Biology

Human Excretion and Kidney Physiology

1,152 Questions

Human excretion and kidney physiology questions test your understanding of the excretory system, including the role of renal tubules and glomerular filtration. You will also find topics on urine formation, body water absorption, and excretory products. This section is vital for medical and general science exam preparation.

Glomerular filtrationRenal tubule absorptionExcretory productsRole of sodium ionsHuman excretory system

Human Excretion and Kidney Physiology Questions

Multiple choice zoology excretory system of human structure of nephron excretory system nephron

In which part uriniferous tubule, $Na^+$ passes out

  1. Descending loop of Henle

  2. Collecting tubule

  3. Ascending loop of Henle

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The nephron is the structural and functional unit of the kidney. It is also called as uriniferous tubule. During the process of urine formation in nephron certain substances are secreted (passes out) and some are reabsorbed along the length of the nephron. The ascending loop of Henle is impermeable to water but allows transport of electrolytes like  Na(+). ions actively or passively.

So, the correct answer is 'Option C'

Multiple choice zoology excretory system of human structure of nephron excretory system nephron

Cells of macula densa produce

  1. Erythropoietin

  2. Renin

  3. Angiotensinogen

  4. Angiotensin
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Macula densa are specialized cells present in the distal convoluted tubule of nephron where distal convoluted tubule come in contact with the afferent renal arteriole of the glomerulus. When blood volume has decreased the cells of macula densa give signals to juxtaglomerular cells to secrete renin enzyme. Hence cells of macula densa produce renin in response to low blood volume by stimulating juxtaglomerular cells.

So, the correct answer is 'Renin'.

Multiple choice zoology excretory system of human structure of nephron excretory system nephron

Juxta-glomerular cells form

  1. Angiotensinogen and angiotensin

  2. Renin and erythropoietin

  3. Counter-current

  4. Selective secretory and absorptive apparatus
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Juxta-glomerular cells are specialized smooth muscle cells of the afferent arteriole, which supplies blood to the glomerulus. When the kidney receives the low volume of blood the juxtaglomerular cells are stimulated to release Renin. When the blood received by kidney have low oxygen levels these cells secrete erythropoietin hormone.
So, the correct answer is 'Renin and erythropoietin'.
Multiple choice zoology excretory system of human structure of nephron excretory system nephron

Which one is the diluting segments of uriniferous tubule?

  1. Ascending loop of Henle

  2. Descending loop of Henle

  3. PCT

  4. DCT
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
The cells of ascending limb actively reabsorb solutes from the luminal fluid and are impermeable to water. As the ions leave the lumen the concentration becomes more and more hypotonic until it reaches approximately 100-150 mOsm/L. The ascending limb is also called the diluting segment of the uriniferous tubule or nephron because of its ability to dilute the fluid in the loop from 1200 mOsm/L to 100 mOsm/L.
So, the correct answer is 'Ascending loop of Henle'.
Multiple choice zoology excretory system of human structure of nephron excretory system nephron

What conditions are responsible for stimulation of juxtaglomerular apparatus?

  1. An increase in blood pressure or blood volume in heart.

  2. An increase in the solute concentration the blood plasma.

  3. A decrease in the solute concentration oil the blood plasma.

  4. Decrease in blood pressure or blood volume in afferent arteriole.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
The juxtaglomerular apparatus is a specialized structure formed by the distal convoluted tubule and the glomerular afferent arteriole. It consists of three cell types: The macula densa, juxtaglomerular cells, and extraglomerular mesangial cells. When the blood pressure or blood volume in afferent arteriole is decreased this condition stimulates the juxtaglomerular cells present in the juxtaglomerular apparatus. The juxtaglomerular cells, derived from smooth muscle cells, of the afferent arteriole, secrete renin when blood pressure in the arteriole falls. Renin increases blood pressure via the renin-angiotensin-aldosterone system. This decrease in blood pressure or blood volume in afferent arteriole is responsible for stimulation of juxtaglomerular apparatus.
So, the correct answer is 'option D'.
Multiple choice zoology excretory system of human structure of nephron excretory system nephron

The nephrons discharge their urine at the:

  1. Urinary bladder

  2. Urethra

  3. Renal pelvis

  4. Renal pyramid (calyses)
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The renal pelvis or pelvis of the kidney is the funnel-like dilated part of the ureter in the kidney. In humans, the renal pelvis is the point where the two or three major calyces join together. Renal pelvis, enlarged upper end of the ureter, the tube through which urine flows from the kidney to the urinary bladder.


So, the correct answer is 'Renal pelvis'.

Multiple choice zoology excretory system of human structure of nephron excretory system nephron

A Malpighian body is constituted by 

  1. Glomerulus only

  2. Glomerulus and Bowman's capsule

  3. Glomerulus and Efferent vessel

  4. Glomerulus, Bowman's capsule and Efferent vessel
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A malphagian body is constituted of two parts - Glomerulus and Bowman's capsule. The glomerulus is the tuft of capillaries and has the filtering apparatus. The Bowman's capsule has a cup-like sack present at the beginning of the tubular component of a nephron.

So, the correct answer is (B).

Multiple choice zoology excretory system of human structure of nephron excretory system nephron

Which is true about the difference between cortical and juxtamedullary nephrons? 

  1. Most nephrons are juxtamedullary.

  2. The efferent arteriole's of cortical nephrons give rise to most of the vasa recta.

  3. The aaferent arterioles of the juxtamedullary nephrons give rise to most of the vasa recta.

  4. Juxtamedullary nephrons generate a hyperosmotic medullary interstitium.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Cortical nephrons either have short or absent loops of Henle. Only juxtamedullary nephrons have long loops of Henle, which plunge into the renal medulla and create a hypersomotic interstitium via counter current multiplication. 

So the correct option is D.

Multiple choice zoology excretory system of human structure of nephron excretory system nephron

Of the total nephrons,the juxtamedullary nephrons constitute ........... %.

  1. 15

  2. 45

  3. 65

  4. 85
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Nephron is the structural and functional unit of the kidney. Juxtamedullary nephrons are found only in birds and mammals. These are juxtamedullary on the basis of their Loop of Henle which is deep in the renal medulla and the renal corpuscle is in the medulla and only around 15-20% of the nephrons are juxtamedullary.

Multiple choice zoology excretory system of human structure of nephron excretory system nephron

Difference between glomerular filtrate and plasma is of

  1. Proteins

  2. Potassium

  3. First is white whereas latter is yellow.

  4. First is yellow whereas latter is white.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Blood plasma contains red and white blood cells, blood proteins, glucose, water, nitrogenous wastes, salt. Glomerular filtrate contains glucose, salt, water, nitrogenous wastes. Blood cells and plasma proteins are not filtered through the glomerular capillaries because they are relatively larger in size.

Multiple choice zoology excretory system of human structure of nephron excretory system nephron

The renal threshold value of glucose is normally

  1. 80 mg/100 ml

  2. 160-180 mg/100 ml

  3. 100-120 mg/100 ml

  4. 80-110 mg/100 ml
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The proximal tubule can only reabsorb a limited amount of glucose. When the blood glucose level exceeds about 160-180 mg/dl or 160-180 mg/100ml, the proximal tubule becomes overwhelmed and begins to excrete glucose in the urine. this point is called the renal threshold of glucose (RTG).
So, the correct answer is option B.

Multiple choice zoology excretory system of human structure of nephron excretory system nephron

Function of glomerulus in mammalian kidney is

  1. Reabsorption of salts

  2. Urine formation through blood filtration

  3. Urine collection

  4. All of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A glomerulus is a network of capillaries responsible for the filtration of blood in the nephron the functional unit of the kidney. The glomerulus is surrounded by a single layer of epithelium called the Bowman's capsule constitute a renal corpuscle, the basic filtration unit of the kidney. 

So, the correct answer is option B.

Multiple choice zoology excretory system of human structure of nephron excretory system nephron

The size of the filtration slits present in the glomerulus is

  1. 10 cm.

  2. 15 nm.

  3. 25 nm.

  4. 10 nm.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The filtration slits present in the endothelium of the glomerulus are of the size 25 nm that can allow the plasma and solutes to diffuse in but not the blood cells. So the filtrate in the Bowman's Capsule that has diffused in from the glomerulus is colourless due to an absence of RBCs.

Hence, the correct answer is '25 nm'.

Multiple choice biology the world of microbes protista protozoa five kingdoms of living organisms

Read the following statements.

  1. Contractile vacuoles eliminates excess water from the body

  2. Glomerular kidney is present in Fresh water fishes

  3. A glomerular kidney possess less no. of nephrons

  4. Chloride cells are present on the stomach wall of frog
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Contractile vacuoles are membrane-bound cellular organelle found in many microorganisms. These periodically expand and get filled with water and contract, expelling the contents to the exterior of the cell.

These are very important for maintaining the hydrostatic balance of the particular cell.
It is an important feature of Eukaryotic cell especially protozoa and it plays important role in osmoregulation.
The correct option is 'Contractile vacuoles eliminates excess water from the body'