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LECTURE 1- INTRODUCTION TO HUMAN
PHYSIOLOGY, CELL STRUCTURE AND
ORGANELLES AND GENETICS
1. Which of the following best defines physiology?
a. The study of the structure of the body
b. The study of how the body functions
c. The study of disease processes
d. The study of the chemical composition of cells
Correct Answer: b
Rationale: Physiology is the science that studies the normal
functions of living organisms and their parts. Anatomy studies
structure; pathology studies disease; biochemistry studies
chemical composition.
2. The term “homeostasis” refers to:
a. A state of absolute constancy of the internal environment
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b. The maintenance of a relatively stable internal environment
despite external changes
c. The process of energy production within cells
d. The body’s response to an acute infection
Correct Answer: b
Rationale: Homeostasis is the dynamic maintenance of a stable
internal environment through regulatory mechanisms (e.g.,
temperature, pH, glucose). It does not imply absolute constancy.
3. Which of the following is an example of a negative feedback
mechanism?
a. Blood clotting cascade
b. Oxytocin release during childbirth
c. Regulation of blood glucose by insulin and glucagon
d. Action potential propagation in neurons
Correct Answer: c
Rationale: Negative feedback reverses a change (e.g., high
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glucose → insulin release → glucose decreases). Blood clotting
and childbirth are positive feedback (amplify change). Action
potential propagation is not homeostatic.
4. The internal environment of the body is primarily the:
a. Intracellular fluid
b. Extracellular fluid
c. Blood plasma only
d. Lymph fluid
Correct Answer: b
Rationale: The internal environment is the extracellular fluid
(interstitial fluid + blood plasma) that bathes cells, providing
nutrients and removing wastes. Intracellular fluid is inside cells.
5. Which of the following is NOT a component of a negative
feedback loop?
a. Receptor (sensor)
b. Control center (integrator)
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c. Effector
d. Stimulus amplification
Correct Answer: d
Rationale: Negative feedback opposes the initial stimulus;
amplification is characteristic of positive feedback. The other
three are essential components of all feedback loops.
6. A patient’s body temperature rises to 39°C (102°F). Which of
the following responses would occur to return temperature to
normal?
a. Vasoconstriction of skin blood vessels
b. Shivering
c. Sweating and vasodilation
d. Increased metabolic rate
Correct Answer: c
Rationale: Elevated body temperature triggers heat-loss
mechanisms: sweating (evaporative cooling) and cutaneous
LECTURE 1- INTRODUCTION TO HUMAN
PHYSIOLOGY, CELL STRUCTURE AND
ORGANELLES AND GENETICS
1. Which of the following best defines physiology?
a. The study of the structure of the body
b. The study of how the body functions
c. The study of disease processes
d. The study of the chemical composition of cells
Correct Answer: b
Rationale: Physiology is the science that studies the normal
functions of living organisms and their parts. Anatomy studies
structure; pathology studies disease; biochemistry studies
chemical composition.
2. The term “homeostasis” refers to:
a. A state of absolute constancy of the internal environment
,Page 2 of 71
b. The maintenance of a relatively stable internal environment
despite external changes
c. The process of energy production within cells
d. The body’s response to an acute infection
Correct Answer: b
Rationale: Homeostasis is the dynamic maintenance of a stable
internal environment through regulatory mechanisms (e.g.,
temperature, pH, glucose). It does not imply absolute constancy.
3. Which of the following is an example of a negative feedback
mechanism?
a. Blood clotting cascade
b. Oxytocin release during childbirth
c. Regulation of blood glucose by insulin and glucagon
d. Action potential propagation in neurons
Correct Answer: c
Rationale: Negative feedback reverses a change (e.g., high
,Page 3 of 71
glucose → insulin release → glucose decreases). Blood clotting
and childbirth are positive feedback (amplify change). Action
potential propagation is not homeostatic.
4. The internal environment of the body is primarily the:
a. Intracellular fluid
b. Extracellular fluid
c. Blood plasma only
d. Lymph fluid
Correct Answer: b
Rationale: The internal environment is the extracellular fluid
(interstitial fluid + blood plasma) that bathes cells, providing
nutrients and removing wastes. Intracellular fluid is inside cells.
5. Which of the following is NOT a component of a negative
feedback loop?
a. Receptor (sensor)
b. Control center (integrator)
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c. Effector
d. Stimulus amplification
Correct Answer: d
Rationale: Negative feedback opposes the initial stimulus;
amplification is characteristic of positive feedback. The other
three are essential components of all feedback loops.
6. A patient’s body temperature rises to 39°C (102°F). Which of
the following responses would occur to return temperature to
normal?
a. Vasoconstriction of skin blood vessels
b. Shivering
c. Sweating and vasodilation
d. Increased metabolic rate
Correct Answer: c
Rationale: Elevated body temperature triggers heat-loss
mechanisms: sweating (evaporative cooling) and cutaneous
