Tag: zoology

Questions Related to zoology

Which of the following is a powerful vasconstrictor that increases the glomerular blood pressure and there the GFR?

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

  1. Renin

  2. Angiotensin-II

  3. Aidosterone

  4. ANF

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Correct Option: B
Explanation:
Osmoreceptors in the body are activated by changes in blood volume, body fluid volume and ionic concentration. A fall in glomerular blood flow/glomerular blood pressure/GFR can activate the JG cells to release renin which 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. This complex mechanism is generally known as the Renin-Angiotensin mechanism.
So, the correct option is 'Angiotensin-II'.

Osmoregulation is carried out by

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

  1. Ureter

  2. Nephron

  3. ACTH

  4. ADH

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Correct Option: D
Explanation:

The maintenance of constant osmotic pressure in the fluids of an organism by the control of water and salt concentrations. is called Osmoregulation. It  is carried out by 'anti-diuretic hormone'. 

Vasopressin is responsible for :-

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

  1. Making urine dilute

  2. Dialating the blood vessel

  3. Decreasing filtrate concentration in PCT

  4. Increasing blood pressure

Show answer
Correct Option: D
Explanation:

Vassopressin or anti-diuretic hormone helps prevent loss of water from the body by increasing the reabsorption of water from the kidney and making urine more concentrated. It is also responsible for increasing the blood pressure by constricting the blood vessels. So, the correct option is 'increasing blood pressure'.

Acidification of urine occurs in

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

  1. Proximal tubule

  2. Distal tubule

  3. Loop of henle

  4. None

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Correct Option: A

Choose the odd one out from given option.

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

  1. Renin

  2. ANF

  3. ADH

  4. Aldosterone

Show answer
Correct Option: A
Explanation:

A. Renin is an aspartic protease protein as well as an enzyme which is secreted by the kidneys in the Renin-angiotensin-aldosterone system that regulates the arterial blood pressure.

B. ANF is called the Atrial natriuretic factor, it is a polypeptide hormone (28 amino-acid) is secreted by the atria of the heart in response and acts on the kidney to increase sodium excretion and to inhibit renin secretion.
C. ADH is called Anti-diuretic hormone or vasopressin which produced by the hypothalamus and it regulates and balances the amount of water in the blood.
D. Aldosterone is a mineralocorticoid steroid hormone produced by the adrenal gland which helps in the conservation of sodium in the kidney, salivary glands, sweat glands and colon.
Except for Renin, all others are hormones.
  • So, the correct answer is 'Renin'.

Decreased level of ADH results in the production of _______ 

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

  1. isotonic urine

  2. Hypertonic urine

  3. hyptonic urine

  4. none of these

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Correct Option: A

The opening of urinary bladder is called?

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

  1. Uriniferous tubule

  2. Nephron

  3. Urethra

  4. Ureter

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Correct Option: A

Pituitary controls urine volume through

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

  1. ADH

  2. STH

  3. ACTH

  4. GH

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Correct Option: A
Explanation:

ADH is anti diuretic hormone. It is secreted from posterior pituitary. It stimulates water absorption and hence reduces urine volume.

Glomerular filtration rate would be decreased by:

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

  1. an increase in renal blood flow

  2. Compression of the renal capsule

  3. An increase in afferent arteriolar pressure

  4. Constriction of the efferent arteriole

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Correct Option: A

Drinking of which would lead to the highest rate of ADH secretion?

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

  1. Distilled water

  2. Sea water

  3. Isotonic water

  4. Alcohol

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Correct Option: A