Tag: zoology

Questions Related to zoology

ADH takes part in

  1. Reabsorption of $Na^+$

  2. Reabsorption of watera

  3. Tabular secretion of creatinine

  4. Tubular secretion of urea


Correct Option: B
Explanation:

When excess water is lost through urine the blood volume is decreased and its osmolarity is increased which stimulates the posterior pituitary to release ADH. ADH decreases the volume of urine by increasing the reabsorption of water by kidneys and prevents diuresis. Thus ADH takes part in reabsorption of water.

So, the correct answer is 'Option B'.

Which is correct

  1. An increase in glomerular blood flow stimulates formation of angiotensin II

  2. During summer, when body loses a lot of water by evaporation, the release of ADH is suppressed

  3. When someone drinks a lot of water, ADH release is suppressed

  4. Exposure to cold temperature stimulates ADH release


Correct Option: C
Explanation:

When excess water is lost through urine the blood volume is decreased and its osmolarity is increased which stimulates the posterior pituitary to release ADH.ADH decreases the volume of urine by increasing the reabsorption by kidneys and prevents diuresis. Hence when someone drinks a lot of water, ADH release is suppressed.

So, the correct answer is 'When someone drinks a lot of water, ADH release is suppressed'

Which of the following hormone helps to prevent the diuresis?

  1. FSH

  2. LH

  3. MSH

  4. ADH


Correct Option: D
Explanation:

The term diuresis refers to the excessive production of urine. When excess water is lost through urine the blood volume is decreased and its osmolarity is increased which stimulates the posterior pituitary to release ADH.ADH decreases the volume of urine by increasing the reabsorption by kidneys and prevents diuresis. Hence it is also called antidiuretic hormone.

So, the correct answer is 'ADH'.

Concentration of urine is controlled by

  1. ACTH

  2. MSH

  3. ADH

  4. Oxytocin


Correct Option: C
Explanation:
The hormone ADH (vasopressin) is released from the neurohypophysis (posterior pituitary gland). ADH is synthesized by the hypothalamus and stored in the neurohypophysis. When blood volume is decreased or sodium concentration of blood is increased due to dehydration the ADH is released from the neurohypophysis. ADH causes retention of water by kidneys and maintains blood volume. Hence concentration of urine is controlled by ADH.
So, the correct answer is 'ADH'.

The hormone ADH is released from the 

  1. Adenohypophysis

  2. Neurohypophysis

  3. Adrenal gland

  4. None of the above


Correct Option: B
Explanation:

The hormone ADH (vasopressin) is released from the neurohypophysis (posterior pituitary gland). ADH is synthesized by the hypothalamus and stored in the neurohypophysis. When blood volume is decreased or sodium concentration of blood is increased due to dehydration the ADH is released from the neurohypophysis. ADH causes retention of water by kidneys and maintains blood volume.

So, the correct answer is 'Neurohypophysis'.

Facultative absorption of water from primary urine is influenced by the hormone

  1. Androgens

  2. Epinephrine

  3. Vasopressin

  4. Thyroxine


Correct Option: C
Explanation:

When excess water is lost through urine the blood volume is decreased and its osmolarity is increased which stimulates the posterior pituitary to release vasopressin. Vasopressin(ADH) decreases the volume of urine by increasing the facultative absorption of water by kidneys and prevents diuresis. Hence facultative absorption of water from primary urine is influenced by the hormone vasopressin.

So, the correct answer is 'Vasopressin'.

Intake of ORS inhibits secretion of

  1. Vasopressin

  2. Oxytocin

  3. Melatonin

  4. Thyroxine


Correct Option: A
Explanation:

When excess water is lost through urine the blood volume is decreased and its osmolarity is increased which stimulates the posterior pituitary to release Vasopressin. Vasopressin(ADH) decreases the volume of urine by increasing the facultative absorption of water by kidneys and prevents diuresis. ORS (oral rehydration salt) replaces the lost fluids and essential salts, prevent dehydration and maintain blood volume. Hence Intake of ORS inhibits secretion of vasopressin.

So, the correct answer is 'Vasopressin'.

The juxta glomerular apparatus is a special region formed by close placement and cellular modification in 

  1. Proximal convoluted tubule and distal convoluted tubule

  2. Loop of Henle and collecting duct

  3. Afferent arteriole and distal convoluted tubule

  4. Afferent arteriole and proximal convoluted tubule


Correct Option: C
Explanation:

The juxta glomerular apparatus is a specialised structure made by the glomerular afferent arteriole and the distal convoluted tubule.It is located near the vascular pole of the glomerulus .The main function of juxta glomerular apparatus is to regulate the filteration rate of glomerulus and blood pressure of the body. 

A fall in glomerular filtration rate (GFR) activates

  1. Adrenal cortex to release aldosterone

  2. Adrenal medulla to release adrenaline

  3. Posterior pituitary to release vasopressin

  4. Juxta glomerular cells to release renin


Correct Option: D