UPSC-CMS 2024 - Physiology PYQs Practice Questions

Q: Which of the following are approximate daily requirements of the common electrolytes in an adult? 1. Sodium 50-90 mM/day 2. Calcium 25-30 mM/day 3. Potassium 90 mM/day 4. Magnesium 15-17 mM/day Select the correct answer using the code given below.

1, 3 and 4. ***1, 3 and 4*** - The approximate daily requirements for **sodium** are indeed within the range of **50-90 mM/day** (typical maintenance: 1-2 mEq/kg/day) - **Potassium** is around **90 mM/day** (typical maintenance: 1 mEq/kg/day or ~70 mEq/day) - **Magnesium** is typically **15-17 mM/day** (typical maintenance: 0.2-0.3 mEq/kg/day or ~7-10 mM/day) - These values are essential for maintaining proper physiological functions, including fluid balance, nerve impulse transmission, and muscle contraction *2, 3 and 4* - This option incorrectly includes the daily requirement for **calcium** as **25-30 mM/day**, which is approximately **3-4 times higher** than the typical maintenance requirement - Actual adult calcium requirement is approximately **0.1-0.2 mEq/kg/day** or **3.5-7 mM/day** - While potassium and magnesium values are close to accurate, the calcium value makes this option incorrect *1, 2 and 3* - This option incorrectly states the daily requirement for **calcium** as **25-30 mM/day** - The value of **25-30 mM/day** appears to confuse dietary calcium intake (1000-1200 mg/day ≈ 25-30 mmol) with maintenance electrolyte requirements - Although sodium and potassium requirements are correctly stated, the error in calcium makes this choice incorrect *1, 2 and 4* - This combination is incorrect because it includes the inaccurate daily requirement for **calcium** as **25-30 mM/day** - While sodium and magnesium requirements are generally accurate, the inclusion of the incorrect calcium value (should be ~3.5-7 mM/day) invalidates this option [Practice more Physiology PYQs on OnCourse]

Q: Distributive shock is described by which of the following patterns of cardiovascular responses? 1. Vasodilation 2. Reduced peripheral vascular resistance 3. Inadequate 'afterload' 4. Low cardiac output Select the correct answer using the code given below.

1, 2 and 3. ***1, 2 and 3*** - Distributive shock is characterized by **widespread vasodilation** (1), leading to a significant **reduction in peripheral vascular resistance/SVR** (2). - The reduced vascular resistance causes **inadequate afterload** (3) on the heart, as afterload is determined by SVR. - Cardiac output is typically **normal or elevated** in early distributive shock as the heart compensates for the low SVR, so statement 4 is NOT characteristic. - Classic examples include septic shock, anaphylactic shock, and neurogenic shock. *1, 2 and 4* - While **vasodilation** (1) and **reduced peripheral vascular resistance** (2) are correct, **low cardiac output** (4) is NOT a defining feature of distributive shock. - In distributive shock, cardiac output is often elevated in the hyperdynamic phase as the heart compensates for decreased SVR. - Low cardiac output is more characteristic of cardiogenic or hypovolemic shock. *1, 3 and 4* - **Vasodilation** (1) and **inadequate afterload** (3) are correct features, but **low cardiac output** (4) is incorrect. - Distributive shock typically presents with normal or increased cardiac output, not decreased. - This combination incorrectly includes low CO while missing the reduced peripheral vascular resistance (2). *2, 3 and 4* - **Reduced peripheral vascular resistance** (2) and **inadequate afterload** (3) are correct, but this option misses the fundamental mechanism of **vasodilation** (1). - Additionally, **low cardiac output** (4) is not a defining characteristic of distributive shock. - Without mentioning vasodilation, the underlying pathophysiology is incomplete. [Practice more Physiology PYQs on OnCourse]

Q: Which of the following are advantages of state of haemodilution during pregnancy? 1. Optimum gaseous exchange between maternal and foetal circulation due to decreased blood viscosity 2. Protection against adverse effect of blood loss during delivery 3. Increased oxygen carrying capacity of blood Select the correct answer using the code given below.

1 and 2 only. ***1 and 2 only*** - **Haemodilution** during pregnancy, characterized by a disproportionate increase in plasma volume relative to red blood cell mass, leads to decreased blood **viscosity**. - A lower blood viscosity facilitates more efficient **gaseous exchange** (oxygen and carbon dioxide) between the maternal and fetal circulations at the placenta, and also offers a degree of protection against the effects of **blood loss during delivery** by maintaining circulating volume. *1, 2 and 3* - While haemodilution promotes efficient gaseous exchange and protects against blood loss, it does **not increase the oxygen carrying capacity** of the blood. - In fact, the relative decrease in red blood cell concentration leads to physiological anemia of pregnancy, which reduces the oxygen-carrying capacity (though total oxygen delivery may be maintained by increased cardiac output). *2 and 3 only* - This option correctly identifies protection against blood loss but incorrectly states an **increased oxygen carrying capacity**. - The primary mechanism for improved oxygen delivery is enhanced blood flow due to reduced viscosity and increased cardiac output, not an increased concentration of oxygen carriers. *1 and 3 only* - This option correctly identifies improved gaseous exchange but incorrectly suggests an **increased oxygen carrying capacity**. - Protection against blood loss is a significant benefit of pregnancy-induced haemodilution, which is overlooked in this choice. [Practice more Physiology PYQs on OnCourse]

Question 1

Which of the following are approximate daily requirements of the common electrolytes in an adult?

1. Sodium 50-90 mM/day
2. Calcium 25-30 mM/day
3. Potassium 90 mM/day
4. Magnesium 15-17 mM/day

Select the correct answer using the code given below.

Accepted Answer

1, 3 and 4

Answer

2, 3 and 4

Answer

1, 2 and 3

Answer

1, 2 and 4

Question 2

Distributive shock is described by which of the following patterns of cardiovascular responses?

1. Vasodilation
2. Reduced peripheral vascular resistance
3. Inadequate 'afterload'
4. Low cardiac output

Select the correct answer using the code given below.

Accepted Answer

1, 2 and 3

Answer

1, 2 and 4

Answer

1, 3 and 4

Answer

2, 3 and 4

Question 3

Which one of the following statements is correct regarding foetal physiology?

Accepted Answer

Haematopoiesis is demonstrated first in the yolk sac by 14th day.

Answer

Foetal pancreas secretes insulin as early as 20 weeks.

Answer

Meconium appears at 16 weeks.

Answer

Breathing movements are identified at 26 weeks.

Question 4

Which of the following are advantages of state of haemodilution during pregnancy?

1. Optimum gaseous exchange between maternal and foetal circulation due to decreased blood viscosity
2. Protection against adverse effect of blood loss during delivery
3. Increased oxygen carrying capacity of blood

Select the correct answer using the code given below.

Accepted Answer

1 and 2 only

Answer

1, 2 and 3

Answer

1 and 3 only

Answer

2 and 3 only

Question 5

Onset of labour is initiated by which of the following?

Accepted Answer

Increased synthesis of myometrial receptors for oxytocin due to effect of oestrogen

Answer

Increased level of progesterone immediately before labour

Answer

Uterine distension

Answer

Increased CRH and ACTH from foetal hypothalamic-pituitary-adrenal axis

UPSC-CMS 2024 — Physiology