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 excretion and osmoregulation regulation of urine formation properties of urine and regulation of urine formation coordination in human beings- chemical control

Angiotensinogen is a protein produced and secreted by

  1. Macula densa cells

  2. Endothelial cells

  3. Liver cells

  4. Juxtaglomerular

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Angiotensinogen is a plasma protein produced and released into the circulation by the liver cells. It is also known as renin substrate. It is the component of the renin-angiotensin system, a hormone system which regulates blood pressure and fluid balance. So, the correct answer is 'Liver cells'.

Multiple choice zoology excretion and osmoregulation regulation of urine formation properties of urine and regulation of urine formation coordination in human beings- chemical control

The maximum amount of electrolytes and water $(70-80\,per cent)$ from the glomerular filtrate is re-absorbed in which part of the nephron?

  1. Ascending limb of loop of Henle

  2. Distal convoluted tubule

  3. Proximal convoluted tubule

  4. Descending limb of loop of Henle
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

About $0-80%$ of the glomerular filtrate is reabosrbed in the proximal convoluted tubule (PCT). Glucose, amino acids, vitamins, hormones, sodium, potassium, chlorides, phosphates, bicarbonates, much of water and some urea are reabsorbed from the filtrate. 

Multiple choice zoology excretion and osmoregulation regulation of urine formation properties of urine and regulation of urine formation coordination in human beings- chemical control

A large quantity of fluid is filtered everyday by nephrons in the kidneys but only about $1%$ of it is excreted as urine. The remaining $99%$ of the filtrate

  1. is stored in the urinary bladder

  2. is re-absorbed into the blood

  3. gets collected in the renal pelvis

  4. is lost as sweat
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A comparison of the volume of the filtrate formed per day ($180$ litres per day) with that of the urine released ($%1.5$ litres). suggests that nearly $99%$ of the filtrate is reabsorbed by the renal tubules into the blood. 

Multiple choice zoology excretion and osmoregulation regulation of urine formation properties of urine and regulation of urine formation coordination in human beings- chemical control

Which of the following will lead to an increase in glomerular fluid filtration in the kidney?

  1. An increase in the protein concentration in the plasma

  2. An increase in the fluid pressure in Bowman's space.

  3. An increase in the glomerular capillary blood pressure.

  4. A decrease in the glomerular capillary blood pressure.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The main driving force favouring fluid filtration from the glomerular capillary to Bowman's space is glomerular capillary blood pressure($P _{GC}$). 

So the correct option is C.

Multiple choice zoology excretion and osmoregulation regulation of urine formation properties of urine and regulation of urine formation coordination in human beings- chemical control

Which one of the following is also known as the antidiuretic hormone?

  1. Oxytocin

  2. Vasopressin

  3. Adrenaline

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

Antidiuretic hormone (ADH) is a hormone that helps your kidneys manage the amount of water in your body. 

ADH is also called arginine vasopressin. It’s a hormone made by the hypothalamus in the brain and stored in the posterior pituitary gland. 
So the correct answer is 'Vasopressin'. 

Multiple choice zoology excretion and osmoregulation regulation of urine formation properties of urine and regulation of urine formation coordination in human beings- chemical control

The function of renin is 

  1. Stimulation of corpus luteum

  2. Vasodilation

  3. To reduce blood pressure

  4. Conversion of angiotensinogen to angiotensin-I
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
The function of renin is to convert angiotensinogen to angiotensin I and further to angiotensin II in response to fall in glomerular blood flow/glomerular blood pressure/GFR. Angiotensin II, being a powerful vasoconstrictor, increases the glomerular blood pressure and thereby GFR. It also activates adrenal cortex  to release aldosterone. Aldosterone causes reabsorption of $Na^{+}$ and water from distal parts of the tubule. This also leads to an increase in blood pressure and GFR.
So, the correct answer is 'Conversion of angiotensinogen to angiotensin-I'.
Multiple choice zoology excretion and osmoregulation regulation of urine formation properties of urine and regulation of urine formation coordination in human beings- chemical control

Suppose you are developing a new drug, and have found that when it is administered in humans, there is a substantial increase in the volume of urine produced. When you administer antidiuretic hormone (ADH or vasopressin) at the same time, the volume of urine returns to normal. Which hypothesis best fits these observations?

  1. Blocks the receptors for ADH on the collecting of the kidney

  2. Blocks the release of ADH from the pituitary

  3. Mimics the action of ADH

  4. Decreases blood pressure
Reveal answer Fill a bubble to check yourself
B Correct answer
Multiple choice zoology excretion and osmoregulation regulation of urine formation properties of urine and regulation of urine formation coordination in human beings- chemical control

The hormone that promotes reabsorption of water from glomerular filtrate is

  1. Oxytocin

  2. Vasopressin

  3. Relaxin

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

Tubular reabsorption is the process by which solutes and water are removed from the tubular fluid and transported into the blood. It is called reabsorption. Reabsorption is a two-step process beginning with the active or passive extraction of substances from the tubule fluid into the renal interstitium, and then the transport of these substances from the interstitium into the bloodstream. These transport processes are driven by Starling forces, diffusion, and active transport. Some key regulatory hormones for reabsorption include: aldosterone, which stimulates active sodium reabsorption; antidiuretic hormone, which stimulates passive water reabsorption. Both hormones exert their effects principally on the collecting ducts.

Multiple choice zoology excretion and osmoregulation regulation of urine formation properties of urine and regulation of urine formation coordination in human beings- chemical control

It there is deficiency of ADH its effect would be

  1. The volume of urine will increase.

  2. The volume of urine will decrease.

  3. The pH of urine will change from 4.8 to 8.00.

  4. Secretion of urochrome takes place.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

ADH targets nephrons in the kidney to increase water reabsorption and thereby decreasing water content in urine. The inability of the neurohypophysial system to produce ADH causes excess urine production with resultant ion loss from the blood. This condition is known as diabetes insipidus (watery urine). This makes option A correct and option B incorrect. Since ADH regulates the urine volume, not its pH, option C is incorrect. Urochrome is the yellow pigment, derived from the breakdown of heme, which is deposited in blood and then is excreted by kidney with urine. This makes option D incorrect. The correct answer is A.

Multiple choice zoology excretion and osmoregulation regulation of urine formation properties of urine and regulation of urine formation coordination in human beings- chemical control

Juxtaglomerular cells secrete A when there is a fall in B concentration. Choose the correct pair labelled as A and B.

  1. A : Renin, B : Chloride

  2. A : Carbonic anhydrase, B : Sodium

  3. A : ATPase, B : Potassium

  4. A : Renin, B : Sodium chloride
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Juxtaglomerular cells are the specialized smooth muscle cells present in the walls of the afferent arterioles that go to the glomerulus. Their function is to produce an enzyme called renin when the osmolarity of blood changes. Renin converts angiotensin secreted by the liver into angiotensin$I$. This is later converted into angiotensin$II$ by an enzyme released by lungs. Angiotensin$II$ acts on adrenal glands to stimulate the release of aldosterone. Aldosterone helps in reabsorption of na+ and water from distal convoluted tubule and the concentration of Na$^+$ ions decreases in the filtrate. 

So juxtaglomerular cells secrete renin when then is fall in sodium chloride  concentration
So, the correct option is D.

Multiple choice zoology excretion and osmoregulation regulation of urine formation properties of urine and regulation of urine formation coordination in human beings- chemical control

A fall in glomerular filtration rate (GFR) activates 

  1. Juxtaglomerular cells to release renin

  2. Adrenal cortex to release aldosterone

  3. Adrenal medulla to release adrenaline

  4. Posterior pituitary to release vasopressin
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A fall in GFR can stimulate the JG cells to release renin which can stimulate the glomerular blood flow and thereby the GFR comes back to normal.

Multiple choice zoology excretion and osmoregulation regulation of urine formation properties of urine and regulation of urine formation coordination in human beings- chemical control

If the concentration of urine  decreases .......... hormone will be released.

  1. LH

  2. FSH

  3. ADH

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

A) LH is Luteinising Hormone which is not involved in the concentration of urine.

B) FSH is Follicle Stimulating Hormone which is not involved in the concentration of urine.
C) ADH (Anti Diuretic Hormone) is responsible for retaining water from the urine and preventing diuresis (dilute urine).
D) Oxytocin is the maternal hormone produced during child birth which is not involved in the concentration of urine.
So the correct answer is 'ADH'.

Multiple choice zoology excretion and osmoregulation regulation of urine formation properties of urine and regulation of urine formation coordination in human beings- chemical control

Absorption of ${ H } _{ 2 }O$ in DCT is controlled by

  1. ADH

  2. ACTH

  3. LH

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

The water reabsorption in the distal part of the nephron is in accordance with the body's state of hydration, under the influence of ADH and is termed as 'facultative reabsorption of water'.  ADH is secreted in the hypothalamus of brain and released into blood stream from the pituitary gland. The collecting ducts become more permeable to water due to the effect of ADH, so more water is reabsorbed by osmosis and no expenditure of ATP energy is required. The release of ADH is triggered when osmoreceptors in the hypothalamus detect an increase in osmolarity of the blood above a set point of ${300 mosm L^{-1}}$. In this situation the osmoreceptors cells also promotes thirst. Drinking reduces the osmolarity of the blood, which inhibits the secretion of ADH.

Multiple choice zoology excretion and osmoregulation regulation of urine formation properties of urine and regulation of urine formation coordination in human beings- chemical control

Renin is secreted by

  1. Cortex

  2. Medulla

  3. Juxta glomerular cells

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

Juxtaglomerular cells are specialized smooth muscle cells of glomerular arterioles. They synthesize, store and secrete the enzyme renin. It plays a critical role in the renin angiotensin system and thus in renal autoregulation of the kidney.

Multiple choice biology animal world oviparous and viviparous diversity and classification in animals adaptations in animals

Terrestrial animals must

  1. Excrete large amounts of urine

  2. Conserve water

  3. Activity pump out salts through skin

  4. Excrete large amount of salts in urine
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

  • Terrestrial organism conserves water as to them less water is available.
  • The urine thus produced is concentrated releasing urea or ammonia.
  • Since ammonia needs a lot of water to get released from the body.
So, the correct option is 'Excrete a large amount of water'.