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

Malpighian body is found

  1. In kidney of vertebrates and is involved in the formation of urine

  2. In vertebrates and involved with filtration of blood

  3. In insects and involved in excretion

  4. In vertebrates and involved with filtration of lymph
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Malpighian body is found in the kidneys of the vertebrates. It is also called kidney corpuscle and is composed of a glomerulus and the Bowman's capsule. It is concerned with the filtration of the blood and forms the glomerular filtrate. In insects, the malpighian tubules are present for the excretion.

Hence, the correct answer is 'In vertebrates and involved with filtration of blood'.

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

The opening of the urinary bladder is 

  1. Nephron

  2. Ureter

  3. Urethra

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

Urine is formed in the kidney. The tubes which connect the kidney and urinary bladder are known as the ureter. From the kidney, urine is propelled into the urinary bladder through ureters which are made of smooth muscle fibres. The bladder stores urine, allowing urination to be infrequent and can be controlled. The urethra is a long tube which connects urinary bladder to the urinary meatus for removal of urine from the body. In males, urethra travels through the penis and meet the urethral meatus located at the tip of the penis. In females, urethra connects to the urethral meatus above the vagina. The urethra is also known as the urinary opening. Hence the opening of urinary bladder is urethra.

So,the correct answer is 'Urethra'.

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

Number of uriniferous tubules in the two mammalian kidney are.

  1. Nearly $2$ millions
  2. More than $3$ millions
  3. Less than $1$ million
  4. More than $1$ million
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Each human kidney contains approximately 1 million nephrons, so two kidneys contain approximately 2 million nephrons.

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

Uriniferous tubules are mainly concerned with

  1. Concentration of urine

  2. Passage of urine

  3. Reabsorption of useful substances from glomerular filtrate

  4. Removal of urea from blood
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In humans, the Kidney is the excretory organ. Nephron or uriniferous tubule is the structural and functional unit of the kidney. On an average, 25-30 gm of urea is excreted out per day through urine. Hence uriniferous tubules are mainly concerned with removal of urea from the blood.

So, the correct answer is 'Removal of urea from blood'.

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

Uriniferous/nephrons tubules occur in

  1. Stomach

  2. Testes

  3. Ovary

  4. Kidney
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
The nephron is the structural and functional unit of the kidney. The body of the nephron is divided into renal corpuscle, proximal convoluted tubule (PCT), Henle's loop and distal convoluted tubule( DCT). The nephrons along with collecting ducts are called as uriniferous tubules. Hence uriniferous/nephrons tubules occur in Kidney,
So, the correct answer is 'Kidney'.
Multiple choice zoology excretory system of human structure of nephron excretory system nephron

Part not belonging to uriniferous tubule is

  1. Glomerulus

  2. Henle's loop

  3. Distal convoluted tubule

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

The nephrons along with collecting ducts are called as uriniferous tubule. The nephron is the structural and functional unit of the kidney. The body of the nephron is divided into  Bowman's capsule, PCT, Henle's loop and DCT. Hence glomerulus does not belong to the uriniferous tubule. Glomerulus are the tuft of capillaries present in the Bowman's capsule.

So, the correct answer is 'Glomerulus'.

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

Vital morphological and physiological units of mammalian kidney are

  1. Ureters

  2. Seminiferous tubules

  3. Uriniferous tubules

  4. Nephridia
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
The nephron is the structural and functional unit of the kidney. The body of the nephron is divided into renal corpuscle, PCT, Henle's loop and DCT.which perform the vital functions such as filtration, reabsorption, and secretion. Nephron along with collecting ducts are called as uriniferous tubules. Hence Vital morphological and physiological units of the mammalian kidney are Uriniferous tubules'
So, the correct answer is 'Uriniferous tubules'.
Multiple choice zoology excretory system of human structure of nephron excretory system nephron

Juxtaglomerular cells of renal cortex synthesises an enzyme called 

  1. ADH

  2. Oxytocin

  3. Renin

  4. Urochrome

  5. Glucocorticoids
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Renin is produced in the kidney by the juxtaglomerular cells of renal cortex. It participates in the renin–angiotensin–aldosterone system which maintains the blood pressure and fluid balance in the body. It breaks the angiotensinogen secreted from the liver into a peptide angiotensin I. Angiotensin I is further cleaved into angiotensin II. Angiotensin II acts on the adrenal glands and releases aldosterone which acts on the collecting tubules to absorb more sodium ions which in turn increases the absorption of water and increases the blood volume.  It also acts on the CNS to increase water intake by stimulating thirst. So the correct answer is 'Renin'.

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

Which of the following processes creates high osmotic pressure in uriniferous tubule?

  1. Active secretion of $Na^+$ into efferent arteriole followed by Cl secretion
  2. Active $Na^+$ absorption followed by Cl absorption
  3. Active secretion of $Cl^-$ and absorption of $Na^+$ into efferent arteriole
  4. Active Cl absorption followed by absorption of $Na^+$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The nephron is the structural and functional unit of the kidney. It is also called as uriniferous tubule. The active absorption of Na+ ion followed by the absorption of Cl created high osmotic pressure in the uriniferous tubule.

So, the correct answer is 'Active Na+ absorption followed by Cl absorption'.

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

Number of mitochondria is maximum in part of uriniferous tubule

  1. PCT

  2. Loop of Henle

  3. DCT

  4. Bowmans capsule
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Proximal convoluted tubule (PCT) is lined with cuboidal epithelium with brush border. Almost all essential nutrients and 70-80 % of electrolytes and water are reabsorbed by PCT. The maximum number of mitochondria are present in PCT as the mitochondria support energy requirements of the sodium-potassium pump.
So, the correct answer is 'PCT'.
Multiple choice zoology excretory system of human structure of nephron excretory system nephron

Under low glomerular blood flow, juxta glomerular cells release

  1. Angiotensin I

  2. Angiotensin II

  3. Aldosterone

  4. Renin
Reveal answer Fill a bubble to check yourself
D 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 (low glomerular blood flow)the juxtaglomerular cells are stimulated to release renin.

So, the correct answer is 'Renin'.

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

Juxtaglomerular apparatus is made of

  1. Juxtaglomerular cell, macula densa and lacis cell

  2. Juxtaglomerular cell, lacis cell and myoepithelial cell

  3. Juxtaglomerular cell, lacis cell and Purkinje cell

  4. Juxtaglomerular cell, macula densa and argentaffin cell
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Juxtaglomerular apparatus is a part of nephron present beside glomerulus. These are specialized cells where afferent arteriole come in contact with distal convoluted tubule. The Juxtaglomerular apparatus is made up of the Juxtaglomerular cells(specialized smooth muscle cells of the afferent arteriole), macula densa( specialized cells present in the distal convoluted tubule) and lacis cell.
So, the correct answer is 'Juxtaglomerular cell, macula densa and lacis cell'.
Multiple choice zoology excretory system of human structure of nephron excretory system nephron

A fall in glomerular filtration rate activates

  1. Juxtaglomerular cells to release renin

  2. Adrenal cortex to release aldosterone

  3. Posterior pituitary to release vasopressin

  4. Adrenal medulla to release adrenaline
Reveal answer Fill a bubble to check yourself
A 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. A fall in glomerular filtration rate activates juxtaglomerular cells to release renin. Renin increases blood pressure via the renin-angiotensin-aldosterone system.

So, the correct answer is 'Juxtaglomerular cells to release renin'.

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

Juxtaglomerular cells secrete _________(a) when there is fall in blood pressure (b) ______ ion concentration. Choose the correct option.

  1. a-Renin, b-Chloride

  2. a-Carbonic anhydrase, b-Sodium

  3. a- ATPase, b-Potassium

  4. a-Renin, b-Sodium
Reveal answer Fill a bubble to check yourself
D 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.renin  converts angiotensinogen in blood to angiotensin I and further to angiotensin II. Angiotensin II, being a powerful vasoconstrictor, increases the glomerular blood pressure and thereby GFR. Angiotensin II also activates the adrenal cortex to release Aldosterone. Aldosterone causes reabsorption of Na+ and water from the distal parts of the tubule. This also leads to an increase in blood pressure and GFR.

So, the correct answer is 'a-Renin, b-Sodium'.