Nephron Structure Practice Questions
20 free Nephron Structure practice questions for the NCERT Biology. Tap an option to answer — you get instant feedback, the correct answer, and a detailed explanation for every question.
Which of the following constitutes the Malpighian body (renal corpuscle)?
- A Glomerulus and Proximal Convoluted Tubule
- B Glomerulus and Bowman's capsule
- C Bowman's capsule and Loop of Henle
- D Afferent and Efferent arterioles
Correct answer: Glomerulus and Bowman's capsule
The Malpighian body is the initial filtering component of a nephron. It consists of the glomerulus—a tuft of capillaries—enclosed by the double-walled, cup-like Bowman's capsule.
The efferent arteriole emerging from the glomerulus forms a fine capillary network around the renal tubule called the:
- A Vasa recta of the medullary network
- B Peritubular capillaries
- C Glomerular capillary tuft
- D Collecting duct epithelium
Correct answer: Peritubular capillaries
The peritubular capillaries arise from the efferent arteriole and surround the proximal and distal convoluted tubules. They are essential for the reabsorption of substances back into the bloodstream.
In cortical nephrons, which of the following structures is either highly reduced or absent?
- A Bowman's capsule
- B Proximal Convoluted Tubule
- C Vasa recta (peritubular vessel)
- D Glomerulus
Correct answer: Vasa recta (peritubular vessel)
Cortical nephrons have a short loop of Henle that extends only very little into the medulla. In these nephrons, the vasa recta—a U-shaped vessel of the peritubular network—is typically absent or highly reduced.
Which part of the nephron is lined by simple cuboidal brush border epithelium to increase the surface area for reabsorption?
- A Bowman's capsule (parietal layer)
- B Proximal Convoluted Tubule (PCT)
- C Ascending limb of Henle's loop
- D Distal Convoluted Tubule (DCT)
Correct answer: Proximal Convoluted Tubule (PCT)
The PCT is specialized for maximum reabsorption. Its brush border epithelium significantly increases the surface area, allowing nearly 70-80 percent of electrolytes and water to be reabsorbed.
Juxtamedullary nephrons differ from cortical nephrons primarily in that they:
- A Lack a loop of Henle and drain directly into the collecting duct
- B Have a very long loop of Henle running deep into the medulla
- C Are much more numerous, making up about 85 percent of all nephrons
- D Are located entirely within the renal pelvis away from the cortex
Correct answer: Have a very long loop of Henle running deep into the medulla
About 15 percent of nephrons are juxtamedullary. They possess long loops of Henle that penetrate deep into the renal medulla, playing a critical role in concentrating urine.
The 'Vasa recta' is a U-shaped minute vessel that runs parallel to the:
- A Proximal Convoluted Tubule
- B Henle's loop
- C Distal Convoluted Tubule
- D Ureter
Correct answer: Henle's loop
The vasa recta is part of the peritubular capillary system. It runs parallel to the loop of Henle and is vital for maintaining the medullary osmotic gradient via the counter-current mechanism.
Which part of the nephron is generally found in the renal medulla?
- A Malpighian corpuscle
- B Proximal Convoluted Tubule
- C Loop of Henle (medullary portion)
- D Distal Convoluted Tubule
Correct answer: Loop of Henle (medullary portion)
The Malpighian corpuscle, PCT, and DCT are always situated in the cortical region of the kidney. The loop of Henle is the specific portion that dips into the medullary region.
The diameter of the afferent arteriole is ________ than that of the efferent arteriole, which helps in creating filtration pressure.
- A Smaller
- B Wider
- C Equal
- D Half
Correct answer: Wider
The afferent arteriole is wider than the efferent arteriole. This difference in diameter creates a high hydrostatic pressure in the glomerulus, which is the driving force for ultrafiltration.
Which of the following is NOT a function of the Proximal Convoluted Tubule (PCT)?
- A Reabsorption of nearly all essential nutrients from the filtrate
- B Maintenance of blood pH and ionic composition
- C Selective secretion of hydrogen and potassium ions into filtrate
- D Concentration of urine by preventing water reabsorption
Correct answer: Concentration of urine by preventing water reabsorption
The PCT is responsible for the bulk reabsorption of water and solutes. Concentrating the urine is primarily the function of the loop of Henle and the collecting duct.
The cells of the visceral layer of Bowman's capsule that wrap around the glomerular capillaries are called:
- A Podocytes (foot-process cells)
- B Choanocytes
- C Nephrocytes
- D Mesangial cells
Correct answer: Podocytes (foot-process cells)
Podocytes are specialized epithelial cells with foot-like processes. They leave small spaces called filtration slits or slit pores through which the blood is filtered.
Which segment of the nephron is nearly impermeable to water but allows the transport of electrolytes actively or passively?
- A Descending limb of Henle's loop
- B Ascending limb of Henle's loop
- C Proximal Convoluted Tubule
- D Collecting duct
Correct answer: Ascending limb of Henle's loop
The ascending limb of the loop of Henle is impermeable to water. This characteristic allows it to transport electrolytes out into the medullary interstitium, making the filtrate increasingly dilute.
The Distal Convoluted Tubule (DCT) of many nephrons opens into a straight tube called the:
- A Ureter (extrarenal duct)
- B Vasa recta network
- C Collecting duct
- D Loop of Henle
Correct answer: Collecting duct
Many DCTs converge and open into a common collecting duct. These ducts run through the medulla and eventually discharge urine into the renal pelvis via the medullary pyramids.
Where does conditional reabsorption of Na+ and water occur under the influence of hormones like aldosterone?
- A Proximal Convoluted Tubule (PCT)
- B Loop of Henle (ascending limb)
- C Distal Convoluted Tubule (DCT)
- D Glomerulus (filtering capillaries)
Correct answer: Distal Convoluted Tubule (DCT)
The DCT is capable of conditional reabsorption of sodium and water. This is a regulated process that helps maintain blood pressure and the ionic balance of body fluids.
Which of the following is the correct order of flow of filtrate through the nephron?
- A Bowman's capsule -> PCT -> Loop of Henle -> DCT -> Collecting duct
- B PCT -> Bowman's capsule -> Loop of Henle -> DCT -> Collecting duct
- C Bowman's capsule -> DCT -> Loop of Henle -> PCT -> Collecting duct
- D Glomerulus -> Loop of Henle -> PCT -> DCT -> Collecting duct
Correct answer: Bowman's capsule -> PCT -> Loop of Henle -> DCT -> Collecting duct
Filtrate is formed in Bowman's capsule and travels through the PCT, then down and up the Loop of Henle, followed by the DCT, before finally entering the collecting duct.
The descending limb of Henle's loop is ________ to water and ________ to electrolytes.
- A Impermeable to water and permeable to electrolytes
- B Permeable to water and almost impermeable to electrolytes
- C Freely permeable to both water and electrolytes
- D Impermeable to both water and electrolytes
Correct answer: Permeable to water and almost impermeable to electrolytes
The descending limb is permeable to water but almost impermeable to electrolytes. As the filtrate moves down, water leaves the tubule into the concentrated medullary fluid, causing the filtrate to become progressively concentrated.
The maintenance of high osmolarity of medullary interstitial fluid is a significant function of which structure?
- A PCT
- B Henle's loop
- C Glomerulus
- D Bowman's capsule
Correct answer: Henle's loop
The loop of Henle, particularly through the counter-current multiplier system, maintains a high osmotic pressure in the medulla. This is essential for the reabsorption of water from the collecting duct.
Which part of the nephron is specifically capable of secreting $NH_3$ and $K^+$ to maintain the ionic balance of the blood?
- A Descending limb of loop of Henle
- B Distal convoluted tubule
- C Ascending limb of loop of Henle
- D Glomerular capillaries
Correct answer: Distal convoluted tubule
The distal convoluted tubule (DCT) performs selective secretion of hydrogen ions, potassium ions, and ammonia. This function is vital for regulating the pH and sodium-potassium balance of the blood.
A Malpighian corpuscle is located in which zone of the kidney?
- A Cortex
- B Medulla
- C Renal pelvis
- D Calyx
Correct answer: Cortex
The Malpighian corpuscles are exclusively found in the renal cortex. This is why the cortical region appears granular under a microscope compared to the striated appearance of the medulla.
The 'hairpin' turn is a characteristic structural feature of the:
- A Proximal Convoluted Tubule
- B The loop of Henle
- C Distal Convoluted Tubule
- D Vasa recta only
Correct answer: The loop of Henle
The loop of Henle is a U-shaped or hairpin-like structure. It consists of a descending limb that dips into the medulla and an ascending limb that returns to the cortex.
The epithelial cells of the PCT have 'brush borders' because they contain:
- A Flagella
- B Cilia
- C Microvilli
- D Pseudopodia
Correct answer: Microvilli
The brush border of the PCT is composed of numerous microvilli. These projections maximize the surface area for the reabsorption of water, glucose, and other vital solutes from the filtrate.