Excretory Products and their Elimination - Online Test
Q1. During urine formation, the tubular cells secrete ------------------ into the filtrate.
Answer : Option D
Explaination / Solution:
The substances that are secreted into the tubular fluid (for removal from the body) include:
- Potassium ions (K+),
- Hydrogenions (H+),
- Ammonium ions (NH4+),
- creatinine,
- urea,
- some hormones,
- and some drugs (e.g. penicillin).
Q2.
Counter current mechanism :
i. It operates in all vertebrates.
ii. It produces hypertonic urine.
Answer : Option D
Explaination / Solution:
Counter current mechanism operates in mammals but not in all vertebrates. Due to counter current mechanism it produces hypertonic urine, highly concentrated.
Q3.
Read the following statements about urine formation :
i. ultrafiltration doesn’t need any energy expenditure by kidney cells.
ii. selective reabsorption of glucose, water, urea, hormones, amino acids etc takes place through passive transport.
iii. PCT cells have many microvilli along with few mitochondria since most of nutrients are absorbed passively.
Answer : Option A
Explaination / Solution:
During urine formation, ultra filtration takes place in which energy is not required by cells of kidney. Selective reabsorption of glucose , water, salt etc. occurs actively and proximal convoluted tubules (PCT) do not have microvilli.
Q4. If in glomerular capillaries, pressure of blood is 75 mm Hg, osmotic pressure of plasma proteins is 30 mm Hg, and hydrostatic pressure of fluid in renal tubule is 25 mm Hg then net force or the filtration pressure will be calculated as :
Answer : Option D
Explaination / Solution:
Net force of filtration pressure is equal to the blood pressure of glomerular capillaries minus sum of the osmotic pressure of plasma and hydrostatic pressure of fluid in renal tubule. So, filtration pressure = 75 – [ 30 + 20 ] mm Hg.
Q5. The hormone with enzymatic action which catalyses conversion of angiotensinogen into angiotensin is :
Answer : Option B
Explaination / Solution:
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.
Q6. Vasopressin is a hormone involved in regulation of urine formation. It is secreted from :
Answer : Option B
Explaination / Solution:
An excessive loss of fluid from the body can activate receptors which stimulate the hypothalamus to release antidiuretic hormone (ADH) or vasopressin from the neurohypophysis.
Q7. Select the mismatched pair of the following :
Answer : Option D
Explaination / Solution:
Cortical nephron is about 25% of total nephrons. Glomerular filtration rate is 180 litre per day. Juxtamedullary nephron makes about 15% of total nephrons but lung do not removes 180 L of carbon dioxide per day.
Q8. What are the unlabeled a, b & c in the given flow chart ?
Answer : Option D
Explaination / Solution:
Renin convert angiotensin I to angiotensin II which activates adrenal cortex to release aldosterone. Aldosterone helps to reabsorption of sodium and water from DCT.
Q9. Read the following about renal threshold :
i. The renal threshold of glucose is 180 mg/100ml of blood.
ii. If blood level of glucose exceeds 180mg, it leads to diabetes insipidus.
iii. If blood level of glucose exceeds 180mg, it leads to diabetes mellitus.
i. The renal threshold of glucose is 180 mg/100ml of blood.
ii. If blood level of glucose exceeds 180mg, it leads to diabetes insipidus.
iii. If blood level of glucose exceeds 180mg, it leads to diabetes mellitus.
Answer : Option D
Explaination / Solution:
The renal threshold is the state when glucose is present in urine. The renal threshold of glucose is 180 mg/100 ml of blood. If blood glucose level exceeds 180 mg, it leads to diabetes insipidus.
Q10. During micturition, the muscles of urinary bladder and urethral sphincters will
Answer : Option A
Explaination / Solution:
The CNS passes on motor messages to initiate the contraction of smooth muscles of the bladder and simultaneous relaxation of the urethral sphincter causing the release of urine.
