Anatomy and Phys II Exam 4 Urinary System
Access The Exact Questions for Anatomy and Phys II Exam 4 Urinary System
💯 100% Pass Rate guaranteed
🗓️ Unlock for 1 Month
Rated 4.8/5 from over 1000+ reviews
- Unlimited Exact Practice Test Questions
- Trusted By 200 Million Students and Professors
What’s Included:
- Unlock Actual Exam Questions and Answers for Anatomy and Phys II Exam 4 Urinary System on monthly basis
- Well-structured questions covering all topics, accompanied by organized images.
- Learn from mistakes with detailed answer explanations.
- Easy To understand explanations for all students.
Ace Your Test with Anatomy and Phys II Exam 4 Urinary System Actual Questions and Solutions - Full Set
Free Anatomy and Phys II Exam 4 Urinary System Questions
The kidneys are stimulated to produce renin _______.
-
When the specific gravity of urine rises above 1.10
-
When the pH of the urine decreases
-
When the peritubular capillaries are dilated
-
By a decrease in the blood pressure
Explanation
Explanation:
Correct Answer: (D) By a decrease in the blood pressure
Renin is produced and released by the granular cells of the juxtaglomerular apparatus in response to a decrease in blood pressure (or decreased stretch of the afferent arteriole), decreased NaCl delivery to the macula densa, or sympathetic nervous system stimulation. Renin initiates the renin-angiotensin-aldosterone system (RAAS) to restore blood pressure back to normal.
Why Other Options are Incorrect:
- A. When the specific gravity of urine rises above 1.10 — Urine specific gravity reflects urine concentration and is not a direct trigger for renin release by the kidneys.
- B. When the pH of the urine decreases — Urine pH changes do not directly stimulate renin production; renin release is triggered by pressure and NaCl concentration changes.
- C. When the peritubular capillaries are dilated — Dilation of peritubular capillaries is not a recognized stimulus for renin release; it is the afferent arteriole pressure that the granular cells monitor.
The macula densa cells respond to _______.
-
Changes in NaCl concentration of the filtrate
-
Antidiuretic hormone
-
Aldosterone
-
Changes in pressure in the tubule
Explanation
Explanation:
Correct Answer: (A) Changes in NaCl concentration of the filtrate
The macula densa cells are specialized chemoreceptors located in the distal convoluted tubule that detect changes in the sodium chloride (NaCl) concentration of the filtrate passing through the tubule. When NaCl concentration falls, the macula densa signals the granular cells to release renin, initiating the RAAS cascade to restore blood pressure and filtration rate.
Why Other Options are Incorrect:
- B. Antidiuretic hormone — ADH acts on the collecting duct to increase water permeability, not on the macula densa cells.
- C. Aldosterone — Aldosterone acts on the principal cells of the collecting duct to promote sodium reabsorption, not on the macula densa cells.
- D. Changes in pressure in the tubule — Tubular pressure is monitored by the granular cells of the juxtaglomerular apparatus, not specifically by the macula densa cells.
The presence of protein in the urine indicates which of the following?
-
Damage to the filtration membrane
-
High levels of transcription and translation by the body's tissues
-
Damage to the renal tubules
-
Too much protein in the diet
Explanation
Explanation:
Correct Answer: (A) Damage to the filtration membrane
Protein molecules, particularly albumin, are normally too large to pass through the intact glomerular filtration membrane. The presence of significant protein in the urine (proteinuria) indicates that the filtration membrane has been damaged, allowing proteins to leak through into the filtrate. This is a hallmark sign of glomerular diseases such as glomerulonephritis and nephrotic syndrome.
Why Other Options are Incorrect:
- B. High levels of transcription and translation by the body's tissues — Protein synthesis activity in body tissues does not directly cause protein to appear in urine; it is the integrity of the filtration membrane that determines protein loss.
- C. Damage to the renal tubules — Tubular damage would affect reabsorption and secretion of small molecules, not typically result in significant proteinuria, as protein filtration is primarily controlled at the glomerular level.
- D. Too much protein in the diet — Dietary protein intake does not directly cause proteinuria; the kidneys efficiently handle normal variations in dietary protein without allowing protein into the urine.
An increase in the permeability of the cells of the collecting duct to water is due to a(n) _______.
-
Increase in the production of aldosterone
-
Decrease in the production of ADH
-
Decrease in the concentration of the blood plasma
-
Increase in the production of ADH
Explanation
Explanation:
Correct Answer: (D) Increase in the production of ADH
Antidiuretic hormone (ADH), also known as vasopressin, is responsible for increasing the permeability of the collecting duct cells to water. When ADH is released from the posterior pituitary gland, it binds to receptors on collecting duct cells, triggering the insertion of aquaporin channels into the cell membranes. This allows water to be reabsorbed from the filtrate back into the bloodstream, concentrating the urine.
Why Other Options are Incorrect:
- A. Increase in the production of aldosterone — Aldosterone acts on the collecting duct to increase sodium reabsorption and potassium excretion, not to increase water permeability directly.
- B. Decrease in the production of ADH — A decrease in ADH would reduce water permeability of the collecting duct, resulting in more dilute urine and increased urine output.
- C. Decrease in the concentration of the blood plasma — A decrease in blood plasma concentration would actually suppress ADH release, reducing water reabsorption rather than increasing it.
Excretion of dilute urine requires _______.
-
Transport of sodium and chloride ions out of the descending nephron loop
-
The presence of ADH
-
Relative permeability of the distal convoluted tubule to water
-
Impermeability of the collecting duct to water
Explanation
Explanation:
Correct Answer: (D) Impermeability of the collecting duct to water
For dilute urine to be produced, water must NOT be reabsorbed in the collecting duct. When ADH is absent or low, the collecting duct remains impermeable to water, allowing the dilute filtrate to pass through and be excreted as dilute urine. This occurs when the body is well hydrated and does not need to conserve water.
Why Other Options are Incorrect:
- A. Transport of sodium and chloride ions out of the descending nephron loop — Sodium and chloride are actively transported out of the ascending limb, not the descending limb. This process helps establish the medullary gradient for concentrated, not dilute, urine production.
- B. The presence of ADH — ADH increases collecting duct permeability to water, promoting water reabsorption and concentrated urine production — the opposite of what is needed for dilute urine.
- C. Relative permeability of the distal convoluted tubule to water — For dilute urine, the tubule and collecting duct need to be impermeable to water, not permeable.
The thin segment of the loop of Henle descending limb _______.
-
Aids in the passive movement of water out of the tubule
-
Is easily broken and replaced often
-
Aids in the passive excretion of nitrogenous waste
-
Helps to pack a greater number of nephron loops into a smaller space
Explanation
Explanation:
Correct Answer: (A) Aids in the passive movement of water out of the tubule
The thin descending limb of the loop of Henle is highly permeable to water. As the tubular fluid descends into the increasingly hypertonic medullary interstitium, water moves passively out of the tubule by osmosis. This passive water movement concentrates the tubular fluid and is a critical step in the countercurrent multiplication system that establishes the medullary osmotic gradient.
Why Other Options are Incorrect:
- B. Is easily broken and replaced often — This is not a recognized physiological characteristic of the thin descending limb; renal tubule cells are not described in terms of being easily broken and replaced.
- C. Aids in the passive excretion of nitrogenous waste — Urea recycling occurs primarily in the inner medullary collecting duct, not in the thin descending limb.
- D. Helps to pack a greater number of nephron loops into a smaller space — While the thin segment does allow for a longer loop in a compact space, this is a structural feature, not a functional description, and is not the best answer.
The fluid in glomerular capsule is similar to plasma except that it does NOT contain a significant amount of _______.
-
Plasma protein
-
Glucose
-
Electrolytes
-
Hormones
Explanation
Explanation:
Correct Answer: (A) Plasma protein
The glomerular filtrate (fluid in Bowman's capsule) is essentially a protein-free filtrate of plasma. The glomerular filtration membrane acts as a selective barrier that prevents large molecules such as plasma proteins (albumin, globulins) from passing into the filtrate due to their large size and negative charge. The presence of significant protein in the urine (proteinuria) is therefore a sign of glomerular damage.
Why Other Options are Incorrect:
- B. Glucose — Glucose is a small molecule that freely passes through the glomerular filtration membrane and is present in the filtrate; it is normally completely reabsorbed in the proximal convoluted tubule.
- C. Electrolytes — Electrolytes such as sodium, potassium, and chloride freely filter through the glomerulus and are present in the filtrate.
- D. Hormones — Small hormones and other small molecules can pass through the glomerular filter and are present in the filtrate.
What is the effect of antidiuretic hormone on the cells of the collecting duct?
-
Triggers synthesis of more sodium channels in the collecting duct apical membranes
-
Triggers synthesis of more potassium channels in the collecting duct apical membranes
-
Causes aquaporins to be inserted into the collecting duct apical membranes
-
Inhibits sodium reabsorption through the collecting duct apical membranes
Explanation
Explanation:
Correct Answer: (C) Causes aquaporins to be inserted into the collecting duct apical membranes
ADH (antidiuretic hormone/vasopressin) binds to V2 receptors on collecting duct cells, triggering a cAMP-mediated signaling cascade that causes aquaporin-2 water channels to be inserted into the apical membranes of the collecting duct cells. This dramatically increases the permeability of the collecting duct to water, allowing water to be reabsorbed by osmosis into the hypertonic medullary interstitium, producing concentrated urine.
Why Other Options are Incorrect:
- A. Triggers synthesis of more sodium channels — Sodium channel regulation in the collecting duct is primarily controlled by aldosterone, not ADH.
- B. Triggers synthesis of more potassium channels — Potassium channel regulation is associated with aldosterone's effects on principal cells, not ADH.
- D. Inhibits sodium reabsorption — ADH does not inhibit sodium reabsorption; its primary action is on water permeability through aquaporin insertion.
What is the best explanation for the microvilli on the apical surface of the proximal convoluted tubule (PCT)?
-
They increase the amount of surface area that comes in contact with the blood's plasma to help actively excrete toxins
-
They hold on to enzymes that cleanse the filtrate before reabsorption
-
Their movements propel the filtrate through the tubules
-
They increase the surface area and allow for a greater number of solute molecules to be reabsorbed
Explanation
Explanation:
Correct Answer: (D) They increase the surface area and allow for a greater number of solute molecules to be reabsorbed
The microvilli on the apical surface of the PCT cells form the brush border, which dramatically increases the surface area available for reabsorption. The PCT is responsible for reabsorbing approximately 65% of the filtered water, sodium, glucose, amino acids, and other valuable solutes. The increased surface area provided by the microvilli maximizes the efficiency of this reabsorption process.
Why Other Options are Incorrect:
- A. They increase surface area that comes in contact with blood's plasma to actively excrete toxins — Microvilli face the tubular lumen, not the blood's plasma. Their primary role is reabsorption, not toxin excretion.
- B. They hold on to enzymes that cleanse the filtrate before reabsorption — While the brush border does contain some enzymes, the primary and best explanation for the microvilli is the dramatic increase in reabsorptive surface area.
- C. Their movements propel the filtrate through the tubules — Microvilli are non-motile projections; they do not move or propel filtrate. Peristalsis and hydrostatic pressure gradients move filtrate through the tubules.
If the diameter of the efferent arterioles leading away from the glomerulus increases (vasodilation), which of the following is NOT likely to occur?
-
Systemic blood pressure will decrease
-
Glomerular filtration rate will decrease
-
Net filtration pressure will decrease
-
Urine output will decrease
Explanation
Explanation:
Correct Answer: (A) Systemic blood pressure will decrease
When the efferent arteriole vasodilates, blood drains away from the glomerulus more easily, which reduces glomerular hydrostatic pressure. This leads to decreased net filtration pressure, decreased GFR, and decreased urine output. However, systemic blood pressure decreasing is NOT a direct or expected consequence of efferent arteriole vasodilation alone — efferent dilation primarily affects glomerular dynamics locally, not systemic blood pressure directly.
Why Other Options are Incorrect (i.e., these WOULD likely occur):
- B. Glomerular filtration rate will decrease — TRUE; with easier outflow through the dilated efferent arteriole, glomerular hydrostatic pressure drops, reducing GFR.
- C. Net filtration pressure will decrease — TRUE; reduced glomerular hydrostatic pressure means less driving force for filtration, lowering net filtration pressure.
- D. Urine output will decrease — TRUE; a lower GFR means less filtrate is produced, resulting in decreased urine output.
How to Order
Select Your Exam
Click on your desired exam to open its dedicated page with resources like practice questions, flashcards, and study guides.Choose what to focus on, Your selected exam is saved for quick access Once you log in.
Subscribe
Hit the Subscribe button on the platform. With your subscription, you will enjoy unlimited access to all practice questions and resources for a full 1-month period. After the month has elapsed, you can choose to resubscribe to continue benefiting from our comprehensive exam preparation tools and resources.
Pay and unlock the practice Questions
Once your payment is processed, you’ll immediately unlock access to all practice questions tailored to your selected exam for 1 month .