OAT Biology - Problem Drill 16: The Urinary System Question No. 1 of 10 1. Which of the following would solve a drop in blood ph? Question #01 (A) Decreased retention of acids. (B) Increased excretion of bases. (C) Increased excretion of water. (D) Increased retention of acids. (E) Increased retention of water. A. Correct! Flushing acids from the system will assist in re-establishing the acid-base equilibrium in the blood. Removing bases from the blood will only further upset the imbalance in blood ph. Increased excretion of water will not solve the problem. Keeping acids in the system will only serve to maintain the low ph. Increased retention of water will not solve the problem. Acids and bases are types of electrolytes, or molecules that carry electric charge. The regulation of electrolyte excretion by the kidney is one way that the urinary system functions in homeostasis (i.e., the maintenance of a stable internal environment). Under normal circumstances, blood ph is maintained around ph 7.4. The correct answer is (A).
Question No. 2 of 10 2. Which of the following would be cause for concern if detected in urine? Question #02 (A) Peptides. (B) NaCl. (C) Red blood cells. (D) Uric acid. (E) Water While large proteins are not expected to be found in urine, small peptides or amino acids would not cause concern. Salt is not an unexpected component of urine. C. Correct! Red blood cells are not a normal feature of glomerular filtrate. Uric acid is a normal byproduct of protein catabolism, and would be expected to be included in urine. Water is an expected part of urine. Urine formation allows for the excretion of waste products, such as the nitrogenous compounds urea and uric acid. The process of blood filtration, which occurs in Bowman s capsule through the glomerulus, creates a filtrate that is passed through the renal tubule. This filtrate contains water, nutrients, and salts. Most of these components are reabsorbed, and the remaining compounds are excreted as urine. The filtration process is selective, however, with the glomerulus acting like a sieve to allow small molecules through (e.g., salts or amino acids) while excluding large items (e.g., large proteins or cells). The correct answer is (C).
Question No. 3 of 10 3. What is the correct sequence of events in the nephron? Question #03 I. Loop of Henle II. Collecting Duct III. Proximal Tubule IV. Glomerulus (A) II, I, III, IV (B) II, IV, III, I (C) IV, III, I, II (D) III, IV, I, II (E) IV, III, II, I The sequence of events starts with Glomerulus and ends with Collecting Duct. The sequence of events starts with Glomerulus and ends with Collecting Duct. C. Correct! The sequence of events starts with Glomerulus and ends with Collecting Duct. The sequence of events starts with Glomerulus and ends with Collecting Duct. The sequence of events starts with Glomerulus and ends with Collecting Duct. The events within the nephron (which includes filtration and reabsorption) occur as follows: 1. Glomerulus 2. Proximal tubule 3. Loop of Henle 4. Distal tubule 5. Collecting duct The correct answer is (C).
Question No. 4 of 10 4. What is the main difference in the glomerular filtrate of the proximal and distal tubules? Question #04 (A) The fluid in the proximal tubule has more volume than fluid in the distal tubule. (B) There is less protein in the fluid of the distal tubule than in the fluid of the proximal tubule. (C) The sodium concentration will be higher in the proximal tubule than in the distal tubule. (D) The glucose concentration will be lower in the distal tubule than in the proximal tubule. (E) The fluid in the proximal tubule has less volume than fluid in the distal tubule. A. Correct! A significant reduction in filtrate volume occurs through the loop of Henle. Large items, such as proteins and cells, are normally excluded from the glomerular filtrate. The solute concentration of the fluid in the renal tubule is largely unchanged by the loop of Henle. The solute concentration of the fluid in the renal tubule is largely unchanged by the loop of Henle. The fluid in the proximal tubule has more volume than fluid in the distal tubule. Glomerular filtrate passing from the proximal to the distal tubule must go through the loop of Henle. The function of the loop of Henle is to reduce the overall volume of the filtrate. The concentrations of the solutes in the renal tubule fluid change little during this process. The correct answer is (A).
Question No. 5 of 10 5. Which of the following would result in more concentrated urine? Question #05 (A) Impaired function of the proximal tubule. (B) Increased anti-diuretic hormone level. (C) The loop of Henle. (D) Decreased anti-diuretic hormone level. (E) Constant anti-diuretic hormone level. The proximal portion of the renal tubule is where most of the glomerular filtrate is reabsorbed. If its function is impaired, fewer solutes and water would be retained, which would produce more dilute urine. B. Correct! Increased anti-diuretic hormone will create more concentrated urine. The loop of Henle reduces the overall volume of the glomerular filtrate, without having much effect on its solute concentration. Decreased anti-diuretic hormone levels will not result in more concentrated urine. Increased anti-diuretic hormone will create more concentrated urine. Anti-diuretic hormone acts on the distal portion of the renal tubule to increase its permeability to water. As a result, more water is reabsorbed into the interstitial fluid and less is left in the renal tubule to be excreted as urine. The correct answer is (B).
Question No. 6 of 10 6. Which of the following is true regarding Bowman s capsule? Question #06 (A) Bowman s capsule is continuous with the collecting duct. (B) Bowman s capsule acts like a sieve to produce the glomerular filtrate. (C) Negative pressure within Bowman s capsule pulls fluid and solutes out of the glomerulus. (D) The walls of the glomerulus link directly into the proximal tubule. (E) Bowman s capsule is not continuous with the collecting duct. A. Correct! Bowman s capsule is continuous with the proximal renal tubule, the loop of Henle, the distal renal tubule, and finally, with the collecting duct. The glomerulus acts like a sieve, which allows small solutes and water to pass into Bowman s capsule as glomerular filtrate while restricting the entrance of large items like cells and large proteins. The glomerulus is a site of high pressure blood flow, whereby fluid and solutes are pushed out of the circulation and into the space of Bowman s capsule. The glomerulus is not continuous with the proximal tubule, but the Bowman s capsule is. Quite opposite, Bowman s capsule is continuous with the proximal renal tubule, the loop of Henle, the distal renal tubule, and finally, with the collecting duct. Each nephron has a Bowman s capsule, which encloses the glomerulus and opens directly into the proximal portion of the renal tubule. Blood enters the glomerulus through the afferent arteriole. The efferent arteriole has a smaller diameter than the afferent arteriole. This size difference creates pressure within the glomerulus. In addition, the cells that form the walls of the glomerular capillaries have small spaces that allow some of the high-pressure fluid to escape into Bowman s capsule and enter the renal tubule. The spaces, however, are not large enough to allow such things as cells or large proteins to escape from the circulation. The correct answer is (A).
Question No. 7 of 10 7. Which of the following is not a function of the urinary system? Question #07 (A) Osmoregulation. (B) Regulation of blood ph. (C) Waste excretion. (D) Thermoregulation. (E) Homeostasis Osmoregulation refers to the maintenance of equilibrium between water and solutes within an organism. The urinary system is intimately connected with this process through the function of the kidneys. The urinary system is involved in the regulation of blood ph, since excess electrolytes may be included in the urine and excreted. The urinary system produces, stores, and eliminates urine, which allows the body to rid itself of metabolic wastes. D. Correct! Thermoregulation is the process by which organisms keep their internal temperatures within certain boundaries. It is a major function of skin, but not the urinary system. The urinary system aids in homeostasis by functioning in blood ph regulation, acid/base regulation, osmoregulation, and excretion. Homeostasis is the maintenance of a stable internal environment within an organism. The urinary system aids in homeostasis by functioning in blood ph regulation, acid/base regulation, osmoregulation, and excretion. The correct answer is (D).
Question No. 8 of 10 8. Renal failure results in decreased glomerular filtration. Which of the following events would not be expected? Question #08 (A) Decreased urine production. (B) Disruption of blood ph. (C) Elevation of blood urea levels. (D) Dehydration. (E) Excess water. Decreased glomerular filtration would be expected to produce decreased urine production. An upset in excretion would be expected to produce an imbalance in electrolyte levels, including acids and bases. Urea, a nitrogenous waste product that is normally remove from the blood by the kidneys, would be expected to accumulate in the blood of patients with renal failure. D. Correct! Fluid retention during renal failure would not promote dehydration. When the kidneys cannot function normally, waste products and excess water accumulate throughout the body. Urinary system function is essential for osmoregulation, blood ph regulation, blood pressure regulation, and excretion. Urinary system dysfunction drastically alters the ability to maintain homeostasis. The correct answer is (D).
Question No. 9 of 10 9. Which of the following accurately describes the structure of the kidneys? Question #09 (A) There is one collecting duct in each kidney. (B) The medulla is the outer portion of the kidneys. (C) The renal artery enters the kidney at the hilum. (D) The kidney is attached directly to the bladder. (E) The ureters are not directly connected with the kidneys. There are several collecting ducts within each kidney, and each collecting duct accepts urine from multiple nephrons for ultimate delivery to the ureter. The regions of the kidney (from outside to inside) are the cortex, medulla, and pelvis. C. Correct! The entry point into each kidney, whereby the renal artery delivers the blood to be filtered in the glomeruli, is at the hilum. The kidneys are continuous with the bladder via the ureters, which deliver the urine for storage. The kidneys are continuous with the bladder via the ureters, which deliver the urine for storage. Keep in mind that the urinary system includes two kidneys, which are bean-shaped organs located behind the stomach. Each kidney is comprised of roughly one million nephrons. The correct answer is (C).
Question No. 10 of 10 10. What is the correct sequence of passage through the urinary system? Question #10 (A) Renal artery, kidneys, ureters, bladder, urethra. (B) Kidneys, ureters, bladder, urethra. (C) Kidneys, collecting ducts, ureters, urethra. (D) Kidneys, urethra, bladder, ureters. (E) Kidneys, bladder, ureters, urethra. Though it delivers blood to the kidney, the renal artery is part of the circulatory system, not the urinary system. B. Correct! This represents the correct sequence of passage through the urinary system. The collecting ducts are part of the kidneys. Ureters and urethra are out of order. The kidneys produce urine, the ureters transport it to the bladder for storage, and the urethra is the conduit for elimination of urine from the body. The urinary system is comprised of two kidneys, two ureters, one bladder, and one urethra. The kidneys produce urine, the ureters transport it to the bladder for storage, and the urethra is the conduit for elimination of urine from the body. The correct answer is (B).