EXCRETORY PRODUCTS AND ITS ELIMINATION

ZOOLOGY Lecture – 7

By- SAMAPTI MAM

 Topics to be covered

1 TAPASYA unsolved ppt

4
MY TELEGRAM
QUESTION

The process of excretion involves

1 removal of useful substances from the body.

2 removal of metabolic wastes from the body.

3 removal of essential minerals from the body.

4 None of these
QUESTION

The cortex extends in between the medullary pyramids as renal columns are called;

1 Columns of Bertini.

2 glomerulus.

3 renal corpuscle.

4 renal pelvis.
QUESTION

Which segment of nephron allows the passage of a small amount of urea into the
medullary interstitium?

1 Distal convoluted tubule

2 Loop of Henle

3 Collecting duct

4 Proximal convoluted tubule

QUESTION

The liver secretes cholesterol, degraded steroid hormones, vitamins, and drugs. Most of
these substances ultimately pass out along with;

1 serum.

2 urine.

3 sweat.

4 digestive wastes.
QUESTION

JGA plays a complex regulatory role when;

1 there is a fall in glomerular blood pressure.

2 ADH secretion is at its maximum.

3 there is an increase in glomerular blood flow.

4 All of these
QUESTION

Choose the incorrect pair.

1 Renal calculi - insoluble mass of crystallised salts

2 Kidney transplantation - correction of acute renal failures

3 Atrial natriuretic factor- constriction of blood vessels

4 Glomerular filtration rate- amount of the filtrate formed by the kidneys per minute
QUESTION

Identify the given diagram and choose the option with its correct characteristic.

1 X- Descending limb of loop of Henle; almost impermeable to electrolytes

2 Y- Ascending limb of loop of Henle; permeable to water

3 X- Ascending limb of loop of Henle; impermeable to electrolyte

4
Y- Descending limb of loop of Henle; impermeable to water
QUESTION

Identify A-D in the diagram of Malpighian body (renal corpuscle) and choose the correct
option for A, B, C and D.

1 A-Efferent arteriole, B-Afferent arteriole, C-Bowman's capsule,

D-Distal convoluted tubule

2 A-Afferent arteriole, B-Efferent arteriole, C-Bowman's capsule,

D-Proximal convoluted tubule

3 A-Efferent arteriole, B-Afferent arteriole, C-Bowman's capsule,

D-Distal convoluted tubule

4 A-Afferent arteriole, B-Efferent arteriole, C-Bowman's capsule,

D-Distal convoluted tubule
QUESTION

Read the following statements (I-IV).

I. Kidneys are reddish brown, bean shaped structures.
II. Kidneys are situated between the levels of first thoracic and third lumbar vertebra.
III. Each kidney of an adult human measures 5-7 cm in length, 10-12 cm in width, 2-3 cm
in thickness.
IV. Each kidney of an adult human has average weight of 120- 170 g.
Which of the above statements are incorrect?

1 I, II and III only

2 I and IV only

3 II and III only

4 I, II, III and IV

QUESTION

Read the following statements w.r.t micturition.

(I) The signal for micturition is initiated by the stretching of the urinary bladder as it
gets filled with urine.
(II) The stretch receptors on the walls of the bladder send signals to the PNS.
(III) The contraction of the urethral sphincter causes the release of urine alone.
(IV) The neural mechanisms causing micturition is called the micturition reflex.
Choose the option with the correct statements.

1 II and III

2 I and IV

3 I and III

4 III and IV
 QUESTION
How many of the following statements are incorrect?
(a) The proximity between the Henle’s loop and vasa recta, as well as the counter
in them help in maintaining an increasing osmolarity towards the inner medullary
interstitium.
(b) The medullary interstitium osmolarity gradient is mainly caused by NaCl and urea.
(c) NaCl is returned to the interstitium by the descending portion of vasa recta.
(d) Small amounts of urea enter the thick segment of the ascending limb of Henle’s loop
from interstitium.

1 One

2 Two

3 Three

4 Four
QUESTION

Which of the following statements are true or false?

I. Angiotensin II activates the adrenal medulla to release aldosterone.
II. Aldosterone helps to decrease blood pressure and GFR.
III. ADH facilitates water reabsorption from distal convoluted tubule.
IV. Fall in body fluid volume can switch off the osmoreceptors and suppress the ADH.

1 I and IV are true, but II and III are false.

2 II and IV are true, but I and III are false.

3 I and III are true, but II and IV are false.

4 I, II and IV are false, but only III is true.

QUESTION

Match List-I with List-II to find out the correct option.

1 a- (II), b- (IV), c- (III), d- (I) List-I List-II

(a) Lungs (I) Biliverdin
2 a- (II), b- (III), c- (IV), d- (I)
(b) Liver (II) Waxes

3 a- (IV), b- (I), c- (II), d- (III) (c) Sweat (III) Lactic acid

(d) Sebum (IV) CO2

4 a- (IV), b- (I), c- (III), d- (II)
QUESTION

Statement-I: Renin converts angiotensinogen to angiotensin I.

Statement-II: Angiotensin II is a vasoconstrictor.

1 Statement I and Statement II both are correct.

2 Statement I is correct, but Statement II is incorrect.

3 Statement I is incorrect, but Statement II is correct.

4 Statement I and Statement II both are incorrect.

QUESTION

Statement-I: Malfunctioning of kidneys can lead to uremia.

Statement-II: In patients of uremia, urea can be removed by a process called
hemodialysis.

1 Statement I and Statement II both are correct.

2 Statement I is correct, but Statement II is incorrect.

3 Statement I is incorrect, but Statement II is correct.

4 Statement I and Statement II both are incorrect.

QUESTION

Assertion (A): Some amount of urea may be retained in the kidney matrix of some
animals.
Reason (R): It helps to maintain a desired osmolarity.

1 Both Assertion (A) and Reason (R) are true, and Reason (R) is a correct
explanation of Assertion (A).

2 Both Assertion (A) and Reason (R) are true, but Reason (R) is not a correct
explanation of Assertion (A).

3 Assertion (A) is true, but Reason (R) is false.

4 Assertion (A) is false, but Reason (R) is true.

QUESTION

Assertion (A): Liver also assists in excretion.

Reason (R): It eliminates certain substances like sterols, hydrocarbons and waxes
through sebum.

1 Both Assertion (A) and Reason (R) are true, and Reason (R) is a correct explanation of
Assertion (A).

2 Both Assertion (A) and Reason (R) are true, but Reason (R) is not a correct explanation of
Assertion (A).

3 Assertion (A) is true, but Reason (R) is false.

4 Assertion (A) is false, but Reason (R) is true.

 QUESTION

Assertion (A): Angiotensin II decreases the glomerular blood pressure and thereby GFR.
Reason (R): Aldosterone causes reabsorption of Na+ and water from the distal parts of the
tubule.

1 Both Assertion (A) and Reason (R) are true, and Reason (R) is a correct explanation of Assertion
(A).

2 Both Assertion (A) and Reason (R) are true, but Reason (R) is not a correct explanation o
Assertion (A).

3 Assertion (A) is true, but Reason (R) is false.

4 Assertion (A) is false, but Reason (R) is true.

QUESTION

Assertion (A): Atrial natriuretic factor mechanism acts as a check on the renin-
angiotensin mechanism.
Reason (R): A decrease in blood flow to the atria of the heart can cause the release of
ANF.

1 Both Assertion (A) and Reason (R) are true, and Reason (R) is a correct
explanation of Assertion (A).

2 Both Assertion (A) and Reason (R) are true, but Reason (R) is not a correct
explanation of Assertion (A).

3 Assertion (A) is true, but Reason (R) is false.

4
Assertion (A) is false, but Reason (R) is true.
Question

The conversion of the most toxic nitrogenous waste into a less toxic form in mammals is a
vital metabolic process. Select the option that correctly identifies the site of this
conversion and the immediate destination of the product before its final elimination.
1 Kidney; directly excreted into the collecting duct.

2 Liver; released into the blood for transport to the kidneys.

3 Body cells; diffuses into tissue fluid and then into blood.

4 Spleen; transported to the liver for further processing.

Question

In cases of acute renal failure, the most definitive long-term corrective treatment
mentioned, which requires careful consideration of the host's immune system, is:

1 Hemodialysis

2 Kidney transplantation

3 A low-protein diet

4 Diuretic therapy
Question

The presence of glycosuria and ketonuria in a patient's urine analysis is a strong clinical
indicator of a metabolic disorder affecting:

1 Protein metabolism

2 Fat and carbohydrate metabolism

3 Bilirubin degradation

4 Uric acid synthesis

Question

The unique vascular arrangement in the kidney, where an arteriole drains a capillary bed
and then forms another capillary network, is crucial for renal function. This arrangement is
correctly depicted as:

1 Afferent arteriole → Peritubular capillaries → Efferent arteriole

2 Renal artery → Glomerulus → Efferent arteriole → Vasa recta

3 Afferent arteriole → Glomerulus → Efferent arteriole → Peritubular capillaries

4 Glomerulus → Afferent arteriole → Efferent arteriole → Renal vein

Question

An animal adapted for survival in an extremely arid environment would be expected to

have a higher proportion of juxtamedullary nephrons compared to cortical nephrons. This
anatomical feature is advantageous primarily because juxtamedullary nephrons possess:

1 A more developed peritubular capillary network for enhanced secretion.

2 A larger glomerulus for a higher filtration rate.

3 A very long loop of Henle and an associated vasa recta.

4 A shorter loop of Henle that minimizes the metabolic cost of reabsorption.

Question

The kidneys process approximately 1100-1200 ml of blood per minute. However, the
glomerular filtration rate (GFR) is only about 125 ml/minute. This significant difference is
primarily because:

1 The filtration membrane is impermeable to most blood components.

2 Only the plasma portion of the blood is subjected to filtration, and not all of it passes into the capsule.

The efferent arteriole has a much larger diameter than the afferent arteriole, reducing pressure.
3
Glomerular filtration is an active process that is rate-limited by ATP availability.
4
Question

Given that a healthy person produces 180 litres of glomerular filtrate per day but only
excretes 1.5 litres of urine, this fact is a direct quantitative evidence of the immense
efficiency of:

1 Glomerular filtration

2 Tubular reabsorption

3 Tubular secretion

4 Renin-angiotensin mechanism
Question

The term "conditional reabsorption" in the DCT implies that the reabsorption of Na+ and
water in this segment is:

1 Constant and unregulated

2 Dependent on the body's physiological state

3 Exclusively a passive process

4 Primarily for pH maintenance

Question

In the counter-current exchange system, NaCl transported out of the ascending limb of
Henle’s loop is picked up by the:

1 Descending limb of Henle's loop

2 Descending limb of vasa recta

3 Ascending limb of vasa recta

4 Collecting duct
Question

Suppression of ADH release from the neurohypophysis is a direct physiological response to:

1 Activation of JG cells

2 A decrease in blood pressure

3 Activation of osmoreceptors by fluid loss

4 An increase in body fluid volume

Question

Consider the following events in the regulation of kidney function:

I. Release of Renin from JG cells.
II. Vasoconstriction, leading to an increase in glomerular blood pressure.
III. Conversion of angiotensinogen in blood to angiotensin I.
IV. Secretion of Aldosterone from the adrenal cortex.
V. Reabsorption of Na⁺ from distal parts of the tubule.
What is the correct sequence of events following a fall in GFR?

1 I → III → II → IV → V 2
III → I → II → V → IV
3 4
I → II → III → IV → V
I → III → IV → II → V
Question

Statement I: The glomerular capillary blood pressure causes filtration of blood through 3
layers.
Statement II: The JGA, a special sensitive region, is formed by cellular modifications in the
DCT and the efferent arteriole at their location of contact.

1 Both Statement I and Statement II are correct.

2 Statement I is correct but Statement II is incorrect.

3 Statement I is incorrect but Statement II is correct.

4 Both Statement I and Statement II are incorrect.

Question

Assertion (A): Terrestrial adaptation necessitated the production of lesser toxic

nitrogenous wastes like urea and uric acid.
Reason (R): This adaptation was primarily for conservation of energy, as producing urea
and uric acid is metabolically cheaper than ammonia.

1 Both A and R are true and R is the correct explanation of A.

2 Both A and R are true but R is not the correct explanation of A.

3 A is true but R is false.

4 Both A and R are false.

Question

Consider the location of the human kidneys: "situated between the levels of last thoracic
and third lumbar vertebra close to the dorsal inner wall of the abdominal cavity." Which of
the following is an accurate inference from this statement?

1 The kidneys are retroperitoneal organs.

2 The right kidney is situated slightly higher than the left.

3 The kidneys are protected anteriorly by the floating ribs.

4 The adrenal glands are located on the ventral surface of the kidneys.
Question

Assertion (A): Human kidneys can produce urine nearly four times concentrated than the
initial filtrate formed.
Reason (R): The counter-current mechanism facilitates the creation of a medullary
interstitial gradient from about 300 mOsmolL⁻¹ in the cortex to 1200 mOsmolL⁻¹ in the
inner medulla.

1 Both A and R are true and R is the correct explanation of A.

2 Both A and R are true but R is not the correct explanation of A.

3 A is true but R is false.

4 Both A and R are false.

Question

An adult human excretes, on an average, 25-30 gm of urea per day. If a person's urine
analysis shows an excretion of only 10 gm of urea per day despite normal hydration and
diet, it could be indicative of:

1 Diabetes mellitus

2 Uremia

3 Renal calculi

4 Glomerulonephritis
Question

A person drinks several litres of water. Which of the following physiological

responses would you NOT expect to occur?

1 Suppression of ADH release from the neurohypophysis.

2 Decreased water reabsorption from the DCT and collecting ducts.

3 Activation of JGA to release renin.

4 Release of Atrial Natriuretic Factor (ANF) from the heart.

 Homework

- REVISE CLAASNOTES / ZOOLOGY MED EASY