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100 questions in this collection · Page 8 of 10
Question 71 of 100
📘 CLASS XI
Excretory Products And Their Elimination
Read the following statements about the role of saliva in excretion:
I. Saliva is primarily a digestive fluid but can act as an auxiliary excretory pathway. II. Small amounts of nitrogenous wastes can be excreted through saliva. III. Saliva is the main organ for regulating plasma urea levels in ureotelic animals. IV. Heavy metals and certain drugs can also be excreted in saliva.
Which statements are correct?
Statement I is correct because saliva primarily functions in digestion but also serves as a minor excretory route. Statement II is correct because small quantities of nitrogenous wastes such as urea are excreted through saliva. Statement III is incorrect because kidneys are the principal organs regulating plasma urea levels. Statement IV is correct because trace amounts of heavy metals and certain drugs may also be excreted through saliva.
Question 72 of 100
📘 CLASS XI
Excretory Products And Their Elimination
Evaluate the statements below regarding the pathophysiology of glomerulonephritis:
I. It is an autoimmune or infectious inflammatory condition of the renal tubules. II. It represents the inflammation of the glomeruli of the kidney. III. It can lead to blood (hematuria) and large proteins (proteinuria) leaking into the urine. IV. It has absolutely no effect on the overall glomerular filtration rate (GFR).
Select the correct option.
Statement I is incorrect because glomerulonephritis primarily affects the glomeruli rather than the renal tubules. Statement II is correct because it is inflammation of the glomeruli. Statement III is correct because damage to the filtration membrane permits red blood cells and proteins to enter the urine. Statement IV is incorrect because glomerulonephritis commonly reduces the glomerular filtration rate (GFR).
Question 73 of 100
📘 CLASS XI
Excretory Products And Their Elimination
Study the anatomical organization of the Malpighian corpuscle:
I. The Malpighian corpuscle is also known as the renal corpuscle. II. It consists of the glomerulus and Bowman's capsule. III. It is situated exclusively in the renal medulla. IV. It is the site where the initial step of urine formation (ultrafiltration) occurs.
Identify the correct statements.
Statement I is correct because the Malpighian corpuscle is another name for the renal corpuscle. Statement II is correct because it consists of the glomerulus enclosed by Bowman's capsule. Statement III is incorrect because all renal corpuscles are located in the renal cortex. Statement IV is correct because ultrafiltration begins in the renal corpuscle.
Question 74 of 100
📘 CLASS XI
Excretory Products And Their Elimination
Consider these statements about the transport properties of the collecting duct:
I. It is completely impermeable to water under all physiological conditions. II. It allows passage of small amounts of urea into the medullary interstitium to maintain its high osmolarity. III. It is a long, straight tube that carries urine from the cortex to the renal pelvis. IV. It can selectively secrete hydrogen (H+) and potassium (K+) ions to maintain blood pH.
Which statements are true?
Statement I is incorrect because the collecting duct becomes highly permeable to water in the presence of ADH. Statements II, III and IV are correct because the collecting duct participates in urea recycling, carries urine from cortex through the medulla, and secretes H+ and K+ ions to maintain acid-base and ionic balance.
Question 75 of 100
📘 CLASS XI
Excretory Products And Their Elimination
Read the following statements about uremia and its physiological impact:
I. Uremia is characterized by the accumulation of excess urea in the blood. II. It is primarily caused by hyperactive liver enzymes synthesizing too much urea. III. It is a clear clinical indicator of severe kidney malfunction. IV. If left untreated, uremia can lead to multi-organ failure and death.
Select the correct option.
Statement I is correct because uremia is the accumulation of urea in the blood. Statement II is incorrect because uremia results from kidney failure to excrete urea rather than excessive liver production. Statements III and IV are correct because uremia indicates severe renal dysfunction and may become fatal if untreated.
Question 76 of 100
📘 CLASS XI
Excretory Products And Their Elimination
Analyze the statements below regarding nitrogenous waste excretion across different habitats:
I. Aquatic reptiles and terrestrial insects are typically ammonotelic because ammonia is highly soluble in water. II. Terrestrial adaptation in animals necessitated the evolution of less toxic wastes to prevent excessive dehydration. III. Bony fishes excrete ammonium ions primarily across their body or gill surfaces via simple diffusion. IV. Mammals, terrestrial amphibians, and marine fishes are categorized as ureotelic organisms.
Statement I is incorrect because terrestrial insects are uricotelic, not ammonotelic. Statement II is correct because terrestrial adaptation favored less toxic nitrogenous wastes such as urea and uric acid to conserve water. Statement III is correct because bony fishes excrete ammonia mainly through the gills/body surface. Statement IV is correct because mammals, terrestrial amphibians and marine fishes are ureotelic.
Question 77 of 100
📘 CLASS XI
Excretory Products And Their Elimination
Study the following statements regarding the structural parts of the nephron and their locations:
I. The renal corpuscle (Malpighian corpuscle), PCT, and DCT are located in the cortical region of the kidney. II. The loop of Henle dips into the inner and outer medullary regions. III. Cortical nephrons possess highly elongated Henle's loops that extend extremely deep into the medulla. IV. The collecting ducts converge and open into the renal pelvis through the medullary pyramids.
Statements I, II and IV are correct. Statement III is incorrect because cortical nephrons possess short loops of Henle, whereas juxtamedullary nephrons have long loops extending deep into the medulla.
Question 78 of 100
📘 CLASS XI
Excretory Products And Their Elimination
Evaluate these statements about the transport characteristics of the Henle's loop descending limb:
I. It is highly permeable to water, allowing osmotic water removal to occur readily. II. It is almost entirely impermeable to electrolytes. III. Due to water outflow, the osmotic concentration of the remaining tubular fluid increases as it moves downward. IV. Active transport of sodium and potassium occurs abundantly in this descending portion.
Statements I, II and III are correct. Statement IV is incorrect because active transport of electrolytes occurs in the ascending limb, not in the descending limb.
Question 79 of 100
📘 CLASS XI
Excretory Products And Their Elimination
Analyze the statements below regarding the mechanics of the counter current multiplier:
I. Active transport of sodium chloride out of the thick ascending limb of Henle's loop is the primary driver of medullary hyperosmolarity. II. The ascending limb is highly permeable to water, allowing water to exit and dilute the interstitium. III. The osmolarity gradient increases from 300 mOsmol/L in the cortex to 1200 mOsmol/L in the inner medullary interstitium. IV. Urea recycling from the collecting duct into the thin ascending limb helps maintain the medullary gradient.
Statements I, III and IV are correct. Statement II is incorrect because the ascending limb is impermeable to water and only transports electrolytes.
Question 80 of 100
📘 CLASS XI
Excretory Products And Their Elimination
Consider these statements about the vascular structure of the renal medulla:
I. The efferent arteriole branches into a fine capillary network surrounding the renal tubules called peritubular capillaries. II. Vasa recta is a specialized, U-shaped capillary vessel that runs parallel to the loop of Henle. III. Vasa recta is highly developed and prominent in cortical nephrons to maximize cortical GFR. IV. The counter current flow of blood in the two limbs of the vasa recta prevents the medullary gradient from being washed out.
Statements I, II and IV are correct. Statement III is incorrect because vasa recta is highly developed only in juxtamedullary nephrons and is absent or poorly developed in cortical nephrons.