NUR 631/NUR631 Exam 1 V3 | Advanced
Physiology and Pathophysiology Q&A with
Rationale | Grand Canyon University
1. Which process describes the movement of a solute from an area of high concentration to
an area of low concentration across a semi-permeable membrane?
A. Active transport
B. Osmosis
C. Diffusion
D. Endocytosis
Answer: C
Rationale: Diffusion is a passive process that occurs naturally as molecules move down
their concentration gradient. This movement continues until equilibrium is reached
between the two compartments. Unlike active transport, this process does not require the
expenditure of cellular energy in the form of ATP.
2. When a cell shrinks due to a decrease in functional demand or adverse environmental
conditions, it is referred to as:
A. Hypertrophy
B. Hyperplasia
C. Metaplasia
,D. Atrophy
Answer: D
Rationale: Atrophy represents a decrease in cell size which often leads to a reduced size of
the entire organ or tissue. This condition can be physiological, such as the shrinkage of the
thymus during childhood, or pathological due to disuse or loss of nerve supply. It serves as
a survival mechanism allowing the cell to exist with decreased metabolic requirements.
3. Which electrolyte is primarily responsible for maintaining the osmotic pressure of the
extracellular fluid (ECF)?
A. Potassium
B. Calcium
C. Magnesium
D. Sodium
Answer: D
Rationale: Sodium is the most abundant cation in the extracellular fluid and plays a pivotal
role in regulating water balance. By exerting osmotic pressure, it influences the movement
of water between the intracellular and extracellular compartments. Proper sodium levels
are critical for maintaining blood pressure and supporting nerve impulse transmission.
4. A patient presents with a pH of 7.25 and a CO2 level of 55 mmHg. Which acid-base
imbalance is occurring?
A. Metabolic Acidosis
, B. Respiratory Alkalosis
C. Metabolic Alkalosis
D. Respiratory Acidosis
Answer: D
Rationale: Respiratory acidosis is characterized by a decrease in blood pH below 7.35
accompanied by an elevation in carbon dioxide levels. This typically occurs when the lungs
are unable to effectively remove the CO2 produced by the body. The kidneys eventually
attempt to compensate by retaining bicarbonate to buffer the excess acid.
5. Which type of hypersensitivity reaction involves the IgE-mediated release of histamine
from mast cells?
A. Type I
B. Type II
C. Type III
D. Type IV
Answer: A
Rationale: Type I hypersensitivity is an immediate allergic reaction triggered when an
allergen binds to IgE antibodies on mast cells. This binding causes degranulation and the
release of inflammatory mediators like histamine and leukotrienes. These substances lead
Physiology and Pathophysiology Q&A with
Rationale | Grand Canyon University
1. Which process describes the movement of a solute from an area of high concentration to
an area of low concentration across a semi-permeable membrane?
A. Active transport
B. Osmosis
C. Diffusion
D. Endocytosis
Answer: C
Rationale: Diffusion is a passive process that occurs naturally as molecules move down
their concentration gradient. This movement continues until equilibrium is reached
between the two compartments. Unlike active transport, this process does not require the
expenditure of cellular energy in the form of ATP.
2. When a cell shrinks due to a decrease in functional demand or adverse environmental
conditions, it is referred to as:
A. Hypertrophy
B. Hyperplasia
C. Metaplasia
,D. Atrophy
Answer: D
Rationale: Atrophy represents a decrease in cell size which often leads to a reduced size of
the entire organ or tissue. This condition can be physiological, such as the shrinkage of the
thymus during childhood, or pathological due to disuse or loss of nerve supply. It serves as
a survival mechanism allowing the cell to exist with decreased metabolic requirements.
3. Which electrolyte is primarily responsible for maintaining the osmotic pressure of the
extracellular fluid (ECF)?
A. Potassium
B. Calcium
C. Magnesium
D. Sodium
Answer: D
Rationale: Sodium is the most abundant cation in the extracellular fluid and plays a pivotal
role in regulating water balance. By exerting osmotic pressure, it influences the movement
of water between the intracellular and extracellular compartments. Proper sodium levels
are critical for maintaining blood pressure and supporting nerve impulse transmission.
4. A patient presents with a pH of 7.25 and a CO2 level of 55 mmHg. Which acid-base
imbalance is occurring?
A. Metabolic Acidosis
, B. Respiratory Alkalosis
C. Metabolic Alkalosis
D. Respiratory Acidosis
Answer: D
Rationale: Respiratory acidosis is characterized by a decrease in blood pH below 7.35
accompanied by an elevation in carbon dioxide levels. This typically occurs when the lungs
are unable to effectively remove the CO2 produced by the body. The kidneys eventually
attempt to compensate by retaining bicarbonate to buffer the excess acid.
5. Which type of hypersensitivity reaction involves the IgE-mediated release of histamine
from mast cells?
A. Type I
B. Type II
C. Type III
D. Type IV
Answer: A
Rationale: Type I hypersensitivity is an immediate allergic reaction triggered when an
allergen binds to IgE antibodies on mast cells. This binding causes degranulation and the
release of inflammatory mediators like histamine and leukotrienes. These substances lead
