What term is synonymous with the fluid component of blood?

Correct Answer: A

Rationale: The correct answer is A: plasma. Plasma is the fluid component of blood, containing water, electrolytes, proteins, hormones, and waste products. It constitutes about 55% of blood volume. Interstitial fluid (B) is found between cells, not in the blood. Extracellular fluid (C) includes both plasma and interstitial fluid. Lymph (D) is a clear fluid derived from interstitial fluid that flows in lymphatic vessels.

Correct Answer: C

Rationale: The primary anion of the intracellular fluid (ICF) is the phosphate ion (C). Phosphate ions play a crucial role in various cellular processes such as energy production (ATP), DNA/RNA synthesis, and buffering intracellular pH. Bicarbonate ion (A) is mainly found in the extracellular fluid, while chloride ion (B) is the major anion in the extracellular fluid. Anionic proteins (D) are not typically considered the primary anion of the ICF. Therefore, the correct choice is C as it best reflects the major anion present in the intracellular fluid.

Correct Answer: B

Rationale: The correct answer is B: urinary output by the kidneys. The kidneys play a crucial role in regulating blood pressure by adjusting the volume of blood in circulation through the control of water and electrolyte balance. Increased urinary output decreases blood volume, leading to a decrease in blood pressure, while decreased urinary output increases blood volume and blood pressure. This long-term regulation mechanism helps maintain blood pressure within a normal range over time. A: the baroreceptor reflex is a short-term regulator that responds to acute changes in blood pressure. C: shifting of fluid between interstitial fluid and plasma may affect blood volume temporarily but is not the primary long-term regulator of blood pressure. D: the thirst mechanism regulates fluid intake to maintain hydration but does not directly regulate blood pressure.

Correct Answer: A

Rationale: The correct answer is A because osmolarity is determined by the total concentration of solutes, both penetrating and non-penetrating, in a solution. In this case, even though the ionic composition may be different between the intracellular fluid (ICF) and extracellular fluid (ECF), the osmolarity remains the same because the overall concentrations of nonpenetrating solutes are equal in both compartments. Choices B and C are incorrect because the permeability of the plasma membrane and protein concentrations do not directly affect osmolarity. Choice D is incorrect because osmolarity refers to the concentration of solutes in a solution, and in this context, it is stated that the osmolarity of both compartments is the same despite the ionic composition differences.

Correct Answer: C

Rationale: To calculate how many times more acidic a pH of 4 is compared to a pH of 7, we use the formula 10^(pH difference). In this case, the pH difference is 7-4 = 3. Therefore, 10^3 = 1000. So, a pH of 4 is 1000 times more acidic than a pH of 7. Choice A (10) is incorrect because it represents a pH difference of 1, not 3. Choice B (100) is incorrect as it represents a pH difference of 2. Choice D (10,000) is incorrect as it represents a pH difference of 4.