
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- 37.
Reabsorption of high levels of glucose and amino acids in the filtrate is accomplished by ________.
- A.
Countertransport
- B.
Facilitated diffusion
- C.
Passive transport
- D.
Secondary active transport
Correct Answer
D. Secondary active transportExplanation
Secondary active transport is the correct answer because it involves the movement of molecules across a cell membrane using energy from an electrochemical gradient established by primary active transport. In this case, high levels of glucose and amino acids are reabsorbed from the filtrate against their concentration gradient, which requires energy. Therefore, secondary active transport is the process by which this reabsorption occurs.Rate this question:
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- 38.
Which of the choices below is a function of the loop of Henle?
- A.
Absorb electrolytes actively with an automatic absorption of water by osmosis
- B.
Form a large volume of very concentrated urine or a small volume of very dilute urine
- C.
Form a large volume of very dilute urine or a small volume of very concentrated urine
- D.
None of these
Correct Answer
C. Form a large volume of very dilute urine or a small volume of very concentrated urineExplanation
The loop of Henle is responsible for forming a large volume of very dilute urine or a small volume of very concentrated urine. This is achieved through the process of actively absorbing electrolytes and allowing for the automatic absorption of water by osmosis.Rate this question:
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- 39.
Fetal kidneys do not have to work very hard because ________.
- A.
The placenta allows the mother's urinary system to clear the waste from fetal blood
- B.
there are no functional nephrons until after birth
- C.
There is no way a fetus could excrete urine until the seventh month of development
- D.
Fetuses do not have any waste to excrete
Correct Answer
A. The placenta allows the mother's urinary system to clear the waste from fetal bloodExplanation
The correct answer is that the placenta allows the mother's urinary system to clear the waste from fetal blood. During pregnancy, the placenta acts as a filter, removing waste products from the fetal blood and transferring them to the mother's bloodstream for elimination through her urinary system. This allows the fetal kidneys to remain relatively inactive as the waste is processed by the mother's kidneys.Rate this question:
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- 40.
Which of the following best describes kidney function in older adults (70 years or older)?
- A.
Kidney function decreases due to kidney atrophy.
- B.
Only about 3% of older adults have any loss of kidney function.
- C.
Kidney function remains the same throughout life, regardless of age.
- D.
Only obese and diabetic older adults have any kidney dysfunction.
Correct Answer
A. Kidney function decreases due to kidney atrophy.Explanation
As individuals age, their kidney function tends to decrease due to kidney atrophy. This means that the kidneys shrink in size and lose some of their filtering capacity. This decline in kidney function can lead to a decrease in the ability to filter waste products from the blood and regulate fluid and electrolyte balance. It is a normal part of the aging process and can contribute to an increased risk of kidney disease and other related health issues in older adults.Rate this question:
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- 41.
The factor favoring filtrate formation at the glomerulus is the ________.
- A.
Glomerular hydrostatic pressure
- B.
Capsular hydrostatic pressure
- C.
Myogenic mechanism
- D.
Colloid osmotic pressure of the blood
Correct Answer
A. Glomerular hydrostatic pressureExplanation
The factor favoring filtrate formation at the glomerulus is the glomerular hydrostatic pressure. This pressure is created by the force of blood pushing against the walls of the glomerular capillaries. It is responsible for forcing water and small solutes out of the blood and into the glomerular capsule to form the initial filtrate. Capsular hydrostatic pressure, myogenic mechanism, and colloid osmotic pressure of the blood are not directly involved in the formation of the filtrate at the glomerulus.Rate this question:
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- 42.
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 reabsorbed by secondary active transport
- B.
Be actively secreted into the filtrate
- C.
Appear in the urine
- D.
Be completely reabsorbed by the tubule cells
Correct Answer
C. Appear in the urineExplanation
The Tm (transport maximum) is the maximum rate at which a substance can be reabsorbed by the renal tubules. If the concentration of a substance in the blood exceeds the Tm, the excess amount will not be reabsorbed and will instead appear in the urine. In this case, the concentration of the amino acid (230 mg/100 ml) exceeds its Tm (120 mg/100 ml), indicating that it will be excreted in the urine.Rate this question:
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- 43.
If one says that the clearance value of glucose is zero, what does this mean?
- A.
Most of the glucose is filtered out of the blood and is not reabsorbed in the convoluted tubules.
- B.
The glucose molecule is too large to be filtered out of the blood.
- C.
Normally all the glucose is reabsorbed.
- D.
The clearance value of glucose is relatively high in a healthy adult.
Correct Answer
C. Normally all the glucose is reabsorbed.Explanation
If one says that the clearance value of glucose is zero, it means that normally all the glucose is reabsorbed. This implies that none of the filtered glucose is excreted in the urine, as it is efficiently reabsorbed by the convoluted tubules in the kidneys.Rate this question:
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- 44.
Excretion of dilute urine requires ________.
- A.
The presence of ADH
- B.
The presence of ADH
- C.
Relative permeability of the distal tubule to water
- D.
Transport of sodium and chloride ions out of the descending loop of Henle
Correct Answer
B. The presence of ADHExplanation
The correct answer is the presence of ADH. ADH, or antidiuretic hormone, is responsible for regulating the amount of water reabsorbed by the kidneys. When ADH is present, the kidneys reabsorb more water, resulting in the production of concentrated urine. However, when ADH is absent or low, the kidneys excrete more water, resulting in the production of dilute urine. Therefore, the presence of ADH is necessary for the excretion of dilute urine.Rate this question:
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- 45.
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 secreting sodium ions
- C.
By producing new bicarbonate ions
- D.
By reabsorbing filtered bicarbonate ions
Correct Answer
B. By secreting sodium ionsExplanation
The cells of the renal tubules can raise blood pH by secreting hydrogen ions into the filtrate, by producing new bicarbonate ions, and by reabsorbing filtered bicarbonate ions. However, secreting sodium ions does not directly contribute to raising blood pH. Sodium ions are involved in the reabsorption process but do not directly affect blood pH levels.Rate this question:
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- 46.
In the ascending limb of the loop of Henle the ________.
- A.
Thin segment is freely permeable to water
- B.
Thick segment is permeable to water
- C.
Thick segment moves ions out into interstitial spaces for reabsorption
- D.
Thin segment is not permeable to sodium and chloride
Correct Answer
C. Thick segment moves ions out into interstitial spaces for reabsorptionExplanation
The correct answer is that in the ascending limb of the loop of Henle, the thick segment moves ions out into interstitial spaces for reabsorption. This is because the ascending limb of the loop of Henle is impermeable to water, but actively transports ions such as sodium and chloride out of the tubular fluid and into the interstitial spaces. This creates a concentration gradient that allows for the reabsorption of water in the descending limb of the loop of Henle.Rate this question:
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- 47.
Select the correct statement about urinary system development.
- A.
The metanephric ducts will become the urethras.
- B.
The mesonephros will develop into the kidneys.
- C.
Kidneys develop from urogenital ridges.
- D.
The pronephros (first tubule system) develops during the tenth week of gestation.
Correct Answer
C. Kidneys develop from urogenital ridges.Explanation
The correct statement is that kidneys develop from urogenital ridges. During embryonic development, the urogenital ridges give rise to the kidneys. The kidneys develop from the intermediate mesoderm and undergo a complex process of differentiation and morphogenesis to form the functional organs. The metanephric ducts, on the other hand, give rise to the ureters, not the urethras. The mesonephros is a temporary kidney structure that is replaced by the metanephros during development. The pronephros is the first tubule system to develop, but it occurs earlier in gestation, not during the tenth week.Rate this question:
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- 48.
Which of the choices below does not describe the importance of tubular secretion?
- A.
Ridding the body of excessive potassium ions
- B.
Ridding the body of bicarbonate ions
- C.
Eliminating undesirable substances such as urea and uric acid that have been reabsorbed by passive processes
- D.
Disposing of substances not already in the filtrate, such as certain drugs
Correct Answer
B. Ridding the body of bicarbonate ionsExplanation
Tubular secretion is the process in which substances are actively transported from the blood into the renal tubules for excretion. It plays a crucial role in maintaining electrolyte balance and pH regulation. The options given describe the importance of tubular secretion, except for "ridding the body of bicarbonate ions." Bicarbonate ions are important in maintaining the body's acid-base balance, and they are primarily reabsorbed rather than secreted in the renal tubules. Therefore, the correct answer is "ridding the body of bicarbonate ions."Rate this question:
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- 49.
Which statement is correct?
- A.
Most of the water passing through the kidney is eliminated as urine.
- B.
Reabsorption of water is hormonally controlled.
- C.
The excretion of sodium ions is one of the mechanisms that maintains the pH balance of the blood.
- D.
Normal filtrate contains a large amount of protein.
Correct Answer
B. Reabsorption of water is hormonally controlled.Explanation
The statement that is correct is that reabsorption of water is hormonally controlled. This means that the amount of water that is reabsorbed by the kidney and returned to the bloodstream is regulated by hormones. Hormones such as antidiuretic hormone (ADH) and aldosterone play a role in controlling the reabsorption of water in the kidney tubules. These hormones signal the kidneys to either retain water or excrete it, depending on the body's hydration needs.Rate this question:
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- 50.
What is the function of the juxtaglomerular apparatus?
- A.
Help regulate blood pressure and the rate of excretion by the kidneys
- B.
Help regulate water and electrolyte excretion by the kidneys
- C.
Help regulate urea absorption by the kidneys
- D.
Help regulate blood pressure and the rate of blood filtration by the kidneys
Correct Answer
D. Help regulate blood pressure and the rate of blood filtration by the kidneysExplanation
The juxtaglomerular apparatus is responsible for regulating blood pressure and the rate of blood filtration by the kidneys. It consists of specialized cells located near the glomerulus in the kidney. These cells monitor the blood pressure and release hormones, such as renin, in response to changes in blood pressure. Renin helps regulate blood pressure by initiating the production of angiotensin II, a hormone that constricts blood vessels and increases blood volume. This mechanism helps maintain a stable blood pressure and controls the rate of blood filtration in the kidneys.Rate this question:
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Mar 21, 2023Quiz Edited by
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Mar 02, 2011Quiz Created by
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